Infill Plot Plans in Lewisham

An infill plot is a small, undeveloped or under-used piece of land within an area that is already built up — the classic examples being a gap between two houses, the wide side garden of a corner property, the end of a terrace, a redundant garage or garage court, a hardstanding or car park, or a pocket of surplus land beside a road. Building a new home on such a plot is 'infill development'. Where the land lies behind existing houses rather than fronting the street — the rear of a deep garden, or a plot reached down a shared drive — the planners call it 'backland development', and it is treated more cautiously because it is harder to give it a proper frontage, access and amenity.

Lewisham draws these distinctions carefully because it treats the different kinds of small site very differently. A genuine gap in a street frontage that a well-designed house could 'repair' is exactly the kind of site the council encourages. A corner plot with its own street frontage on the return road is often a strong opportunity. A backland site buried behind gardens, reached only by passing through the 'demise' (the land) of another property, is one the council is far more likely to resist. And a proposal that simply carves a new plot out of a back garden — 'garden grabbing' — runs straight into the borough's strong protection of garden land. The label your site attracts largely predicts how hard the application will be.

The term 'plot plans' in this context means the full set of drawings that describe the new dwelling and its site: an accurate site survey and location plan, a block plan showing the new home in its plot and its relationship to neighbours, existing and proposed site layouts, and the floor plans, elevations and sections of the house itself. These are not the light-touch drawings that suffice for a small extension. A new home is a full planning application judged against the whole Local Plan, so the plans have to carry a complete, coordinated case — siting, scale, design, amenity, access, parking, refuse, drainage, trees, daylight and more — from the moment they are submitted.

The first thing we establish on any Lewisham infill instruction, therefore, is what kind of site you really have. We survey it, check its frontage and access, measure what a compliant home would need, and test it against the borough's small-sites and garden-land policies. Only once that is settled can we tell you honestly whether a good home is achievable, how big it can be, and by what route — before you spend money designing something the policy was never going to accept. Everything that follows on this page is organised around that central question.

Yes — almost always, and in full. Building a brand-new, self-contained dwelling is not permitted development. The permitted development rights that homeowners rely on for extensions, loft conversions and outbuildings apply to changes to an existing house within its existing curtilage; they do not permit the creation of a wholly new home on a plot. Creating a new dwelling is a material change of use of the land and the erection of a new building, and both require a full planning application to Lewisham Council. There is no prior-approval shortcut for building a new house on a garden or gap site.

This catches people out, because the plot may be part of a garden that 'belongs' to a house that clearly does have permitted development rights. But those rights attach to the existing dwelling and its curtilage — they do not let you sever off part of the garden and build a separate home on it. The moment you propose a new, independent dwelling with its own front door, its own address and its own planning unit, you are in full-application territory, judged against the entirety of the Lewisham Local Plan and the London Plan, not against a checklist of permitted-development limits.

There are a few narrow exceptions and adjacent routes worth knowing about, though none is a substitute for the full application on a normal infill scheme. Certain upward extensions to create new flats can, in limited circumstances, be permitted development under national rights — but those are additions on top of existing buildings, not new houses on the ground, and they carry their own prior-approval tests. Replacement dwellings (knocking down an existing house and building a new one in its place) are also full applications, judged partly on how the replacement compares with the original. For the great majority of infill plots — a gap, a corner, a side or back garden, a garage site — the answer is simply: full planning permission, designed and argued properly.

Because full permission is always needed, the quality of the application is what determines the outcome. Lewisham does not refuse infill on principle — the borough grants new homes on small sites every year and actively wants more of them — but it does refuse the schemes that harm neighbours, lose valued garden land, cram an over-large house onto a tight plot, or provide sub-standard accommodation. The whole of the rest of this page is about designing and arguing a scheme that Lewisham can say yes to.

Lewisham adopted its new Local Plan 2020-2040 on 16 July 2025, replacing the older suite of development-plan documents, and it is against this plan — read together with the London Plan 2021 — that your infill application is judged. Knowing which policies apply lets us build the scheme and the supporting statements around them rather than hoping to satisfy them by accident. Several themes recur on every infill case, and we frame the application around each. (Because a newly adopted plan renumbers policies, we always confirm the exact current policy references for your site at the point of applying.)

The central policy is the one on optimising the use of small housing sites — Policy HO2 in the adopted plan. It explicitly recognises that development on infill and backland sites, on garden land and on amenity areas 'that are sensitive to local context' can play an important role in delivering new housing. That word 'sensitive' is doing a great deal of work: the policy is an invitation to well-designed, context-led infill, and simultaneously a warning against crude intensification. It flows directly from the London Plan's small-sites policy, which encourages boroughs to deliver more homes through the incremental development of exactly these kinds of sites.

Running against that encouragement is the borough's strong protection of garden land. The Local Plan states that garden land makes an important contribution to the character and amenity of Lewisham's neighbourhoods and often has biodiversity value, and that its use for new development should be avoided. Proposals that result in the loss of garden land within enclosed 'perimeter blocks' — the green cores at the centre of a block of surrounding houses — are strongly resisted, and are only considered acceptable in exceptional circumstances. Where garden land is developed at all, the plan expects appropriate re-provision of garden space to mitigate the loss as far as possible. This is the single policy that most often decides a garden-plot or backland scheme.

Beyond these two, an infill application engages the plan's design-quality policies (high-quality, context-responsive design that respects local and historic character), its housing-standards policies (space standards, dwelling mix, accessibility), its residential-amenity policies (daylight, sunlight, outlook, privacy and noise for the new occupiers and the neighbours), its policies on trees, biodiversity and urban greening, on sustainable drainage and flood risk, on parking and sustainable transport, and on heritage where the site is in or near a conservation area. Our job is to design a home, and write the statements, that demonstrate compliance policy by policy so the case officer can recommend approval.

Lewisham is unusual — and helpful — in having produced its own dedicated guidance on building homes on small sites. The council developed a Small Sites Vision and design guidance (published in 2021 and carried forward alongside the new Local Plan) that sets out, site type by site type, what good small-site development looks like in the borough. For anyone contemplating an infill home, this guidance is effectively the council telling you in advance what it wants to see, and designing to it is one of the most reliable ways to earn a positive recommendation.

