Free cost calculators
Instant estimates for the most common London projects. Borough-specific.
Instant estimates for the most common London projects. Borough-specific.
The statutory fees, which are the only fixed numbers in any London project: £548 for a householder application, £274 for a lawful development certificate and £249 for larger-extension prior approval. Everything the calculators return is a range. A resubmission within twelve months of a decision on the same site is normally free once.
| Item | Amount | Basis |
|---|---|---|
| Householder planning application | £548 | statutory, England 2026 |
| Lawful development certificate | £274 | statutory |
| Larger home extension prior approval | £249 | statutory |
| Full application, one new dwelling | £610 | statutory |
| Listed building consent | no fee | statutory |
| Planning drawing set | from £1,225 | our fixed fee |
| Building regulations set | from £840 | our fixed fee |
Sources: the Town and Country Planning (Fees for Applications, Deemed Applications, Requests and Site Visits) (England) Regulations 2012, as amended, 2026 rates, retrieved 1 September 2026; our own published fixed fees. Build costs the calculators return are our 2026 London range and are estimates, not published statistics.
Only the fees paid to the council and to us. A householder application costs £548 whatever the borough decides, a certificate of lawfulness £274, and the larger home extension prior approval £249. Our drawing packages start at £840 and a measured survey at £245. Everything past that — the build itself — is an estimate until a builder has stood in the room, and no calculator on this page pretends otherwise.
Access, mostly. A terrace with no side return means every cubic metre of spoil and every brick moves through the house, and that is labour rather than material. Then the ground: a shallow Victorian footing next to a neighbour's wall usually means underpinning and a party wall award. A calculator that asks only for floor area cannot see any of it, which is why its answer is a starting range and not a quote.
It changes the risk more than the price. Across London 83.0% of the 77,680 householder applications decided in the three years to March 2026 were approved, and 97.0% of all decisions were made by a case officer rather than a committee. Staying inside permitted development — 3 metres deep on a terrace or semi, 4 on a detached house — avoids the application entirely, and a £274 certificate then documents that you were entitled to it.
As soon as a number has to be committed to. Every calculator here works from the dimensions you type, and those are usually taken from a deed plan or a memory of the room. A measured survey replaces both with the building as it stands, which is what the drawings, the structural calculations and the builder's price all have to agree with. It is the cheapest point at which to find out the house is not the shape you thought.
