Planning Drawings vs Building Regulation Drawings: What's the Difference?

Planning drawings are the documents you submit to your local planning authority (LPA) to apply for planning permission or lawful development certificate. They show the planning authority what you intend to build, how it relates to the existing building and the surrounding context, and what it will look like from the street, from the garden, and from neighbouring properties.

The planning authority uses your drawings to assess the proposal against national planning policy (the NPPF) and the council's local plan policies. The main questions are: Does this fit the character of the area? Does it harm the amenity of neighbours? Does it respect any heritage designations? Is it the right scale for the plot? Planning drawings must answer these questions visually and in the supporting documents.

Planning drawings are not construction documents. They do not show how the building is held up, what insulation is used, how drainage runs, or what materials are specified in technical detail. They show outline dimensions, external appearance, and site context — the information a planning officer needs to make a planning decision.

• Site location plan (OS-based, 1:1250 scale, boundary marked in red)
• Block plan showing the site and immediate surroundings (1:500)
• Existing floor plans — all floors of the current building
• Proposed floor plans — showing what changes are proposed
• Existing elevations — all affected sides of the existing building
• Proposed elevations — showing how external faces will look after the works
• Section drawings where required
• Design and access statement (required for conservation area applications and some listed building applications)

Building regulation drawings (also called building control drawings or technical drawings) are the documents you submit to building control — either your council's building control department or a registered building control approver (private-sector alternative) — to demonstrate that the proposed works comply with the Building Regulations.

The Building Regulations are a set of technical standards covering structure (Part A), fire safety (Part B), damp and weathering (Part C), drainage (Part H), ventilation (Part F), energy efficiency (Part L), accessibility (Part M), and other aspects of building performance. A building regulation drawing package must demonstrate compliance with all relevant Parts.

Unlike planning drawings, building regulation drawings are genuinely technical documents — construction drawings, not design proposals. They show beam and lintel sizes, foundation type and depth, insulation specification with U-value calculations, fire-rating of walls and floors, drainage routes and gradients, ventilation openings, and structural connections. A structural engineer's calculations are typically coordinated alongside the drawings.

Building control inspectors use these documents to assess the technical submission before work starts (full-plans application) and then to guide inspections during the works. At the end of the project, a Completion Certificate is issued, which is essential for conveyancing and mortgage purposes.

The simplest way to understand the difference is this: planning drawings are for the planning system, building regulation drawings are for the building system. They are two separate legal requirements, assessed by different people, at different stages of the project.

Planning comes first. You need planning permission (or permitted development confirmation) before building regulation approval is generally sought, though in practice both processes are often run in parallel for longer projects.

Planning drawings focus on external appearance, character, and planning policy compliance. Building regulation drawings focus on structural safety, thermal performance, fire escape, drainage, and building performance compliance.

For most extensions, loft conversions, and structural alterations in London and the home counties, you will need both planning drawings and building regulation drawings — they are sequential but overlapping requirements.

The typical project sequence is: (1) prepare planning drawings → (2) submit planning application → (3) planning permission granted → (4) prepare building regulation drawings → (5) submit to building control → (6) building control approval → (7) start works → (8) inspections during works → (9) Completion Certificate.

In practice, building regulation drawings can be prepared and submitted before planning permission is granted. Running them in parallel reduces the overall programme, particularly where the project needs to start quickly. Formal full-plans approval should not be issued before planning permission, but submission can overlap.

Some works require building regulation approval but not planning permission — for example, a loft conversion within permitted development limits. In these cases, you still need a building regulation drawing package and approval even though no planning application is required.

No — planning drawings and building regulation drawings are not interchangeable. Planning drawings lack the technical detail required for building control. Building regulation drawings contain significantly more technical content than a planning application requires.

Some architects and designers prepare 'hybrid' drawing packages that are at a level of detail between the two, but in practice this is rarely satisfactory for either purpose. Planning officers want clean presentation drawings; building control needs accurate technical specification.

The best approach is a coordinated package where the planning drawings establish the approved design, and the building regulation drawings develop that design in full technical detail. Crown Architecture prepares both as coordinated sets — the building regulation package extends and develops the planning set rather than redrawing from scratch.

Planning drawing fees and building regulation drawing fees are typically separate line items in a professional fee proposal. Combined planning and building regulation packages for a typical London extension range from £2,500 to £5,000 depending on scale and complexity.

Planning drawings are generally less expensive to prepare than building regulation drawings because they contain less technical content. A planning-only package for a single-storey rear extension might range from £1,200 to £2,000; the building regulation package adds £1,000 to £2,500 depending on structural complexity.

Timescales: planning drawings typically take two to three weeks to prepare from measured survey; building regulation drawings three to five weeks, depending on the structural engineering input required.

The most common mistake is assuming that obtaining planning permission means you can start work. Planning permission grants the right to develop — it does not confirm that the construction meets Building Regulations. Building regulation approval is always needed separately.

Equally common is the reverse: starting with building regulation drawings before planning permission has been obtained, then having to substantially redesign after the planning decision. Preparing planning drawings first, obtaining permission, and then developing the building regulation package in detail avoids this wasted work.

For conservation area and listed building projects, a third document — a heritage statement or design and access statement — is often required for the planning application. This is neither a planning drawing nor a building regulation drawing, but a written assessment accompanying the planning submission.