The guidance classifies the borough's small sites into recognisable types — gaps between buildings, corner and end-of-terrace plots, backland and garden sites, garage and car-park sites, and 'wedge' sites where a plot widens out to a large rear garden — and gives design principles for each. The consistent themes are that a good infill site should have its own clear access and, ideally, its own street or mews frontage; that it should not rely on passing through the demise of another property to reach it; that infill should 'repair harmful breaks in frontage' and be sensitively integrated into the street; and that adjacent properties must keep appropriate garden space and amenity.

That last point about access is decisive on backland and garden schemes. The guidance is clear that garden sites with their own distinct access — a street frontage, or a genuine mews or lane — are far more favourable than plots that can only be reached by driving or walking through someone else's garden or between houses. A corner plot, which by its nature has a frontage on the return road, therefore starts from a much stronger position than a plot marooned at the bottom of a single deep garden. We assess your site against exactly these criteria at the outset, because they largely predict whether the council will engage positively at all.

We use the Small Sites guidance as a design brief, not an afterthought. It tells us how the council thinks about frontage, access, scale, the relationship to neighbours, garden re-provision, trees and greening — and designing the house to answer those points from the first sketch means the application arrives pre-aligned with the council's own stated expectations. On a contested small site, that alignment can be the difference between an approval and a refusal.

Above the borough's own plan sits the London Plan 2021, the Mayor's strategic development plan for the whole capital, and it is a powerful ally for a well-designed infill scheme. The London Plan's small-sites policy — Policy H2 — actively promotes the delivery of new homes on sites of less than 0.25 hectares (2,500 square metres), which covers essentially every ordinary infill and backland plot in Lewisham. It recognises that small sites, developed incrementally across the city, are a major and under-used source of housing, and it presses boroughs to be more supportive of them.

Policy H2 identifies the very site types that make up Lewisham's infill opportunity: new-build homes on vacant or under-used sites; infill in gaps within existing residential frontages; the intensification of existing residential areas; upward extensions; and the redevelopment of existing sites. It sets a strong presumption in favour of well-designed small-site housing, particularly where it takes the form of high-quality infill that fits its context. In principle terms, this is the strategic backing for building on a gap, a corner or an appropriate garden plot.

Just as importantly, the London Plan sets the housing standards your new home must meet regardless of the borough — most notably the nationally described space standard for internal floor areas, minimum private and communal amenity space, dual-aspect and daylight expectations, accessibility standards (a proportion of new homes to be accessible and adaptable, and provision for wheelchair-accessible homes), and cycle-parking standards. These apply to a single infill house just as they do to a large development. A one-off home is not exempt from London-wide quality standards, and designing to them from the start avoids the common trap of a plot that looks big enough until compliant room sizes, storage, amenity space and cycle parking are drawn in.

The interplay between the London Plan's encouragement of small sites and Lewisham's protection of garden land is the terrain on which infill applications are decided. The strategic policy says 'build more on small sites'; the local policy says 'but not by sacrificing our gardens and green cores'. A successful scheme resolves that tension on its own facts — a gap or corner site that adds a home without harming the block will draw on the supportive strand, while a garden-grab in an enclosed perimeter block will run into the protective one. We position each scheme where it belongs in that framework and argue it accordingly.

If there is one test that decides Lewisham infill applications more than any other, it is the treatment of garden land. The council's settled position is that back gardens — especially the collective green space at the heart of a 'perimeter block' of surrounding houses — are a scarce and valuable resource for character, amenity and biodiversity, and it will strongly resist proposals that erode them. This is the concern behind the garden-land policy, and it is why so many plausible-looking garden plots never get planning permission.

In practice, the test bites hardest on backland schemes. A proposal to build a new house at the bottom of a long back garden, in the green core of a block, reached down a narrow shared drive, ticks almost every box the council is worried about: it removes garden land from an enclosed perimeter block, it typically has no proper street frontage, it relies on access through or past other properties, and it can overlook and overshadow every garden around it. The Local Plan tells the council to resist exactly this unless there are exceptional circumstances. Many backland plots are, in candour, not developable at all — and part of our job is to tell you that before you spend money finding out the hard way.

Not all garden and backland development is doomed, however, and the difference lies in the specifics. A corner plot's side garden that has its own frontage on the return road, a wide gap that a modest house could occupy without harming neighbours, or a plot with a genuine independent mews or lane access is a very different proposition from a marooned green core. Where garden land is involved, the council looks for re-provision — a real, usable garden retained for both the existing and the new home — and for evidence that the character of the block and the amenity of every surrounding property survive the change. A scheme that gives the neighbours back proper gardens, keeps the block's green character legible and slots a well-mannered house into a genuine gap can succeed where a crude plot-split cannot.

We assess every infill site against this test first, honestly and early. We look at whether the plot sits in an enclosed perimeter block, whether it has its own frontage and access, what garden the existing and new homes would keep, and how the proposal reads in the character of the block. If the site is a garden-grab that the policy will resist, we say so; if it is a genuine, defensible opportunity, we design and argue it to meet the council's concerns head-on. Getting this judgement right at feasibility is the most valuable thing we do on an infill instruction.

Lewisham is an old part of London with a surprisingly deep and often turbulent history for a borough now defined by railways, high streets and suburban terraces. The modern London Borough of Lewisham was created in 1965 by merging the former metropolitan boroughs of Lewisham and Deptford, and it stretches from the Thames at Deptford in the north down through New Cross, Brockley, Catford and Forest Hill to the green edges of Beckenham Place Park and the Downham and Bellingham estates in the south. That north-to-south spread — riverside industrial past, dense Victorian and Edwardian inner suburbs, and interwar council estates — is exactly why infill has to be judged street by street: the developable gap in one neighbourhood is a protected green core in another.

