Planning
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Do I need
planning permission?

We can tell you in 23 seconds.

Free to use · no signup required

Get my free planning check

Results built from 20.6 million UK planning applications.

Full planning applications

Drawings in 2 weeks. Submitted in 3. The council decides in 8.

That is the whole journey if your check looks good: £1,880 all-in, fixed. Refused? We redesign and resubmit free. Compare what's included

Answer three questions - your address checked against planning records, constraints and local policy. Free.

Example report6m rear extension - 1930s semi, Barnet N12

No planning permission needed

You notify the council instead. At 6m this clears the 3m automatic limit, so it takes the faster prior-approval route - decided in 42 days

91%

of similar rear extensions within 1km approved (34 decided)

Your limit6m deep, 4m high
Constraints10 of 10 passed
Open the full report

One for every project type

What the free check tells you

1

Do you need planning permission?

Permitted development, prior approval or a full application - decided by the GPDO rules for your property type

2

How often your council approves it

The real approval rate for your project type within 1km, from 2,589,298 analysed decisions - plus the nearest approved scheme to your address

3

How far you can build

Your exact depth, height and eaves limits in metres, and what an Article 4 direction or conservation area changes

4

What it will cost

Build cost for your area and project type, and the £1,880 all-in fee if you want us to do the drawings

Recent projects

33 live now

Loft conversion

In progress

Rear dormer with en-suite - Walthamstow, E17

Permitted Development
Build cost£58,000
Our fee£1,880

Rear extension

Contract sent

4m single storey with roof lantern - Tooting, SW17

Permitted Development
Build cost£54,000
Our fee£1,880

Side return extension

In progress

2.1m x 6.5m with skylights - Leyton, E10

Permitted Development
Build cost£46,000
Our fee£1,880

Two storey extension

Submitted

Rear 3m over two floors - Croydon, CR2

Planning Permission
Build cost£96,000
Our fee£1,880

Homeowner projects £1,880 all-in · new builds and multi-unit schemes from £4,500

Includes drawings, application and submission

Mayfair Studio is a UK architecture practice specialising in planning approvals.

20.6mUK applications on file
420planning authorities covered
33projects live right now

Before you spend anything, you can see the approval rate for your project type near your address, drawn from 2,589,298 analysed decisions. You only pay when you're ready to proceed.

Why homeowners choose us

Fixed-price drawings and planning services that save you time and money.

Start in days, not weeks

No survey appointment needed to begin - we design from planning records, property data and your photos.

Designs in 2 weeks

First draft drawings delivered within 14 days of instruction.

Unlimited changes

We revise until you're happy. No extra charges, no compromise on your design.

Engineering included

Structural calculations are in the fixed fee. No separate engineer's bill.

Complete drawing set

Planning, building regulations and builder-ready drawings - all in one package.

Full planning support

We prepare, submit and manage your application. No paperwork, no planning stress.

Fixed prices. No surprises.

Traditional architects charge £3,000-£8,000. Ours is £1,880, all-in.

PackagePrice

Homeowner projects

Loft conversion, rear/side/wrap-around extension, or two-storey extension

£1,880

New builds and multi-unit schemes

New build houses and flats, conversions and change of use

£4,500 + £1,200/unit

Basements, listed buildings and complex sites

Anything that needs a bespoke scope

From £2,495

Refused? We redesign and resubmit free.

Every package includes unlimited revisions, council liaison, free amendments if the council asks for changes, and a free resubmission if your application is refused.

Start with the free planning check

If your project fits the standard package, the price is £1,880 - no quote needed

What we draw

Loft conversions, extensions, building regs and planning drawings - one £1,880 fee, unlimited revisions.

Loft conversion drawings

Dormer, hip-to-gable, L-shaped and mansard designs that maximise headroom and light. Structural calculations included.

Loft drawings

House extension drawings

Rear, side return, wrap-around and two-storey extensions. Builder-ready plans that blend with your existing home.

Extension drawings

Building regulation drawings

Complete technical drawings and calculations for building control approval. Exact specifications your builder can price and build from.

See pricing

Planning permission drawings

Full application prepared, submitted and managed for you, with council queries and amendments handled free of charge.

See pricing

Buying a property rather than extending one?

The Pro report answers what you can build on a site before you bid or exchange: the planning history, the constraints, what has been approved nearby and what the numbers look like. £395, back within 24 hours.

See what a Pro report covers

How it works

From first check to ready-to-build drawings, typically 3 to 6 months.

Phase 1 · Months 1–3

Planning and approvals

Existing drawings - from records and photos1 week
Proposed design1–2 weeks
Planning submission and liaison8–10 weeks

Phase 2 · Months 4–6

Building regulations

Measured survey(Included)1 week
Building regs drawings3–4 weeks
Structural calculations(Included)10–12 days
Party wall notices(Included)1–2 weeks
Builder introductions4–6 weeks
Frequently asked questions

Everything you need to know

Do I need planning permission for my extension?
It depends on your property type, location and the size of the extension. Most single storey rear extensions up to 3m (terrace/semi) or 4m (detached) fall under Permitted Development, meaning no planning application is needed. But conservation areas, Article 4 directions and flats have stricter rules. The free planning check gives you a definitive answer in about 2 minutes.
How much does an extension cost in London in 2026?
Single storey rear extensions in London cost around £2,200–£3,200 per m² for build, plus a fixed £1,880 all-in for architectural drawings and planning support. A typical 20m² extension totals £45,000–£65,000 including VAT. Prime central London (Kensington, Chelsea, Westminster) runs 20–30% higher.
How much do you charge?
£1,880 all-in, fixed, for a standard loft conversion or extension - covers survey, drawings and planning support. Paid in two stages: £1,180 through to planning submission, £700 for building regs and structural calcs once approved. £2,495+ is for listed buildings, basements and new builds. Council application fees are paid direct to the council on top of our fee.
How long does planning permission take?
A Full Planning application takes 8 weeks from validation (statutory target). Prior Approval is faster at 6 weeks. Permitted Development does not need an application at all if you are eligible. Add 2–3 weeks for us to prepare drawings before submission.
Is the planning check really free?
Yes. No sign-up, no email, no payment required. You get the full report including PD eligibility, planning constraints (conservation area, Article 4, listed building, flood risk, TPOs), borough policy summary and recommended route. We only charge if you decide to appoint us to produce the drawings.
What is the difference between Permitted Development and Planning Permission?
Permitted Development (PD) is a set of national rules that let you extend without a planning application, as long as you stay within strict size and design limits. Planning Permission is a full application to the council, required when you exceed PD limits or your property has Article 4 restrictions. PD is faster and cheaper but more limited.
Do you work outside London?
Yes. Our AI planning checker covers all English local planning authorities using national planning datasets. For architectural drawings we work across London and the Home Counties (Surrey, Kent, Essex, Hertfordshire, Buckinghamshire). Further afield we handle it as a remote project with a paid site visit.
What happens after I submit my planning check?
You get the full report instantly, on screen, with no email gate. If you decide you want us to produce drawings we follow up within 2 hours during business hours to confirm scope, collect existing drawings or arrange a measured survey, and send you a fixed-fee quote. You do not pay until you sign.

Still have questions? Email us or start a free planning check.

Ready to check your property?

Start with the free planning check. If your project fits the standard package, the price is £1,880 all-in - no quote needed.

Get my free planning check

Prefer to speak to someone?

hello@mayfairstudio.co.uk
07942 343 800
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