Energy Statement in Southwark

An energy statement — sometimes called an energy assessment or energy strategy — is a technical report submitted with a planning application that sets out how a development will minimise its energy use and carbon emissions. It is the document through which an applicant demonstrates compliance with the energy and sustainability policies of the development plan: in Southwark, that means the Southwark Plan 2022 and the London Plan 2021, underpinned nationally by Part L of the Building Regulations. Rather than simply asserting that a scheme is 'green', the energy statement quantifies the carbon the building would emit and shows, with recognised calculations, the reduction achieved at each stage of a defined process.

That process is the Mayor of London's energy hierarchy, and the whole structure of an energy statement follows it: 'be lean' (reduce the energy the building needs through efficient fabric and design), 'be clean' (supply that energy efficiently, including through low-carbon heat networks where they exist), 'be green' (generate renewable energy on site), and 'be seen' (monitor and report the building's actual energy performance in use). A well-constructed energy statement works through each stage in turn, presenting the carbon emissions after each step, so the assessor can see exactly how the reductions are being achieved and in what order — because the order matters as much as the total.

The engine behind the numbers is an energy model. For dwellings this is the Standard Assessment Procedure (SAP), the government's methodology for assessing the energy performance of homes; for non-domestic buildings it is the Simplified Building Energy Model (SBEM). The energy statement reports the modelled carbon emissions of the proposed 'actual' building against a defined regulatory baseline, and increasingly also reports metrics such as space-heating demand and energy use intensity (EUI). On major schemes the results must be presented in the Greater London Authority's standard carbon emission reporting spreadsheet, so the GLA and the borough can compare schemes on a like-for-like basis.

It is worth being clear that an energy statement is a planning document, prepared to secure permission, and it interacts with — but is not identical to — the Building Regulations energy compliance you will later demonstrate to building control. The two must line up: the fabric, heating and renewables promised in the planning energy statement have to be the same ones delivered in the Part L submission and built on site. A great deal of the value in preparing the energy statement properly lies in making sure that the planning strategy, the drawings and the eventual construction all tell one consistent story, so the carbon savings promised at planning are the carbon savings actually delivered.

Whether your application needs a full energy statement, a lighter energy and sustainability assessment, or no separate document at all depends chiefly on the scale of the development. Southwark, like every London borough, distinguishes between 'major' and 'minor' development, and the requirements step up sharply for majors. A major residential development is generally one of ten or more dwellings, or on a site of 0.5 hectares or more; a major non-residential scheme is generally one creating 1,000 square metres or more of floorspace, or on a site of one hectare or more. Anything below those thresholds is a minor application.

For a major development, a full energy statement is effectively mandatory. It has to work through the whole energy hierarchy, report against the current Building Regulations baseline, demonstrate the borough's required on-site carbon reduction, and — where net zero cannot be reached on site — calculate the residual carbon and the offset payment. On the largest schemes, including those referable to the Mayor, the energy statement sits within a wider suite of sustainability documents: a whole-life-carbon assessment, a circular economy statement, an overheating (dynamic thermal) analysis and a 'be seen' monitoring commitment. The energy statement is the centre of that suite, and the other documents cross-reference it.

For minor development, the position is more proportionate but the principles still apply. Southwark's validation requirements and its Climate and Environment SPD expect minor schemes to demonstrate how they minimise energy and carbon in line with Policies P69 and P70 — through an energy statement or a sustainability statement appropriate to the scale of the scheme. A new dwelling, a small block of a few flats, a substantial extension or a change of use can all attract a requirement to show the energy and sustainability strategy, even where a full major-scheme energy statement is not needed. The safest approach is to confirm the exact requirement against the council's current validation checklist for your application type before you submit.

There are also cases where an energy statement is triggered less by the number of homes than by the nature of the works — for example, where a proposal involves significant new floorspace, a change of use to residential, or works to a building where sustainability is a specific policy concern. Because the validation requirements are updated from time to time and vary by application type, we always check the live checklist for the specific proposal rather than relying on a rule of thumb. Submitting without a required energy statement is one of the most common reasons an application is held at validation, so getting this right at the outset saves weeks.

Southwark is one of inner London's most historic and most varied boroughs, running south from the River Thames through Bankside and Borough, Bermondsey and Rotherhithe, Walworth and Camberwell, and out to Peckham, Nunhead and the leafy heights of Dulwich. Its story begins in Roman times: around AD 43 the first bridge across the Thames landed here, making Southwark the southern gateway to Londinium. By the medieval period Old Southwark had grown into a bustling market town beyond the City of London's jurisdiction — a place of inns, theatres and freedoms that drew Londoners across the river, and where Chaucer's pilgrims set out from the Tabard Inn on the road to Canterbury.