Deptford, on the borough's northern edge, was one of the most important places in maritime England. Henry VIII founded the Royal Dockyard at Deptford in 1513, and for centuries ships were built and provisioned there; Sir Francis Drake was knighted aboard the Golden Hind at Deptford by Elizabeth I. The playwright Christopher Marlowe, Shakespeare's great contemporary, was killed in Deptford in 1593 in a dispute whose circumstances are still debated. Deptford High Street and Deptford Town Hall are both protected conservation areas today, and the area's layered history sits directly beneath a modern, fast-changing neighbourhood where redevelopment and small-site infill are constant.

Blackheath, straddling the boundary with Greenwich, is one of the borough's grandest landmarks and one of its most historically charged open spaces. It was on Blackheath that Wat Tyler mustered the rebels of the Peasants' Revolt in 1381, and Jack Cade's rebellion assembled there in 1450. The heath is overlooked by fine Georgian and Victorian houses, provides the traditional start of the London Marathon, and lies within the Blackheath Conservation Area — England's first conservation area, designated jointly with Greenwich in 1968. Nearby, Frederick Horniman, a Victorian tea merchant and obsessive collector, gave Forest Hill the Horniman Museum and Gardens, open to the public since 1901 and still one of south London's best-loved attractions. In and around such heritage settings, an infill home faces the highest design and townscape expectations the borough applies.

The borough's more recent history is just as much a part of its identity. In 1977 thousands of local people confronted a National Front march in what became known as the Battle of Lewisham, a defining moment in the area's tradition of activism and its strong sense of a diverse, mixed community. The rivers Ravensbourne and Quaggy, and Deptford Creek, thread through the borough and shaped both its industry and its flood history — the 1968 floods hit Lewisham hard — which is why watercourses, flood risk and sustainable drainage remain live planning considerations on lower-lying infill sites today.

For an infill project, this context is not just colour; it is planning-relevant. A new home within or adjoining one of Lewisham's many conservation areas — Blackheath, Brockley, Telegraph Hill, Ladywell, Lee Manor, Deptford High Street, Forest Hill and others — faces additional design and heritage tests, and the very things an infill scheme wants to do (introduce a new building into a historic frontage, form a new access, remove a garden wall or tree) are exactly what heritage policy scrutinises. Knowing where your plot sits in Lewisham's map, and its history, is the starting point for a credible application.

The reason Lewisham thinks so hard about infill is written into how the borough was built. From the 1850s onwards the arrival of the railways transformed what had been villages and market gardens into dense inner suburbs. When the line reached Blackheath in 1849 and stations opened across the borough, speculative builders threw up mile after mile of Victorian and Edwardian terraces and semis in Brockley, Telegraph Hill, Forest Hill, Lee, Ladywell and Catford. Crucially, that building boom happened plot by plot and street by street, leaving the irregular gaps, over-wide corner plots, coach-house yards and awkward remnants that later generations would eye as infill opportunities.

The twentieth century added new layers and new gaps. Interwar council estates in the south — Downham, Bellingham, Grove Park — brought a different, lower-density grain. Wartime bombing left scars that were filled with post-war housing, some of it itself now being re-examined. And as the motor car arrived, back gardens and mews were filled with garages and garage courts that today, largely redundant, are among the borough's most promising small sites precisely because they already have hardstanding and access and do not touch a garden.

By the late twentieth and early twenty-first centuries, soaring London land values turned every one of those gaps into a potential development. Owners and small developers began splitting plots, building in side and back gardens, and squeezing houses into gaps — and the council grew concerned that the cumulative effect was eroding the green cores of its residential blocks, harming neighbours' amenity, and producing cramped homes on unsuitable land. Garden development became a genuine local flashpoint, echoing a national debate about 'garden grabbing' that led governments to reclassify residential gardens as not being 'previously developed land'.

Lewisham's response was to get organised rather than simply to say no. The borough produced its Small Sites Vision and design guidance to steer infill towards the sites and forms it could support, and it wrote a nuanced small-sites policy into its Local Plan alongside a firm garden-land protection. The message to the development community is consistent: Lewisham needs and welcomes good infill — its housing targets depend on windfall small sites — but it will refuse crude plot-splitting that harms gardens, neighbours or the character of a block. Understanding that history helps you understand the council's mindset: when it assesses your infill scheme, it is weighing your proposal against a long, deliberate effort to get small-site building right rather than let it happen anyhow.

The strongest infill candidates in Lewisham are the sites the council's own guidance singles out as favourable. A genuine gap in a street frontage — a missing tooth in a terrace, or a wide space between two houses that a modest new home could occupy — is a natural fit, because a well-designed house there 'repairs' the street rather than intruding into a garden. Corner and end-of-terrace plots are often excellent, because the return frontage gives a new home its own address, its own access and its own aspect without borrowing from anyone else's plot. And redundant garage sites and garage courts frequently work well: they usually already have access and hardstanding, and building on them touches no garden at all.

In the middle are the 'wedge' and over-wide plots, where a house sits on a plot that broadens into a large rear garden or side space. These can support a new home, but the design has to be handled carefully so that both the existing and the new dwelling keep a proper garden, a real access and reasonable privacy, and so that the new house sits comfortably in the grain of the street. Whether these work is very site-specific, and depends heavily on frontage, access and the amenity left for the neighbours — which is exactly what the council's small-sites tests examine.

At the difficult end are backland plots in the green cores of perimeter blocks and straightforward back-garden splits with no independent frontage or access. These run headlong into the borough's garden-land protection: they remove garden from an enclosed block, they typically rely on access through or past other properties, and they overlook and overshadow the surrounding gardens. Many such plots simply cannot support a policy-compliant home, and the honest answer at feasibility is that they are undevelopable. It is far cheaper to learn that from a survey and a policy check than from a refused application or a dismissed appeal.

Whatever the plot, the design has to reconcile two things that pull in opposite directions: the owner's wish to get a home (and its value) out of the land, and Lewisham's insistence on protecting gardens, neighbours and the character of the block while delivering a properly sized, well-designed house. The schemes that gain permission treat the council's standards and its garden-land concerns as the design brief rather than as obstacles — and that is precisely how we approach every Lewisham infill plot we draw.

