Knotty Ash, Merseyside
Rear extension planning drawings in Knotty Ash
Measured survey, design options, planning drawings and the application, handled for you. If you live in Knotty Ash and want to know what a rear extension would cost and whether it needs planning, start with the online guide price or a free site visit.
Knotty Ash is covered from our Merseyside round, including L13, L14 and L16. Planning applications in Knotty Ash go to the local planning authority covering Knotty Ash, and we check its local design guidance for rear extensions before drawing.
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 Knotty Ash?
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 Knotty Ash?
The planning route for a rear extension in Knotty Ash is set by England's householder rules and your council.
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 Knotty Ash like to extend?
Stone and brick terraces are common around Knotty Ash. 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 Knotty Ash comes together
Survey visit
We visit free of charge, measure up, check access, drainage and neighbours' extensions, and note what you want the room to do.
Design and guide price
Two or three layout options with a guide price for each, so you choose the design knowing what it costs.
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 Knotty Ash
Close by, we work in Old Swan, about 0.5 miles away, and West Derby, about 1.3 miles away.
- Rear extension planning drawings in Old Swan
- Rear extension planning drawings in West Derby
- Rear extension planning drawings in Childwall
- Rear extension planning drawings in Wavertree
- Rear extension planning drawings in Norris Green
Other work in Knotty Ash:
FAQ
Rear extension planning drawings questions in Knotty Ash
Can you match the brick or stone on my Knotty Ash house?
We source the closest match and show you samples before ordering; reclaimed materials are often the best match on older houses.
Who will build my extension?
Vetted building teams working under contract to us. Your contract is with S&K Property Investments and Improvement Ltd for the design and the build.
Can planning conditions affect the build?
Yes, for example matching materials or obscure glazing. We plan for them.
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
How long does a rear extension take to build in Knotty Ash?
Most single-storey rear extensions take 10 to 16 weeks on site and two-storey extensions 16 to 26 weeks, after design and approvals.
What do rear extension planning drawings cost in Knotty Ash?
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.