WhatCanIBuild
Cost guide

How much is planning permission?

The short answer: £548 for the application itself. The real answer, including everything you actually have to pay between “I want to extend my kitchen” and “I have approved plans”, is usually £3,000 to £8,000. This guide breaks down every fee and every professional, and explains the one cost most homeowners don’t budget for: the cost of getting it wrong.

WBWhatCanIBuild5 min readVerified Summer 2026
£548
householder app fee
£3k–8k
typical all-in
£0
if it’s permitted dev
£274
LDC (proposed)
The statutory fees you pay the councilProfessional fees you’ll probably also payThe hidden cost: getting refusedFind out your approval probability before you spend £5,000Questions
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The statutory fees you pay the council

Householder planning application

Extensions, loft conversions, porches, external alterations to a single home

£548

Lawful Development Certificate (proposed)

Legal confirmation that your permitted development project is lawful, before you build

£274

Lawful Development Certificate (existing)

Retrospective confirmation that already-built work was lawful (for sale / mortgage purposes)

£548

Prior Approval (larger rear extension)

Single-storey rear extensions 4–8m on detached / 3–6m on other houses under the “larger home extension” scheme

£120

Pre-application advice

Varies dramatically by council. Non-binding opinion on a proposal before you apply.

£50–£500

Appeal to Planning Inspectorate

No official fee, but the appeal itself requires professional input usually costing £2,000–£10,000

£0

Professional fees you’ll probably also pay

The £548 statutory fee is the cheapest part of the process. The real spending happens before you submit.

Architect or architectural technician — £1,500–£5,000

Planning drawings (site plan, floor plans, elevations) and typically building regulations drawings. A draughtsperson or architectural technician is usually enough for straightforward extensions. A full RIBA architect costs more but brings stronger design skills and is worth it in conservation areas.

Structural engineer — £500–£1,500

Structural calculations for any openings in existing walls (e.g. removing a rear wall for an open-plan extension) and for foundation design. Required by Building Regulations even if not formally submitted with planning.

Party wall surveyor — £700–£1,500 per neighbour

Required by the Party Wall Act 1996 if your work is within 3 metres of a shared wall or boundary. Each affected neighbour can appoint their own surveyor at your cost. Common for terraced, semi-detached, and end-of-terrace properties.

Planning consultant (optional) — £500–£3,000

For complex cases: listed buildings, conservation areas with restrictive design guidance, proposals that need a planning statement or a design & access statement, or any project where the council has refused an earlier application. Not needed for simple extensions.

Building Regulations fees — £600–£1,200

Separate from planning permission. Required for almost all building work regardless of whether planning permission is needed. Covers plan checks and construction inspections by the council’s Building Control team or an Approved Inspector.

The hidden cost: getting refused

A refused planning application doesn’t just lose you the £548 fee. It also loses you most of the architect fees you paid to design the refused proposal, the time spent on preparation, and months of delay. A typical refused householder application costs the homeowner £3,000–£6,000 before they get back to square one.

That’s why, for borderline projects or properties on constrained sites (conservation areas, listed adjacency, flood zones, tight boundaries, contested design context), the single highest-ROI £9 you can spend before committing to a design is knowing what your actual odds look like based on real recent decisions nearby.

Find out your approval probability before you spend £5,000

Get your odds — £9. Our £9 Full Report gives you a personalised approval probability for your specific property and project, the 5 nearest comparable decisions from real recent applications, the most common refusal reasons at your council for your project type, and a concrete action plan. Before you pay the architect. Delivered as a PDF.

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Frequently asked questions

The statutory householder application fee is currently £548 for alterations or extensions to a single dwellinghouse. That’s the fee you pay the council when you submit the application. On top of that, most homeowners also pay for an architect or designer (£1,500–£5,000 typical), a structural engineer if needed (£500–£1,500), and possibly a party wall surveyor (£700–£1,500 per affected neighbour). Total out-of-pocket is usually £3,000–£8,000 by the time you submit.

As of 1 April 2026, the householder planning application fee in England is £548 (it was £258 before annual indexation took effect). Outline applications, full applications for new dwellings, commercial development, and change of use all have different fees (often substantially higher). The householder rate covers most extension, loft conversion, and external alteration applications at a single home.

Yes, for some projects. A Lawful Development Certificate (LDC) for proposed use costs £274 — half the full planning fee — and is the right route if your project is already permitted development and you just want legal confirmation. Prior Approval applications for larger rear extensions (the “larger home extension scheme”) cost £120 and are faster than full planning.

For a typical single-storey rear extension, expect £1,500–£3,500 for a draughtsperson or architectural technician preparing planning drawings + building regulations drawings. A full architect (RIBA-qualified) typically charges £3,000–£8,000 for the same scope, and usually a percentage of construction cost (5–15%) if they stay involved through the build. For loft conversions and more complex projects, fees scale up.

You lose the £548 application fee and usually most of the architect fees (unless the architect agrees to redesign at reduced rates). You can appeal to the Planning Inspectorate within 6 months, but appeals are expensive (£0 in official fees, but legal and consultancy costs often £2,000–£10,000) and often unsuccessful. The more common route is to redesign and resubmit — a second application within 12 months on the same site is free, but you still pay your designer again.

Pre-application advice fees vary dramatically by council. Typical range for a householder query: £50–£300 for a written response, £200–£500 for a meeting with a planning officer. Some councils offer free initial advice for very small queries. For borderline projects in conservation areas or on constrained sites, pre-app advice is usually worth the money — a £250 pre-app that tells you the council would refuse your design can save you the full £548 application fee plus thousands in wasted architect time.

Not sure if you need planning permission at all?

Half the homeowners who think they need planning permission actually don’t — their project is permitted development and they just need a £274 Lawful Development Certificate, or nothing at all. Check your project in 2 minutes, free.

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