The commonest reason a plausible infill site produces a refused application is that the proposed house is simply too much for the plot. On a small or awkward site, scale, massing and siting are everything, and Lewisham's design-quality policies expect a new home to respond to the prevailing height, footprint, roof form, building line, rhythm and materials of its street rather than to maximise floorspace regardless of context. A house that sits comfortably in the gap — subordinate where it should be, matching the eaves and ridge lines of its neighbours, respecting the building line and the spacing between houses — is far more likely to be approved than one that fills the plot to its edges.

Getting the siting right also protects the neighbours, and neighbour amenity is one of the most reliable grounds of refusal. A new home must not unacceptably overshadow adjoining gardens or windows, must not loom over or box in the neighbours, must not create overlooking that harms their privacy, and must keep adequate separation distances. These are precisely the impacts objectors raise and case officers weigh, and they are designed in — or designed out — at the plan stage. We test daylight, sunlight, outlook and privacy for both the new occupiers and every neighbour as part of the design, not as an afterthought once objections arrive.

The internal design has to deliver a genuinely good home, not just a footprint. That means meeting the nationally described space standard for the overall floor area and every room, providing the required storage, giving habitable rooms proper light and outlook, avoiding poky single-aspect layouts where a dual-aspect home is achievable, and providing private amenity space — a real garden or terrace — for the new dwelling while re-providing garden for the existing house where garden land is affected. A compliant, liveable home on a tight plot is a design problem, and it is solved on the drawing board.

On many Lewisham sites, the context also invites a considered, contemporary response rather than a pastiche. A confident, well-detailed modern infill house can sit more honestly in a varied street — and can satisfy heritage officers in and around conservation areas — than a clumsy imitation of its Victorian neighbours. What matters to the council is quality, coherence and respect for context, however that is expressed. We design each infill home to the specific character of its street and the specific expectations of the area, and we prepare the design-and-access statement that explains and justifies those choices to the case officer.

Every new home in Lewisham has to meet the nationally described space standard, which the London Plan applies across the capital. These are minimum gross internal floor areas and minimum room and storage sizes, and they are a hard edge, not a matter of taste. A one-bedroom, one-person home must be at least 37 square metres; a one-bedroom, two-person home at least 50 square metres as a single-storey dwelling and 58 square metres over two storeys; a two-bedroom, three-person home at least 61 square metres, and a two-bedroom, four-person home at least 70 square metres (79 over two storeys); a three-bedroom, five-person, two-storey house at least 93 square metres, and larger family homes more again. On top of the overall area there are minimum double- and single-bedroom sizes and minimum built-in storage, and every home must have adequate ceiling height.

These standards are why testing the plot honestly at feasibility matters so much. A gap or garden that looks big enough for 'a little house' often shrinks fast once you draw in compliant room sizes, storage, stairs, wall thicknesses, a proper kitchen and living space, and the amenity space and cycle parking the home also needs. Working out the largest genuinely compliant house the plot can take — and whether that house is worth building — is a calculation we do before any commitment, so you are not designing something the standards will not allow.

Beyond floor areas, London-wide policy sets further quality requirements that apply to a single infill home. A proportion of new homes must meet the accessible-and-adaptable standard of the Building Regulations (Part M4(2)), and larger schemes must provide wheelchair-accessible homes (M4(3)); every new home needs secure, convenient cycle storage to the London Plan standard; and each dwelling needs private outdoor amenity space (with a minimum for a one- or two-person home, increasing with occupancy). Dual aspect, good daylight and sunlight, and protection from noise are all expected. None of these is optional because the scheme is small.

We design infill homes to all of these standards simultaneously, because they interact — a bigger footprint to hit the space standard leaves less garden for the amenity requirement; the accessible-home layout affects the plan; the cycle and refuse stores need real space on a tight plot. Resolving them together on the drawings, rather than discovering a clash after submission, is what turns a plot into a home that is both consentable and genuinely good to live in.

A new home needs a way in, somewhere to put the bins, somewhere for bikes and — sometimes — somewhere for a car, and on a small infill plot fitting all of that in is a genuine design challenge that the council examines closely. Access is the first and most important: the site must have a safe, usable pedestrian and (where relevant) vehicular access that does not create highway danger and, critically on garden and backland sites, does not depend on passing through the demise of another property. A corner plot's return-road frontage or a garage site's existing access is a real advantage here; a plot reachable only down someone else's drive is a real problem.

Parking policy in Lewisham is deliberately restrained, in line with the London Plan's car-light approach and the borough's good public transport in much of the north and centre. Many infill homes are expected to be car-free or low-car, especially in areas with a high public-transport accessibility level, and the council will not require — and often will not permit — generous on-plot parking that would harm the design or the street. What it does require is genuinely usable, secure and covered cycle parking to the London Plan standard, designed into the scheme rather than tacked on, because sustainable transport provision is a real part of the assessment.

Refuse and recycling storage is a small thing that sinks schemes. Every new home needs properly sized, accessible bin storage that residents can use and the refuse service can actually reach on collection day, without bins being wheeled long distances through gardens or left on the street. On a tight infill plot, finding a screened, convenient location for the bins — and for the cycle store and any meter boxes — without harming the design or the neighbours takes real thought, and we resolve all of it on the drawings so the council does not have to raise it.

All of these practical elements have to be reconciled with the amenity, privacy and drainage requirements at the same time. The bin store cannot block the neighbour's window; the access cannot funnel headlights into a bedroom; the hardstanding cannot make the site impermeable and worsen flood risk. Coordinating access, parking, cycle and refuse provision with the design, the amenity space and the drainage strategy is part of the craft of a good infill scheme, and it is exactly the sort of detail a hurried application overlooks and a case officer seizes on.

Building a whole new dwelling is a full structural design exercise from the ground up — foundations, floors, walls, roof and the frame that ties them together — and on a tight infill plot it is often more demanding than on an open site, because the new building sits hard against existing structures, gardens, trees and services. Crown handles the architecture, the structure and the building services together, so the drawings you submit are not just a planning layout but a buildable, coordinated scheme. That integration matters more on infill than almost any other project, because the constraints interlock.