The modern London Borough of Southwark was created in 1965 by amalgamating the former metropolitan boroughs of Bermondsey, Camberwell and Southwark. Its riverside was for centuries a working landscape of wharves, warehouses and industry — the Bankside power station, the leather and food trades of Bermondsey, the docks of Rotherhithe — and much of that fabric survives, converted and celebrated. Today the borough's Thames frontage is one of the most visited stretches of London: the Tate Modern in the shell of the old Bankside power station, Shakespeare's Globe rebuilt near its original site, Borough Market trading on ground it has occupied for centuries, and, at London Bridge, Renzo Piano's Shard rising 310 metres over the station.

Away from the river, Southwark is a mosaic of very different places: the Georgian and Victorian terraces of Camberwell Grove and Trinity Church Square, the grand villas of Dulwich Village with its picture gallery and college, the twentieth-century estates of Walworth and the Aylesbury, the creative energy of Peckham with Will Alsop's Stirling-Prize-winning library, and the former docklands of Rotherhithe. The borough contains around 48 conservation areas and some 2,200 entries on the National Heritage List for England, so a very large share of development here happens in a heritage-sensitive context, where the visible elements of an energy strategy — solar panels, heat-pump units, rooflights, external insulation — have to be handled with real care.

That mix is central to the energy story here. Southwark faces intense development pressure, from tall towers on the riverside to infill houses and roof extensions across its residential streets, and it does so as one of the country's most climate-driven authorities. The borough declared a climate emergency and has set out to become net zero, and it applies its energy and sustainability policies — Policies P69 and P70 of the Southwark Plan, backed by the Climate and Environment SPD — to development across the whole spectrum. Preparing an energy statement in Southwark therefore means solving a genuinely demanding puzzle: an ambitious low-carbon strategy that also respects a dense, historic, tightly controlled urban context. That is exactly the puzzle our energy statements are designed to solve.

The backbone of every London energy statement is the Mayor's energy hierarchy, set out in Policy SI2 of the London Plan 2021 and applied locally through Southwark's Policy P70. It is a strict order of priority, and an energy statement has to demonstrate that the scheme has worked down it in sequence — not skipped straight to the easy answers. The four stages are 'be lean', 'be clean', 'be green' and 'be seen', and each has a specific meaning that the assessor will look for evidence of in turn.

'Be lean' comes first and matters most: reduce the amount of energy the building needs in the first place, through efficient building fabric and passive design. This is the fabric-first principle — high levels of insulation, airtight construction, thermal-bridge-free detailing, high-performance glazing, and a sensible building form and orientation that captures useful daylight and winter sun while controlling summer overheating. The London Plan is explicit that you cannot buy your way out of the fabric: for major residential development it requires a minimum on-site carbon reduction from energy-efficiency measures alone, before any low-carbon supply or renewables are counted. An energy statement that skimps on 'be lean' fails at the first hurdle.

'Be clean' is the second stage: supply the reduced energy demand as efficiently and cleanly as possible. In London this means, above all, connecting to a low-carbon heat network where one exists, or being designed to connect to a future one. Parts of Southwark fall within Heat Network Priority Areas — areas where heat density is high enough for district heating to be viable — and an energy statement has to investigate connection to any existing or planned network before defaulting to a building-level solution. Where no network is available, the 'be clean' stage considers efficient communal systems and the avoidance of high-carbon supply such as gas boilers.

'Be green' is the third stage: generate renewable energy on site. For most Southwark schemes this means solar photovoltaic (PV) panels on the roof, and increasingly the pairing of a heat pump (which the be-clean and be-green stages now favour over gas) with on-site PV. The energy statement must show that on-site renewable generation has been maximised, sizing the PV array in relation to the available roof area and the building's demand. 'Be seen', the fourth stage, closes the loop: for major schemes the applicant commits to monitor and report the building's actual measured energy performance for the first years of occupation, uploading the data to the GLA's 'be seen' platform, to close the notorious gap between designed and real-world performance. Together the four stages turn a good intention into an evidenced, policy-compliant strategy.

The Southwark Plan 2022 — the borough's Local Plan, adopted on 23 February 2022 — is where the London Plan's energy framework is applied to development in Southwark, and two policies do the heavy lifting. Policy P70 (Energy) requires development to minimise carbon emissions on site by following the energy hierarchy — be lean, then be clean, then be green — and sets the borough's net-zero standard. Policy P69 (Sustainability standards) sits alongside it, addressing the wider sustainability performance of a development, including the requirement to reduce the risk of overheating in line with the cooling hierarchy, taking account of climate change over the lifetime of the building. Both are policies your energy statement has to answer directly.

