How Much Do Planning Drawings Cost in London? (2026)

How much do planning drawings cost in London in 2026?

For a typical London home, expect a permitted development or Lawful Development Certificate pack from around £950, a full householder planning set from around £1,600, and a complete planning-plus-building-regs package with structural calculations from around £2,200. The table below breaks this down. These are drawing and preparation fees only — the local authority charges its own statutory application fee separately, and that goes directly to the council through the Planning Portal.

The reason the ranges are bands rather than single figures is that no two London houses are the same. A flat-roofed rear extension on a post-war semi with a simple layout sits at the bottom of its band; a two-storey side-and-rear extension on a Victorian terrace, with a hipped roof, a party wall on each side and a conservation-area design statement, sits at the top. When you receive a quote, the honest question is not whether it is cheap but whether it covers the same scope as the others you are comparing — because a £600 quote almost always omits the survey, the statements, or the building-regulations stage that a £1,600 quote includes.

What drives the cost of planning drawings?

Three things move the price most: the application route, whether structural calculations are needed, and site complexity. A Lawful Development Certificate is evidence-based and needs a lean set of drawings proving the works stay within permitted-development limits, so it is the cheapest route. A full householder application is judgement-based — an officer decides whether the design is acceptable — so it needs more persuasive drawings and usually a written statement, which lifts the fee.

Structural work is the next lever. If your project removes a wall, adds a steel beam, or builds a new roof, a structural engineer must design and calculate those elements, and the building-regulations drawings must show them. That is why a complete package costs more than planning drawings alone. Finally, site complexity — a conservation area, a listed building, a basement, a sloping or constrained plot, or a party wall shared with neighbours on both sides — each adds drawing time and evidence, because the council and the regulations demand more detail before they will approve.

• Application route — a Lawful Development Certificate costs less to prepare than a full planning application with a design statement
• Structural calculations — adding steelwork and foundation design increases scope
• Complexity — conservation areas, listed buildings, basements and party-wall situations add drawing and evidence work
• Survey — an accurate laser survey is included in our fees but is where cheaper providers cut corners
• Revisions — councils frequently request changes, which a fixed fee absorbs but an hourly rate bills

What exactly is included in a set of planning drawings?

A common surprise is how much sits behind the phrase planning drawings — it is never a single sheet. A proper submission is a coordinated set that lets a planning officer understand the existing building, the proposal, and the change between them at a glance. Skimping on any part is the most common reason an application is validated late or refused outright, so it is worth knowing what a complete pack actually contains before you compare quotes on price alone.

The set falls into two halves: the drawings themselves, and the written documents that argue the planning case. A quote that includes both is doing the full job; a quote that hands you drawings and leaves you to write your own Design and Access Statement is quietly cheaper because it is quietly incomplete.

Do the drawings also cover building regulations?

This is where many homeowners are caught out, because planning permission and building-regulations approval are two entirely separate consents. Planning drawings show what the extension will look like and where it sits; building-regulations drawings show how it is actually constructed — the foundation depth, the insulation build-up, the steel sizes, the fire strategy and the drainage. A planning-only package will get you a decision from the planning officer, but you cannot legally build from it, because building control will not sign off construction it has never seen documented.

That is why the complete package in the table costs more: it carries both stages plus the structural calculations that underpin them. Buying the two stages together is usually cheaper than buying them apart, because the survey is done once and the building-regs set builds directly on the approved planning drawings. If a quote covers only planning, budget separately for the building-regulations drawings and structural design before you start on site.

Is a fixed fee better than hourly for planning drawings?

For homeowners, a fixed fee is almost always better. It caps your cost, aligns the drawer's incentives with getting the application right first time, and means the revisions a council often requests do not become extra invoices. Hourly billing quietly rewards slow work and every officer query, whereas a fixed fee puts the risk of revisions on the practice, not on you. Planning is an iterative process — it is normal for an officer to ask for a lower ridge, an obscure-glazed window or a materials change before approving — and under an hourly arrangement each of those requests is a fresh charge.

A fixed fee also makes the whole project easier to budget, because the drawing cost is a known number from day one and does not drift as the design develops. That certainty matters most on exactly the projects where hourly billing balloons — conservation areas, party-wall sites and anything the planners scrutinise closely. Every DrawingsDirect quote is fixed and includes free redraws to approval, so a request for minor changes from the planning officer never lands as a surprise bill, and you know the full drawing cost before you commit.