Blackburn, Lancashire
Rear extension planning drawings in Blackburn
Thinking about a rear extension in Blackburn? Measured survey, design options, planning drawings and the application, handled for you. Our team handles the drawings, the planning route and the build, and your contract is with one company throughout.
We cover Blackburn (BB1, BB2 and BB3) as part of our Lancashire work. For Blackburn 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 Blackburn?
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 Blackburn?
Planning for a rear extension in Blackburn follows the English householder rules.
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. 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 Blackburn like to extend?
Stone and brick terraces are common around Blackburn. Where houses back onto a ginnel or alley, deliveries can come in from the rear, which makes the build tidier.
How a rear extension in Blackburn 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.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Rear extension planning drawings near Blackburn
Neighbouring places we cover include Darwen (3.7 miles) and Great Harwood (3.9 miles).
- Rear extension planning drawings in Darwen
- Rear extension planning drawings in Great Harwood
- Rear extension planning drawings in Accrington
- Rear extension planning drawings in Haslingden
- Rear extension planning drawings in Padiham
Other work in Blackburn:
FAQ
Rear extension planning drawings questions in Blackburn
Do you handle building control in Blackburn?
Yes. We apply to the council or a registered building control approver and hand over the completion certificate.
Can you match the brick or stone on my Blackburn house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Do I need an architect?
You need accurate drawings by someone who knows householder planning; we provide them.
What do rear extension planning drawings cost in Blackburn?
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.
How long does a rear extension take to build in Blackburn?
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 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.