Policy P70 sets a demanding on-site standard for major development. Major residential development must reduce carbon emissions on site by 100% compared with the Building Regulations baseline — in other words, be net zero carbon on site — and major non-residential development must reduce on-site carbon emissions by a minimum of 40% against the same baseline. Following the update to the calculation baseline, and the council's guidance that applications from 1 January 2023 be assessed against Part L of the 2021 Building Regulations, energy statements now present these reductions against the 2021 Part L baseline rather than the older 2013 one. The energy statement is the document that has to demonstrate the required reduction, or quantify precisely how much is left to be offset.

The detail of how to satisfy these policies is set out in Southwark's Climate and Environment Supplementary Planning Document, adopted in September 2025, which replaced and updated the borough's earlier sustainable-design guidance. The SPD provides practical guidance on Policies P69 and P70 and their London Plan counterparts (SI2 on minimising greenhouse gas emissions, SI3 on energy infrastructure and SI4 on managing heat risks). It sets out what the council expects to see in an energy statement, how minor as well as major development should demonstrate compliance, and how the borough approaches overheating, heat networks, renewable energy and the carbon offset. Preparing an energy statement without reference to this SPD is a common cause of requests for further information.

Reporting conventions matter too. Southwark requires the energy assessment in a major-scheme energy statement to present the carbon reduction achieved on site against the Part L baseline and to include an up-to-date GLA carbon emission reporting spreadsheet as an appendix, so the numbers can be checked in the standard London format. Getting the policy references, the baseline and the reporting format right — and consistent with the drawings — is exactly the kind of detail that determines whether an energy statement is accepted at face value or bounced back with queries, and it is where local knowledge earns its keep.

Where a major development cannot achieve the full on-site carbon reduction that Policy P70 requires — 100% for residential, 40% for non-residential — the remaining, or 'residual', carbon has to be dealt with off site. In practice this almost always means a cash-in-lieu payment into Southwark's carbon offset fund, secured through a Section 106 legal agreement, which the council then uses to fund carbon-reducing projects elsewhere in the borough. The clear policy intent, though, is that offsetting is the last resort, used only after every reasonable on-site measure has been exhausted; a scheme that leans on the offset instead of doing the on-site work will struggle to demonstrate it has worked properly down the hierarchy.

The price of the offset follows the London-wide approach: carbon is valued at £95 per tonne of CO2 for each year, applied over a 30-year period, which works out at roughly £2,850 per tonne of residual carbon when the payment is capitalised and made up front. Southwark increased its offset tariff to this £95 figure in 2020, up from £60 in 2014, aligning the borough with the London Plan carbon price. For a scheme with any meaningful residual carbon, the offset payment can be a substantial sum — which is precisely why it is almost always cheaper, as well as greener, to design the carbon out on site through good fabric, low-carbon heating and renewables than to pay to offset it.

The offset calculation is done in the energy statement itself. Having worked down the hierarchy and established the best achievable on-site reduction, the energy statement quantifies the residual annual carbon emissions, multiplies that by the offset price over the 30-year period, and states the resulting offset contribution. That figure then feeds into the Section 106 negotiation. Because the sum depends directly on how much carbon the on-site strategy saves, a rigorous energy statement — one that squeezes the maximum realistic reduction out of the fabric, systems and renewables — directly reduces the offset bill, sometimes by a great deal.

It is worth understanding what the fund is for. Southwark reinvests offset receipts in projects that cut carbon across the borough — retrofitting existing buildings, improving energy efficiency in council stock, and supporting renewable and low-carbon schemes — so the payment is not a fine but a mechanism for delivering the carbon savings a development could not achieve within its own footprint. Nonetheless, for a developer it is a real cost, and treating the on-site strategy as the priority (with offset as a genuine last resort) is both the policy-compliant approach and, almost always, the commercially sensible one.

A robust energy statement has a recognisable structure that mirrors the energy hierarchy and the reporting conventions the GLA and Southwark expect. It opens by establishing the baseline: the carbon emissions the building would produce if built only to the current Building Regulations (Part L 2021) minimum, calculated in SAP for homes or SBEM for non-domestic space. This baseline is the reference point against which every subsequent saving is measured, so it has to be defined correctly — using the right notional building and the right calculation version — or every reduction figure downstream is wrong.

The body of the statement then works through the hierarchy stage by stage, reporting the carbon emissions after each. The 'be lean' section sets out the fabric and efficiency strategy — U-values, airtightness, glazing, thermal bridging, ventilation and controls — and the demand and carbon reduction it achieves, including the fabric-only reduction the London Plan requires for residential majors. The 'be clean' section addresses heat supply, including the mandatory investigation of connection to a heat network in a Heat Network Priority Area and the choice of an efficient, low-carbon heating system. The 'be green' section quantifies on-site renewable generation, principally solar PV, and its further carbon saving. Each stage carries a carbon figure, so the assessor can trace the reductions in order.