Ground conditions come first, and Lewisham's geology and history make them a real consideration. Much of the borough sits on London Clay, a shrinkable clay that moves seasonally and is highly sensitive to nearby trees — a factor on infill plots carved out of mature gardens, where existing or removed trees dictate foundation depth. Lower-lying land near the Ravensbourne, Quaggy and Deptford Creek can bring made ground, high water tables and variable bearing. A site investigation and, where trees are involved, a foundation design to the appropriate depth (often trenchfill or piled foundations near significant trees) are essential, and we design the foundations to the actual ground rather than to a guess.

Proximity to the neighbours drives much of the rest of the structural design. A new house built up to or near a boundary interacts with the neighbours' buildings and land: it may sit alongside a party wall or an existing flank wall, its foundations may fall within the notice distances that trigger the Party Wall etc. Act 1996, and its construction has to protect the adjoining structures throughout. The frame, the foundations and the sequence of construction all have to account for building safely in a confined space with houses on either side — access for materials, temporary support, and the safety of the neighbours' property are part of the design, not just the contractor's problem.

The building fabric then has to meet the current Building Regulations for a whole new dwelling — structural stability (Part A), fire safety (Part B), moisture and weather resistance (Part C), sound (Part E) where the home adjoins another dwelling, ventilation (Part F), drainage (Part H), energy efficiency (Part L), overheating (Part O), and accessibility (Part M). A new build is assessed against the full, current standard, not the gentler regime that applies to alterations, so it is a genuinely high-performance building. Designing the structure, the fabric and the services as one package from the outset is the only way to avoid the classic problem of a plan that looks fine on the planning drawings but cannot be built as drawn.

A new dwelling in Lewisham has to be a genuinely low-energy building, and the standards are rising fast. Today a new home is designed and assessed under the 2021 uplift to Part L of the Building Regulations (in force from June 2022), which requires a new dwelling to produce around 31% less carbon dioxide than one built to the previous 2013 standard — a substantial improvement in fabric, glazing, airtightness and heating that is demonstrated through a SAP energy calculation for the specific design. This is an interim step, and it was explicitly introduced as a stepping stone towards a much higher standard.

That higher standard is the Future Homes Standard. The government published the final Approved Documents for the Future Homes and Buildings Standards on 24 March 2026, with the new requirements coming into force on 24 March 2027 and a twelve-month transitional period running to 24 March 2028. In broad terms it requires new homes to be 'zero-carbon ready', producing very substantially lower emissions than earlier standards — effectively ruling out gas boilers in favour of low-carbon heating such as air-source heat pumps, alongside high-performance fabric and, under the accompanying regulations, on-site renewable electricity generation (solar PV) on new homes where feasible. Any infill home whose building-regulations application falls after the transitional date will be built to this standard.

For an infill project the practical implication is that the energy strategy has to be designed in from the start, not bolted on at building-regulations stage. Where and how a heat pump is sited (and its acoustic impact on the neighbours), how solar panels sit on the roof (a design and sometimes a heritage matter), how the fabric achieves the required airtightness and insulation without cold bridging, and how the home is ventilated and protected from overheating under Part O all affect the architecture. A home designed to hit these targets from the first sketch is cheaper to build and better to live in than one retro-fitted to pass at the end.

London-wide policy adds a further layer. The London Plan's energy hierarchy — be lean, be clean, be green — and its expectation that major development approaches net-zero carbon set the direction, and even a single infill home benefits from being designed to that ambition. We prepare the SAP assessment, coordinate the fabric and services with the energy target, and design the heating, ventilation and any renewables into the building so that the home meets the standard in force when it is built and is genuinely efficient to run.

A new home creates new roof and hard surfaces, new foul drainage and, on a former garden plot, a change from soft, permeable ground to a built surface — all of which have to be managed, and in a borough with Lewisham's flood history the council takes drainage seriously. The rivers Ravensbourne and Quaggy and Deptford Creek run through low-lying parts of the borough, the 1968 floods are within living memory, and surface-water flooding is a live risk across many streets, so both flood risk and sustainable drainage are real planning considerations on infill sites.

Sustainable drainage (SuDS) is the expected approach. Rather than piping rainwater straight into the public sewer, the scheme should manage surface water close to where it falls and mimic natural drainage — through permeable paving, soakaways, rain gardens, green roofs, water butts and attenuation storage — so that the new home does not increase run-off or flood risk downstream. On a garden plot this also helps answer the loss-of-greenery concern, because a green roof or a rain garden re-provides some of the ecological and drainage function of the garden that is built on. The London Plan's drainage hierarchy pushes strongly towards these on-site solutions.

Foul drainage has to be resolved too, and on infill plots the connection is not always straightforward. The new home has to connect to the public foul sewer, which may run under the site, under a neighbour's land, or at a level that requires a pumped connection. Where a public sewer crosses the plot, building over or near it engages the water authority's requirements and may require a build-over agreement, and the foundations and layout have to respect the sewer's position. We establish the drainage strategy — foul and surface water — early, because it can materially affect where the house can go and how it is founded.

Where a site falls within a flood zone or a mapped surface-water flood risk area, a flood risk assessment will be needed, and the design may have to raise finished floor levels, provide flood-resilient construction, or demonstrate that the development is safe over its lifetime. We check the flood mapping at feasibility and, where the site calls for it, prepare or commission the flood risk assessment and the drainage strategy so that the application answers these matters up front rather than being held up by them.

Because so much Lewisham infill takes place on or beside gardens, trees and biodiversity are central to the assessment, and getting them wrong is a common route to refusal. The borough places real weight on its trees — some are protected by Tree Preservation Orders, and any tree in a conservation area enjoys protection — and the loss of a significant tree to make way for a new home is a serious planning objection in its own right, quite apart from the practical foundation issues that trees create on clay soils.

