Horsham, West Sussex
Rear extension planning drawings in Horsham
Rear extension planning drawings in Horsham: measured survey, design options, planning drawings and the application, handled for you. We measure the house, show you what the rules allow, price it in writing and build it.
Horsham is covered from our West Sussex round, including RH12. For Horsham 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 Horsham?
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. These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission for a rear extension in Horsham?
Whether your rear extension in Horsham needs a planning application depends on its size, your house and any local restrictions.
England's rules allow a rear extension of more than one storey without an application only when it is no deeper than 3 metres and at least 7 metres from the boundary opposite the rear wall, and never on designated land. Most two-storey schemes need householder planning permission.
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. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Horsham like to extend?
Horsham has a mix of Victorian terraces near the centre and larger Edwardian and inter-war houses further out. Clay soils across much of the South East mean deeper foundations near trees, which we plan for at the survey.
How a rear extension in Horsham comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
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 Horsham
Neighbouring places we cover include Broadfield (5.8 miles) and Crawley (7.2 miles).
- Rear extension planning drawings in Broadfield
- Rear extension planning drawings in Crawley
- Rear extension planning drawings in Cranleigh
- Rear extension planning drawings in Horley
- Rear extension planning drawings in Hurstpierpoint
Other work in Horsham:
FAQ
Rear extension planning drawings questions in Horsham
Do I need planning permission for a rear extension in Horsham?
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.
Can you match the brick or stone on my Horsham house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Are the drawings mine?
You can use them to get other quotes, subject to the terms.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
What do rear extension planning drawings cost in Horsham?
As a guide, £1,000–£2,500 including VAT for a single-storey rear extension and £2,000–£3,500 for a two-storey scheme, covering the measured survey, design options and the application. The council fee is extra.
Is the site visit in Horsham free?
Yes. We visit, measure up and talk through the options with no cost and no obligation.