The statement then draws the strands together: the total on-site carbon reduction achieved against the baseline, whether it meets the borough's target (100% for residential majors, 40% for non-residential majors), and, if not, the residual carbon and the resulting offset payment. On major schemes the results are presented in the GLA carbon emission reporting spreadsheet, appended to the statement. Depending on the scheme, the energy statement also addresses or cross-references overheating (a dynamic thermal analysis to CIBSE TM59 for homes or TM52 for non-domestic space, satisfying the cooling hierarchy in Policy P69), energy use intensity and space-heating demand targets, and the 'be seen' commitment to post-occupancy monitoring.

Crucially, the numbers in the energy statement have to be consistent with the rest of the application. The renewables shown on the roof plan must match the PV assumed in the model; the glazing and insulation on the drawings must match the fabric inputs; the heating system in the specification must match the one in the calculation. A common reason energy statements attract queries is internal inconsistency — a statement that promises reductions the drawings cannot deliver. Because we prepare the architecture, the drawings and the energy strategy together, that consistency is built in from the start rather than reconciled after the event.

The single most important part of any energy statement is the 'be lean' stage, because reducing the energy a building needs in the first place is the most reliable and durable way to cut its carbon — and because London policy requires a minimum saving from efficiency alone before any credit is given for clean supply or renewables. A building with an excellent thermal envelope needs very little heating, which makes every downstream decision cheaper: a smaller heat pump, fewer panels, a lower running cost, and a smaller (or zero) offset bill. Skimp on the fabric, and the rest of the strategy is an expensive exercise in compensation.

In an energy statement, 'be lean' is demonstrated through the fabric and efficiency inputs to the SAP or SBEM model and the demand reduction they produce. The key levers are insulation levels (expressed as U-values for walls, roof and floor), airtightness (how little uncontrolled air leaks through the envelope), thermal bridging (the junctions where heat can bypass the insulation), the performance and area of glazing, and the efficiency of the ventilation and controls. In a serious low-carbon scheme this typically means high insulation, triple or high-performance double glazing, careful junction detailing, and mechanical ventilation with heat recovery to keep the air fresh without throwing heat away.

Form and orientation, decided at the earliest design stage, are part of 'be lean' too, and they are free to get right on the drawing board and expensive to change later. A compact building shape loses less heat; sensible window placement captures useful winter sun and daylight while controlling summer solar gain; and thoughtful design balances daylight and views against heat loss. On a tight, overlooked Southwark plot these choices are constrained by neighbours, party walls, privacy and daylight, which is exactly why the architecture and the energy strategy have to be developed together from the outset rather than a standard layout being handed to an energy assessor to model afterwards.

Getting 'be lean' right also protects against the overheating risk that Policy P69's cooling hierarchy addresses. A very well-insulated, airtight, heavily glazed building can trap heat in summer, particularly in a dense, warm inner-London setting, so the fabric strategy has to be designed alongside solar control (orientation, shading, glazing specification) and ventilation to keep the building comfortable in a warming climate. A credible energy statement shows that the demand has been driven down and that overheating has been designed out — the two being different sides of the same fabric-first coin.

Once the fabric has driven demand down, the 'be clean' and 'be green' stages address how the reduced demand is supplied and how much of it is met by on-site renewable generation. In London, 'be clean' begins with heat networks. The energy statement has to establish whether the site falls within a Heat Network Priority Area — an area where heat density makes district heating viable — and, if so, investigate connection to any existing or planned network. Southwark has heat-network activity across parts of the borough, and demonstrating that a connection has been properly considered (and either taken up or reasonably ruled out) is a standard expectation of the 'be clean' assessment.

Where connection to a network is not available or appropriate, the 'be clean' and 'be green' stages together point firmly towards an all-electric, heat-pump-based strategy. With the Building Regulations and the direction of London and national policy moving decisively away from gas, a heat pump — usually an air-source unit on a constrained urban site — is now the default low-carbon heating and hot-water source. It runs on electricity that is steadily decarbonising as the grid greens, and it is what allows a modern scheme to reach the deep carbon reductions Policy P70 demands. The energy statement models the heat pump's efficiency and the carbon saving it delivers over the baseline.

The 'be green' stage quantifies on-site renewable generation, and for most Southwark schemes that means solar photovoltaic panels. The energy statement has to show that PV generation has been maximised for the available roof area, and to model the electricity it produces and the carbon that displaces. On a constrained or heritage-sensitive plot, reconciling the panel array with the roof form, the conservation-area context and the borough's design expectations is part of the design task — one reason the renewables have to be designed in by the architect, not sized abstractly by an energy consultant working from a floor area. Battery storage can be added to make more of the on-site generation.