The starting point is a proper tree survey (to the relevant British Standard) that records the trees on and around the site, their condition, and their root protection areas. The design then has to keep the retained trees genuinely viable — respecting their root protection areas in the siting, the foundations and the construction method — rather than retaining them on paper and killing them in practice. Where removal of a lower-value tree is justified, replacement planting is expected, and the arboricultural method statement and tree protection plan become part of the application on any treed site.

Biodiversity is now a formal requirement, not an aspiration. Biodiversity net gain (BNG) applies to development in England, requiring most schemes to demonstrate a measurable net gain in biodiversity, and the London Plan and Lewisham's own policies expect development to enhance greening and habitat. On a former garden plot this is a particular challenge, because building on green land starts from a biodiversity deficit that the scheme then has to more than repair — through planting, green roofs, permeable landscaping and features such as bird and bat boxes. Designing this in from the start is far easier than trying to bolt it on.

The London Plan's urban greening factor pushes in the same direction, expecting new development to include a meaningful proportion of green surfaces — planting, green roofs, permeable ground — rather than hard, sealed surfaces. On an infill home this dovetails with the drainage and garden-re-provision requirements: a green roof, a rain garden and generous planting can simultaneously help the biodiversity, the drainage and the amenity cases. We design the landscape and greening strategy alongside the building so the scheme answers all of these green tests together.

Building a new dwelling creates new floorspace, and new floorspace triggers the Community Infrastructure Levy (CIL) — a charge, calculated per square metre of net additional floorspace, that funds infrastructure. Two levies apply in Lewisham: the Mayor of London's CIL (currently Mayoral CIL2, which funds Crossrail/the Elizabeth line and is charged across London by borough band, with Lewisham in the relevant band) and Lewisham's own borough CIL. Both are set out in charging schedules, are index-linked so the effective rate rises over time, and are calculated from the net new floorspace your scheme creates.

The 'net' matters. CIL is charged on the additional floorspace, so on a genuinely vacant infill plot the whole of the new home counts, whereas a scheme that demolishes an existing building and replaces it may be able to offset the floorspace of the lawful building being lost. There are also reliefs and exemptions worth knowing about: a self-build exemption is available to someone building their own home to live in (subject to strict criteria and a clawback period if they sell or let too soon), and there are exemptions for residential annexes and extensions in defined circumstances. The reliefs are unforgiving on process — they must be claimed and the correct forms served before development starts — so they have to be handled correctly.

The CIL process is procedural and full of traps. An Assumption of Liability and the relevant additional-information and commencement notices have to be submitted at the right stages, and failure to follow the process can forfeit reliefs and trigger surcharges — an expensive mistake on a self-build home in particular. We make sure the CIL position is understood at feasibility (so it is part of your budget from the start) and that the forms and notices are dealt with correctly at each stage, rather than discovered as a surprise bill after the event.

Separate from CIL, some schemes attract planning obligations under a Section 106 agreement — for example contributions or requirements tied to a larger site — though a single infill home is usually below the thresholds that trigger affordable-housing or major obligations. Where obligations do arise, we identify them early and factor them into the appraisal. The point is to give you the full financial picture of the levies and obligations a new home carries, alongside the design, so there are no surprises later.

Many infill schemes involve clearing something first — a garage, an outbuilding, a boundary structure, or occasionally a small building — and building a new home tight against neighbouring properties. Both the clearing and the building bring legal and practical obligations that sit alongside the planning permission and that a well-run project deals with properly rather than leaving to chance.

Demolition may itself require a prior-notification or approval from the council under the Building Act, and, where it affects a party structure, it engages the Party Wall etc. Act 1996. On a tight infill site this Act is very often in play: building a new wall up to the line of junction with a neighbour, excavating foundations within three metres of an adjoining structure (or within six metres in certain deeper-excavation cases), or cutting into a party wall all require formal notice to the affected neighbours and, usually, a party wall award agreed through surveyors. The Act is separate from planning — a planning permission does not remove the party-wall obligations — and ignoring it can bring the job to a halt or expose you to injunctions and claims.

Building safely next to occupied homes is the other reality. A new dwelling squeezed between or behind existing houses has to be built with the neighbours' property and safety protected throughout: temporary support where excavations approach their foundations, protection of their structures during construction, control of noise, dust and hours, and safe access for materials on a constrained site. These practicalities influence the design and the construction sequence, and we design with them in mind so the scheme is genuinely buildable in its confined setting rather than looking good only on paper.

We coordinate the demolition strategy, the party-wall position and the construction approach with the planning and structural design from the outset, and we flag where a party-wall surveyor, a demolition notification or a build-over agreement with the water authority will be needed. Handling the neighbour-facing obligations properly is also, quietly, good planning practice: a scheme that has clearly thought about its neighbours is one that attracts fewer objections and a smoother passage through the council.

An infill new-build application has to tell the council a complete, consistent story: what the site is now, what the new home will be, how it sits with its neighbours and its street, and how it answers every relevant policy. We prepare the full, measured set of plans and the supporting documents that carry the argument, so the application is complete and easy for a case officer to assess and recommend.

The drawing package normally includes an accurate measured survey of the site and, where relevant, the adjoining buildings; an ordnance-based location plan and a block plan showing the new home in its plot; existing and proposed site layout plans showing the building footprint, access, parking, cycle and refuse stores, amenity space, boundary treatments, trees and levels; and the floor plans, elevations and sections of the new house itself, drawn to scale with room and overall floor areas annotated so the council can check them against the space standard. Street-scene elevations showing the new home alongside its neighbours are often decisive on infill, because they let the case officer see at a glance that the scale and design fit the street.

Alongside the drawings we prepare the supporting documents the scheme requires. That typically includes a planning statement addressing the Lewisham Local Plan and London Plan policies (small sites, garden land, design, amenity, standards, transport, sustainability); a design and access statement explaining and justifying the design; and, depending on the site, a daylight/sunlight assessment, an arboricultural survey and method statement, an ecology or biodiversity net-gain assessment, a flood risk assessment and drainage strategy, a transport or parking statement, a heritage statement where the site is in or near a conservation area, and the energy/SAP information. We commission or coordinate the specialist reports and make sure they all agree with the drawings.

