Mortlake, Greater London
Rear extension planning drawings in Mortlake
We plan and build rear extensions for homeowners in Mortlake. Measured survey, design options, planning drawings and the application, handled for you. Start with a free site visit, then a written price once the design is agreed.
Mortlake is covered from our Greater London round, including SW13, SW14 and TW9. For Mortlake homes we start with a measured survey, then draw options before anything is submitted.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
What do rear extension planning drawings cost in Mortlake?
As a guide, £1,000–£2,500 including VAT for a single-storey rear extension, or £2,000–£3,500 for a two-storey scheme. A householder planning application in England costs £548 (£575 for applications made from 8 December 2026), and a lawful development certificate for proposed work costs half the householder fee. Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission for a rear extension in Mortlake?
Whether your rear extension in Mortlake needs a planning application depends on its size, your house and any local restrictions.
A two-storey rear extension can be permitted development in England only if it projects no more than 3 metres, stays at least 7 metres from the rear boundary, matches the existing roof pitch and has obscure-glazed upper side windows. In practice most double-storey rear extensions go through a householder planning application.
Councils aim to decide householder applications within 8 weeks of validation, and prior approval within 42 days.
Conservation areas, National Parks, National Landscapes and the Broads restrict permitted development, and listed buildings always need listed building consent. Before any drawing we look up the property's history with the council, because earlier extensions and removed rights change the answer.
What are homes in Mortlake like to extend?
Much of Mortlake is Victorian and Edwardian terraced housing with narrow back additions, which suits side returns, wraparounds and 3 metre rear extensions. Many streets are in conservation areas, gardens are short, and almost everything comes through the house or along a rear alley.
How a rear extension in Mortlake comes together
Free site visit
We measure the house and garden, look at the back wall, drainage and boundaries, and talk through what you want from the space.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Planning and regulations
We take the design through the right planning route, then produce the construction drawings and engineer's calculations for building control.
Build and sign-off
We build to the approved drawings with regular updates, then hand over the building control completion certificate and any guarantees from suppliers.
Rear extension planning drawings near Mortlake
Close by, we work in East Sheen, about 0.5 miles away, and Barnes, about 0.9 miles away.
- Rear extension planning drawings in East Sheen
- Rear extension planning drawings in Barnes
- Rear extension planning drawings in Kew
- Rear extension planning drawings in Roehampton
- Rear extension planning drawings in Chiswick
Other work in Mortlake:
FAQ
Rear extension planning drawings questions in Mortlake
Do I need a party wall agreement?
In England, usually yes if the extension is on or near a shared boundary or the foundations are close to a neighbour's building. We serve the notices.
Do I need planning permission for a rear extension in Mortlake?
Often not for a single-storey rear extension of up to 3 metres (4 metres on a detached house) under permitted development, or up to 6 or 8 metres with prior approval, unless the house is in a conservation area or its rights have been removed.
Do I need an architect?
You need accurate drawings by someone who knows householder planning; we provide them.
How long does a rear extension take to build in Mortlake?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
Do you handle building control in Mortlake?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Is the site visit in Mortlake free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.