The recurring theme across 'be clean' and 'be green' is that these systems are inseparable from the architecture and the structure. The heat pump needs a well-considered external location and a route for its pipework, mindful of noise and appearance; the ventilation plant needs duct routes and space designed in; the PV needs a roof that can carry and orient it. Designing these elements in isolation, or bolting them on after the architecture is fixed, is how schemes end up with an energy statement that does not match the drawings — or a building that underperforms in reality. Coordinated design from the outset is the whole point of an integrated practice, and it is what makes the energy statement credible.

The fourth stage of the hierarchy, 'be seen', is a distinctive London requirement and a sign of where the whole system is heading. For major schemes, the applicant commits to monitor the building's actual, measured energy performance once it is occupied and to report that data to the GLA's 'be seen' platform, typically for the first years of operation. The purpose is to close the long-standing 'performance gap' between the energy a building was designed to use and the energy it actually uses. In the energy statement, 'be seen' is a documented commitment — a monitoring strategy — rather than a set of predicted figures, and Southwark will expect to see it on qualifying schemes.

Even where a scheme is too small to be formally caught by 'be seen', the underlying discipline matters: designing so that the building performs in reality as it does on paper, through good detailing, airtightness testing and proper commissioning of the heating, ventilation and renewables. An energy statement is only as good as the building that gets built, and the gap between the two is where many nominally 'green' schemes disappoint. Treating the modelled performance as a genuine target to be verified on site — not just a number to secure permission — is what separates a real low-carbon building from one that is green only in the drawings.

Overheating is the other performance issue that a Southwark energy statement (or its companion sustainability statement) has to address, because Policy P69 requires development to reduce the risk of overheating in line with a cooling hierarchy, taking account of climate change over the building's lifetime. The cooling hierarchy prioritises reducing heat gains first — through orientation, shading, glazing specification and thermal mass — then passive ventilation, then, only as a last resort, active cooling. This is deliberately the opposite instinct to simply installing air conditioning, which would add energy and carbon.

The evidence for overheating is a dynamic thermal analysis: CIBSE TM59 for residential schemes and TM52 for non-domestic buildings. These model the building's temperatures through a realistic weather year and test them against defined comfort criteria, so the design can be shown to stay comfortable without mechanical cooling. In a dense, warming inner-London borough, overheating is a real risk in exactly the well-insulated, airtight, glazed buildings that low-carbon design produces, so the overheating analysis and the energy strategy have to be developed together — reducing carbon and reducing overheating risk at the same time, rather than trading one against the other.

The energy statement measures carbon reductions against a baseline, and that baseline is set by Part L of the Building Regulations — the conservation of fuel and power. Every new building must comply with Part L, demonstrated through a SAP (homes) or SBEM (non-domestic) calculation, and the planning energy statement measures the scheme's performance above that regulatory floor. Southwark's guidance is that planning applications submitted from 1 January 2023 present their carbon reductions against the 2021 edition of Part L, which is a significantly tougher baseline than the previous 2013 edition — so a given percentage reduction against Part L 2021 represents genuinely better performance than the same percentage against the older standard.

Getting the baseline right is not a technicality; it is fundamental. Because every reduction figure in the energy statement is expressed relative to the baseline, using the wrong Part L edition, the wrong notional building or the wrong calculation version invalidates the whole assessment. This is a frequent source of confusion and of requests for further information, and it is one of the reasons the energy statement has to be prepared by someone who knows the current London and Southwark conventions rather than reused from an older template.

The national picture is also moving. The government has confirmed the Future Homes Standard, which will tighten Part L for new homes substantially, driving carbon emissions far below the current baseline and effectively requiring low-carbon heating and on-site renewables as standard. Designing to the direction of that standard now — an all-electric, heat-pump-and-PV home with an excellent fabric — future-proofs a scheme against the tightening baseline and aligns the planning energy strategy with where building control is heading, so the two do not diverge between permission and construction.

The practical implication for a Southwark applicant is clear: there is no sense specifying fossil-fuel heating in a scheme that has to demonstrate deep carbon reductions and will be built and occupied for decades. Both the borough's net-zero policies and the direction of national regulation point to the same building — high-performance fabric, controlled ventilation, a heat pump and on-site PV — and an energy statement built around that model is both easier to make policy-compliant today and safer against tomorrow's rules. Designing to the incoming standard from the start avoids the expensive redesign that catches out schemes built to yesterday's minimum.

We prepare energy statements as an integrated part of the design, not as a document commissioned separately at the end. The process starts at feasibility, where we develop the energy strategy alongside the first design sketches, so the low-carbon logic shapes the building's fabric, form and orientation from the outset. This is the opposite of the common — and often fatal — approach of designing a building first and then asking an energy consultant to model whatever has been drawn: by the time the drawings are fixed, the cheapest and most effective carbon savings (form, orientation, glazing ratio, fabric) are already locked in, and the only levers left are expensive bolt-ons.