Everything is prepared to be internally consistent — the floor areas on the plans match the schedule and the statements, the daylight assessment matches the layout, the drainage strategy matches the levels, the tree constraints match the siting and the foundations. A coordinated, self-consistent application is materially more likely to be approved than a set of drawings and reports that contradict each other, and it is far easier for a case officer to recommend than a package they have to reconcile themselves.

The process starts with feasibility, and on an infill plot this stage is worth more than on almost any other project. We survey the site, check its planning history and constraints (conservation area, TPOs, flood zone, sewers, PTAL), establish whether it has a real frontage and access, and test it against the borough's small-sites and garden-land policies and the national space standards. This is where we tell you honestly whether a good home is achievable, how big it can realistically be, and whether the scheme stacks up — before you spend money on a full application the policy was never going to accept.

On a contested infill site, pre-application advice from Lewisham is frequently worthwhile. A written steer from the council on the principle of development, the acceptable scale and the key concerns lets us develop the scheme in the right direction before committing to a full submission, and it signals to the eventual case officer that the proposal has been developed thoughtfully in dialogue with the council. On genuinely marginal garden and backland plots, a pre-application response can also save you the cost of a doomed application.

We then prepare the full application — the coordinated drawings, the planning and design-and-access statements, and the technical assessments the site requires — and submit it through the Planning Portal, managing it through validation and determination. A householder-style new-build application is determined against roughly an eight-week target, though infill schemes that attract objections, or that need to be negotiated with the case officer, can take longer. We handle the case-officer dialogue, respond to consultation comments and neighbour objections, and negotiate amendments where that will secure approval rather than let the application drift to refusal.

Once permission is granted, we take the scheme forward into the building-regulations and construction information, so the same coordinated team that secured the approval also delivers the drawings your builder and the building-control body need — the full structural design, the Part L energy and SAP work, the drainage details, and the specifications. Because we design the structure, the energy strategy and the services alongside the planning drawings throughout, the transition from consent to site is far smoother than on projects where those disciplines are bolted on afterwards, and we deal with the CIL notices and any conditions along the way.

Understanding why applications fail is the best way to make sure yours does not. On Lewisham infill schemes, the most common single reason for refusal is the unacceptable loss of garden land — a proposal that carves a new home out of a garden in an enclosed perimeter block, harming its green character and biodiversity, runs straight into the borough's strong garden-land protection and is refused unless genuinely exceptional. Closely related is the backland problem: a plot with no proper street frontage, reached through or past another property, that the council's small-sites guidance treats as inherently unfavourable.

The next great cluster of refusals is neighbour amenity. A new home that overshadows adjoining gardens or windows, that looms over the neighbours or boxes them in, that overlooks their private space and harms their privacy, or that leaves inadequate separation is refused on amenity grounds — and these impacts are exactly what objectors raise and case officers test. Overdevelopment is the recurring theme: a house too big for its plot causes the amenity harm, the cramped design and the loss of garden all at once.

Design and character refusals are common too, especially in and around Lewisham's many conservation areas. A new home that ignores the height, footprint, building line, rhythm and materials of its street, or that harms the character or setting of a heritage asset, will be refused on design grounds however well it functions internally. And schemes are refused for the loss of protected or significant trees, for inadequate or unsafe access and highway impacts, for sub-standard accommodation that fails the space standards, for poor drainage or unaddressed flood risk, and for failing to demonstrate biodiversity net gain.

Our approach is to anticipate every one of these reasons and answer it in the application itself. We test the garden-land and backland position honestly at feasibility and only take forward sites that can defend it; we design the scale and siting to protect every neighbour's amenity; we design to the street's character and the conservation-area expectations; we retain trees and demonstrate net gain; and we resolve access, drainage and the space standards on the drawings. We are honest with you at feasibility if a plot is likely to hit an insurmountable problem, because there is no value in submitting an application designed to fail.

The cost of getting an infill home designed, consented and built depends enormously on the plot, the size and design of the house, and the constraints of the site — a straightforward corner plot with its own access is a very different proposition from a tight backland site with trees, a sewer and a party-wall situation. We scope our work to your specific project and give you a clear, fixed fee for our part before any drawing work begins, so you know where you stand from the outset.

Separate from our design fee, you should budget for the council's planning application fee (set nationally for a new dwelling), any pre-application advice fee if you use that service, the building-regulations fees, and the specialist reports the site requires — a tree survey, an ecology or biodiversity assessment, a flood risk assessment and drainage strategy, a daylight/sunlight study, a transport statement or a heritage statement, depending on the constraints. You should also budget for the site investigation and, importantly, for the Community Infrastructure Levy on the new floorspace, which can be a significant sum and which we quantify at feasibility so it is in your appraisal from the start.

On timescales, expect the front end — survey, design, any pre-application dialogue and the preparation of a coordinated application — to take a number of weeks, then a determination period of roughly eight weeks for the planning application, longer where the scheme is contested or negotiated. The building-regulations design and the construction of a new home are substantial programmes in their own right, and a Future Homes Standard house with its low-carbon services and high-performance fabric is a proper build. We give you a realistic overall programme for your specific scheme at the outset so the timescale is planned, not hoped.

It is worth remembering where money is really lost on infill projects: on doomed applications for garden or backland plots the policy was never going to accept, on houses designed too big for their plots that are then refused for overdevelopment, on schemes that ignore trees or drainage or the party-wall position and stall on site, and on CIL reliefs forfeited by missing a procedural deadline. Getting the site judgement, the design and the coordination right first time — and handling the levies and neighbour obligations properly — is by far the most cost-effective way to turn a plot into a home.

To make the process concrete, consider a common Lewisham scenario: a Victorian corner house on a residential street in one of the inner wards, with a wide, under-used side garden that wraps around onto the return road. The owner wonders whether a new home could be built on the side garden. It is exactly the kind of site the council's small-sites guidance treats favourably — a corner plot with a genuine frontage on the return road, its own potential access, and a chance to 'complete' the street — but whether it works depends entirely on the specifics.

