Bedroom extensions in Hitchin: design, approvals and build
If you live in Hitchin and want more space without moving, a bedroom extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in HitchinFrom £27,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsSG4, SG5
Is a bedroom extension right for your house?
- Growing families
- Multi-generational households
- Homeowners who want an en-suite master bedroom
New bedrooms on an upper floor need an escape window or a protected route to the outside under the building regulations. We design the window sizes and stair route to meet that from the outset.
How much does a bedroom extension cost in Hitchin?
Labour and material costs vary across the UK, so for Hitchin we use our East of England factor (×1.06). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Hitchin: £1,700 to £3,390 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £27,500 – £34,000 | £27,500 – £36,000 | £30,500 – £41,000 |
| Bedroom and en-suite 18 m² | £30,500 – £37,500 | £36,000 – £47,000 | £45,500 – £61,500 |
| Two rooms 30 m² | £50,500 – £62,500 | £60,000 – £78,000 | £76,000 – £102,000 |
Try the guide-price tool to see a range for your own size and finish.
Working in Hitchin
We cover Hitchin and the postcode districts SG4, SG5. Neighbouring towns we cover include Letchworth Garden City (3 miles), Stevenage (5 miles), Harpenden (10 miles), Welwyn Garden City (11 miles).
Luton, in Bedfordshire, is roughly 7 miles from Hitchin and also on our list. The East of England mixes market-town terraces, inter-war semis and modern estates. Clay soils are common in parts of the region, which can affect foundation design.
Will the council need to approve it?
In England a two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
From first visit to completion
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Hitchin home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Work is carried out to the agreed programme, inspected by building control and signed off at the end.
Questions people ask about bedroom extensions
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Hitchin, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How long does a bedroom extension take to build in Hitchin?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Do I need building regulations approval in Hitchin?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does an en-suite need a window?
No, but it needs mechanical extraction that meets the building regulations. We design the duct route at the drawing stage.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
Book a free site visit in Hitchin
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.