We establish the correct baseline (Part L 2021), build the SAP or SBEM model with fabric and systems inputs that genuinely reflect the design, and work through the hierarchy stage by stage — quantifying the be-lean, be-clean and be-green reductions in order, investigating heat-network connection where the site is in a priority area, and maximising on-site renewables for the available roof. We report the total on-site reduction against the borough's target, calculate any residual carbon and the resulting offset payment, and, on major schemes, present the results in the GLA carbon emission reporting spreadsheet and add the overheating analysis and 'be seen' commitment the scheme requires.

Because we also prepare the architecture and the drawings, the energy statement and the rest of the application say the same thing. The insulation and glazing in the model match the specification; the PV in the calculation matches the roof plan; the heat pump in the strategy matches the layout that accommodates it. That internal consistency is not a nicety — it is the difference between an energy statement accepted at face value and one that generates rounds of queries because the numbers and the drawings do not agree. Coordinating the two under one roof removes that risk.

We also right-size the document to the scheme. A referable major tower needs a full energy statement with whole-life-carbon and circular-economy companions; a small block of flats needs a focused energy statement demonstrating Policy P70 compliance; a single new home or a change of use needs a proportionate energy and sustainability statement. We confirm the exact requirement against Southwark's current validation checklist for your application type, and prepare a document that is thorough enough to satisfy the council without loading unnecessary cost onto a smaller scheme.

An energy statement rarely travels alone. On all but the smallest schemes it sits within a family of sustainability and technical documents, and it is important to understand how they relate, because Southwark and the GLA increasingly expect them to be consistent with one another and to cross-reference cleanly. The energy statement is usually the centre of that family: it establishes the operational carbon performance that the others build on or refer to.

The closest companion is the sustainability statement (or sustainable design and construction statement), which addresses Policy P69 and the wider sustainability agenda — water efficiency, materials, the urban greening factor and biodiversity, sustainable drainage, and climate resilience including overheating — of which energy is one part. On smaller schemes the energy content may be folded into a single sustainability statement; on larger ones they are separate but must agree. The design and access statement, meanwhile, explains the design rationale and should reflect the energy strategy in the building's form, roof (for PV) and plant locations.

On major and referable schemes, further documents join the energy statement: a whole-life-carbon assessment, which quantifies not just operational carbon but the embodied carbon in the materials, construction, maintenance and eventual demolition of the building, reported in the GLA's whole-life-carbon spreadsheet; and a circular economy statement, which addresses how materials are sourced, reused and kept out of waste. An overheating analysis (CIBSE TM59/TM52) supports the cooling-hierarchy case, and a drainage and SuDS strategy addresses surface water. Each of these interacts with the energy strategy — a timber structure, for instance, cuts embodied carbon in the whole-life assessment while a heat pump cuts operational carbon in the energy statement.

The practical point is that these documents form a system, and their value is in their coherence. An application where the energy statement, the sustainability statement, the drawings and the specification all tell one consistent story is far more likely to be validated quickly and approved than a set of separately authored reports that contradict each other. Because we coordinate the architecture and the supporting documents together, that coherence is built in — the energy statement is not a standalone report but a load-bearing part of a single, consistent application.

Understanding why energy statements go wrong is the best way to make sure yours does not, and the failures cluster into a few recognisable themes. The most common is skipping or under-doing 'be lean': a statement that leans on renewables and offset while providing only a token fabric strategy fails the fundamental test of the hierarchy, and — for residential majors — the specific requirement for a minimum carbon saving from efficiency alone. Southwark, like the GLA, wants to see that demand was driven down first, and a weak be-lean section is a reliable way to attract a request for further information.

The second theme is inconsistency between the energy statement and the rest of the application. If the PV modelled in the calculation does not match the roof plan, if the glazing on the drawings is more generous than the model assumes, or if the specified heating system differs from the one in the strategy, the assessor cannot rely on the numbers, and the statement stalls. This is almost always the product of the energy work being done separately from the design, and it is precisely the failure that integrated design prevents.

The third theme is technical error in the baseline and reporting: using the wrong Part L edition (the 2013 baseline instead of the required 2021 one), a mis-specified notional building, or failing to append the GLA carbon emission reporting spreadsheet in the correct format on a major scheme. Because every reduction figure depends on the baseline, an error here undermines the whole statement, and it is a frequent cause of validation delay. Over-reliance on offset is a related failing — treating the carbon offset payment as the strategy rather than the last resort, which reads to the council as a scheme that simply has not done the on-site work.

Finally, statements come unstuck on the companion issues: an inadequate or absent overheating analysis where Policy P69 requires one, no proper investigation of heat-network connection in a priority area, or a missing 'be seen' commitment on a major scheme. Our approach is to anticipate every one of these — a rigorous be-lean strategy, a statement fully consistent with the drawings, the correct baseline and reporting format, offset treated as a genuine last resort, and the overheating, heat-network and monitoring points all addressed — so the energy statement supports the application rather than holding it up.