At feasibility, we confirm the fundamentals first: the plot has its own frontage and access on the return road, so it does not depend on passing through the existing house's demise; the side garden is not part of a protected enclosed perimeter block; both the existing and the new home can keep a proper garden and amenity space; and the neighbours' daylight, outlook and privacy can be protected. We then test what size of compliant home the plot can take against the national space standards, and this drives the design — a modest two-storey house that matches the eaves and ridge of its neighbours and turns the corner gracefully, rather than an over-scaled block that fills the plot.

The design responds to the street and the neighbours from the first sketch. The new home addresses the return road with its own front door and address; its scale and materials pick up the rhythm and character of the Victorian street; its windows are arranged to avoid overlooking the neighbours' gardens; and it re-provides real private garden for both dwellings. A tree survey confirms the mature street tree can be retained within its root protection area, which sets the foundation design; the foundations are specified as trenchfill to suit the London Clay and the nearby tree.

The technical strategy is built in alongside the design. A sustainable drainage strategy — permeable paving, a soakaway and a rain garden — manages the surface water from the new roof and hardstanding and helps answer the loss-of-greenery concern; the foul connection to the sewer is resolved; the energy strategy is designed to the standard in force, with an air-source heat pump sited to avoid disturbing the neighbours and fabric detailed for airtightness; and secure cycle storage and a screened bin store are designed into the plot. The party-wall position with the adjoining garden boundary is identified so notices can be served at the right time.

On the application side, we prepare the full plot plans — survey, location and block plans, existing and proposed site layouts, and the floor plans, elevations, sections and street-scene drawings with every room and the overall area annotated — plus a planning statement addressing the small-sites and design policies, a design and access statement, and the tree, drainage and daylight information. Submitted to Lewisham, and having been shaped around the council's own small-sites guidance, it goes in as an application the case officer can recommend for approval. Once consented, the same coordinated drawings carry the project through building regulations and onto site, with the CIL notices handled at the right stages. That is the difference between an infill scheme designed to succeed and one hoped through: the site was judged honestly before commitment, the house was sized to the standards and the street rather than to the plot boundary, and the whole scheme was coordinated from the first sketch.

Infill in Lewisham attracts three kinds of client — homeowners who spot a home in their own garden or corner plot, self-builders creating a home to live in, and small developers assembling one or several infill sites — and the discipline that serves all three is the same: never assume a plot is developable. The single most important decision is made before purchase or commitment, when the site is judged honestly against the borough's garden-land and small-sites tests, the space standards, the access and the site constraints. A plot that looks like a gold mine can be undevelopable, and a modest-looking corner or garage site can be a genuine opportunity; the difference is only visible after a proper survey and policy check.

For self-builders, the process carries specific opportunities and traps. The Community Infrastructure Levy self-build exemption can remove a significant cost for someone building their own home to live in — but only if it is claimed correctly, before development starts, and it is subject to a clawback if the home is sold or let within the disqualifying period. Self-builders also have the freedom to create a genuinely bespoke, high-performance home, and designing to the emerging Future Homes Standard from the outset produces a house that is cheaper to run and future-proofed. We guide self-builders through both the design and the procedural pitfalls.

For small developers, the discipline is to build a pipeline of sites that can actually be consented rather than a list of plots that look promising on a map. We can assess a number of potential infill sites across Lewisham, tell you honestly which are realistic and which run into the garden-land or backland barriers, and prioritise the schemes that will deliver the best return for the least planning risk. On tight sites the buildability — access, party walls, foundations, drainage — matters as much as the planning, and designing all of it together avoids the schemes that get consented and then stall on site.

The regulatory direction of travel favours quality over quantity. Rising energy standards, biodiversity net gain, urban greening, restrained parking and the borough's firm garden-land stance all mean that crude, over-dense infill is harder than ever to consent and, frankly, was never a good asset. A well-designed infill home that fits its street, protects its neighbours, meets the standards and holds a proper consent is a durable asset; a house squeezed onto a plot it does not fit is a liability that struggles to be consented, built, sold or let. We design for the former.

Crown Architecture prepares infill new-build schemes across Lewisham and the surrounding boroughs, and we do it as a single coordinated service: the planning design, the structural engineering and the building services under one roof. That integration matters more on infill than almost any other project, because the new home's siting, its foundations on London Clay and around trees, its drainage, its energy strategy and its relationship to the neighbours are completely interdependent — design them separately and they clash; design them together and the plot plans you submit describe a home that is genuinely buildable.

We know the Lewisham regime specifically: the Local Plan 2020-2040 and its Policy HO2 on optimising small housing sites, the borough's strong protection of garden land within enclosed perimeter blocks, its dedicated Small Sites guidance and what it says about frontage, access and design, the London Plan small-sites framework, and the space, energy, drainage, tree and biodiversity standards that decide real applications. We use that knowledge to give you honest advice at feasibility — whether a good home is achievable on your plot, how big it can be, and whether the scheme stacks up — before you commit.

Just as importantly, we are straightforward to work with. We tell you early whether a plot will support a consentable home, we quote a clear fixed fee, and we prepare a coordinated, self-consistent application — designed around the council's own small-sites guidance — that a case officer can recommend without having to fill in the gaps. We lead each scheme with the site judgement and the design that most often decide it, and we build the application around the policies Lewisham actually applies.

We also stay with the project after the drawings are done. We manage the application through Lewisham's determination, engage in pre-application dialogue where it adds value, respond to the case officer and to neighbour objections, and negotiate amendments where that will secure approval. Once consent is in place we carry the scheme through to the building-regulations and construction information your builder and building control need — the structural design, the Part L and SAP energy work, the drainage details and the specifications — and we handle the CIL notices and the discharge of conditions. The aim is a single, accountable point of contact from the first survey to a buildable, consented, high-quality new home.

If you are considering building a new home on an infill plot in Lewisham — a gap, a corner, a side or back garden, or a redundant garage site — send us the address and what you have in mind, and we will tell you honestly whether a good home is achievable, what is realistic, and how to get there.