The cost of preparing an energy statement in Southwark depends chiefly on the scale and type of the development and the level of supporting analysis required. A proportionate energy or sustainability statement for a small scheme — a new house, a few flats, a change of use — is a modest, self-contained piece of work. A full energy statement for a major scheme, with SAP or SBEM modelling, the GLA reporting spreadsheet, an overheating analysis and, on referable schemes, whole-life-carbon and circular-economy companions, is a larger undertaking. We scope the work to your specific project and give you a clear, fixed fee for our part before any work begins, so you know the cost at the outset.

Set against our fee, there are other costs to budget for. The council's planning application fee is set nationally and payable to Southwark on submission; pre-application advice, if used, carries its own fee; and — most significantly on a major scheme — the carbon offset payment, if the scheme cannot reach its on-site target, is a real and potentially large cost calculated at £95 per tonne of residual carbon over 30 years. The single best way to control that offset cost is a rigorous on-site strategy, which is exactly what a well-prepared energy statement delivers: every tonne saved on site is a tonne you do not pay to offset.

It is worth framing the energy statement as an investment rather than a cost. A weak statement that attracts rounds of queries, or that under-delivers on-site carbon and inflates the offset bill, costs far more in time and money than a rigorous one prepared properly at the start. And because the energy strategy shapes the building — its fabric, heating and renewables — getting it right early avoids the expensive redesign that follows when a scheme is bounced for an inadequate energy case or when the modelled performance cannot actually be built.

On timescales, a proportionate energy statement for a minor scheme is usually a matter of a couple of weeks once the design is developed enough to model; a full major-scheme energy statement takes longer and runs in parallel with the design and the other sustainability documents. The application itself is determined against Southwark's targets — around eight weeks for a minor application and thirteen for a major — though complex or referable schemes can take longer. We give you a realistic programme for your specific project at the outset so you can plan around it.

The process starts with feasibility. We assess the site, confirm its planning context — conservation area, heritage, Heat Network Priority Area status, constraints — and establish what the scheme can realistically deliver and what the energy and sustainability requirements will be. Crucially, we begin the energy strategy at this stage, alongside the first design sketches, so the low-carbon logic drives the building's form rather than being retrofitted later. This is where we give you an honest early view of the on-site carbon reduction achievable and any likely offset exposure, before you commit to a full application.

Southwark offers pre-application advice, and on a major or sensitive scheme it is frequently worthwhile. The borough's sustainability requirements are demanding, and a written steer from the council — on the energy strategy, the offset position, heat-network expectations and overheating — reduces the risk of a refusal, flags concerns early while the design can still respond, and shows the case officer that the scheme has been developed thoughtfully. We prepare and manage the pre-application submission where it adds value, which on a prominent or major scheme is usually the case.

We then prepare the full drawing package and supporting documents — including the energy statement, and on major schemes the accompanying sustainability suite — and submit the application to Southwark through the Planning Portal, managing it through validation and determination. That means confirming the energy statement meets the current validation checklist so it is accepted first time, responding to the case officer's queries, providing further information where asked, and negotiating amendments where that secures approval. A minor application runs against an eight-week target from validation; a major application against thirteen weeks.

Once permission is granted, the energy commitments carry through into the Building Regulations and construction stage, where the same coordinated team prepares the technical information and the Part L compliance (with SAP or SBEM calculations) that satisfy building control and match the planning energy statement. On schemes with a 'be seen' commitment or energy-related planning conditions, we help discharge them and set up the monitoring. Because an energy statement lives or dies on the building actually delivering the promised performance, this continuity from planning through building control to construction is not a luxury — it is how the carbon savings promised at planning are the carbon savings that get built.

To make the process concrete, consider a common Southwark scenario: a small infill site on a residential street near Peckham, where an owner wants to build a modest block of new flats. The scheme sits just below the major-development threshold, so it does not need the full referable suite, but Southwark's Policies P69 and P70 still apply and the application needs a focused energy statement demonstrating compliance. The plot is tight and overlooked, and the roof area available for renewables is limited — a realistic, everyday Southwark project rather than a landmark tower.

At feasibility we survey the site, confirm it is not in a heritage designation that would constrain the roof, check its Heat Network Priority Area status, and begin the energy strategy alongside the first sketches. We design a compact, well-oriented form with a fabric-first envelope — high insulation, good airtightness, high-performance glazing and controlled ventilation — that drives the heating demand right down and satisfies the 'be lean' stage, including the fabric-only carbon saving the London Plan looks for. The glazing and orientation are tuned to bring in daylight while controlling summer solar gain, so the same design that cuts carbon also manages overheating.

The strategy then works down the hierarchy. 'Be clean': we establish that no viable heat-network connection is available at the site, so the scheme is designed around an efficient, all-electric approach. 'Be green': each flat is served by an air-source heat pump for heating and hot water, and roof-mounted solar PV is maximised for the available roof area, with the panels designed into the roof form from the start rather than added later. We build the SAP model against the Part L 2021 baseline, quantify the reduction at each stage, and report the total on-site carbon reduction — pushing it as close to the target as the site allows to minimise any residual.

The energy statement pulls this together: the baseline, the be-lean, be-clean and be-green reductions in order, the total on-site saving, any residual carbon and the corresponding offset contribution at £95 per tonne over 30 years, plus a TM59 overheating analysis satisfying Policy P69's cooling hierarchy. It is submitted alongside a set of drawings whose glazing, roof PV and plant locations match the model exactly, so the numbers and the drawings agree. Managed through Southwark's validation and determination against the minor-application target, a scheme prepared this way goes in as a proposal the case officer can support — a genuinely low-carbon building with an energy statement that stands up to scrutiny. That is the difference between an energy statement designed to pass and one merely hoped through.

A grant of planning permission on a scheme with an energy statement usually comes with conditions and, on majors, obligations that carry the energy commitments into delivery. It is worth knowing what to expect so they can be discharged smoothly rather than becoming a stumbling block, because a condition left undischarged can jeopardise the lawful implementation of the scheme.

Common energy-related conditions require the submission and approval of final energy and sustainability details before construction, the installation and retention of the renewable-energy and low-carbon-heating systems shown in the approved energy statement, and, on qualifying schemes, evidence that the building achieves the promised performance — reflecting the 'be seen' direction towards verified, measured outcomes. Overheating mitigation and the cooling-hierarchy measures may also be conditioned, as may the details of the PV array and the heat-pump plant, including its acoustic performance.

On major schemes, the carbon offset payment is secured through a Section 106 legal agreement, calculated on the residual carbon in the approved energy statement at £95 per tonne over 30 years. Because the sum flows directly from the energy statement's on-site reduction, the rigour of that statement has a direct financial consequence, and it is another reason to maximise the on-site strategy rather than defaulting to a large offset. Any 'be seen' monitoring commitment is also typically secured and has to be set up and reported after occupation.

The practical message is that permission is the beginning of a low-carbon building, not the whole of it: the conditions, the Building Regulations Part L sign-off, the Section 106 offset and any 'be seen' reporting all have to line up with what the energy statement promised. Because we design the scheme and prepare the energy statement with these downstream obligations in mind, the conditions Southwark attaches are generally ones the scheme already satisfies — which makes discharging them straightforward and keeps the carbon performance intact from design through to the occupied building.

Crown Architecture prepares energy statements and low-carbon designs across Southwark and the surrounding boroughs, and we do it as a single coordinated service: the architecture, the design, and the energy and sustainability strategy under one roof. That integration matters more on the energy case than on almost any other document, because the carbon savings depend on the building's fabric, form, heating and renewables — and if the energy work is done separately from the design, the statement and the drawings drift apart and the strategy underperforms. Designed together from the first sketch, they resolve into a scheme that is genuinely low-carbon, buildable and consistent from front page to appendix.

We know the Southwark regime: Policies P69 and P70 of the Southwark Plan 2022, the Climate and Environment SPD, the London Plan energy hierarchy and offset, the £95-per-tonne carbon offset fund, and the GLA reporting conventions and Part L 2021 baseline that a compliant statement now has to use. We use that knowledge to work down the hierarchy properly — a rigorous be-lean fabric strategy, a genuine heat-network investigation, maximised on-site renewables — so the statement demonstrates real on-site carbon reduction and minimises any offset, and so the sustainability case is a strength of the application rather than its weak point.

Just as importantly, we are straightforward to work with. We tell you honestly at feasibility what on-site reduction your scheme can achieve and what offset exposure to expect; we quote a clear fixed fee; and we prepare an energy statement that is fully consistent with the drawings, so a case officer can rely on the numbers without filling in gaps. We right-size the document to the scheme — a focused statement for a minor scheme, the full suite for a major or referable one — so you pay for the rigour the application needs and no more.

We also stay with the project after the statement is written. We manage the application through Southwark's validation and determination, respond to the case officer, help discharge energy-related conditions, carry the strategy into the Building Regulations Part L compliance, and set up any 'be seen' monitoring — so the carbon savings promised at planning are the ones actually delivered on site. The aim is a single, accountable point of contact from the first survey to a finished, low-carbon building, rather than a report handed over and a client left to reconcile the drawings, the energy consultant and the council alone.

If you are planning a development in Southwark that needs an energy statement — a new home, a small block, a change of use or a major scheme — send us the address and what you have in mind, and we will tell you honestly what the energy case requires, what it will cost, and how to get there.