Extending your home in Hitchin
Planning an extension in Hitchin? Compare extension types, see guide prices adjusted for Hitchin and book a free site visit.
- Postcode districtsSG4, SG5
- Price regionEast of England (×1.06)
- Planning rulesEngland
- Site visitFree, no obligation
Planning rules in Hitchin
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
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).
Which extension suits a Hitchin home?
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Start by comparing wraparound extensions, double-storey extensions and bungalow extensions: between them they cover most of the layouts we see requested for houses like these.
Covering Hitchin and nearby
Across SG4, SG5, we can visit, measure and advise. The same team covers Letchworth Garden City (3 miles), Stevenage (5 miles), Harpenden (10 miles), Welwyn Garden City (11 miles), Hatfield (13 miles), all within easy reach. For homes towards Bedfordshire, Luton is around 7 miles away.
What extensions cost in Hitchin
Every figure below is a guide for Hitchin, adjusted for East of England build costs (×1.06) and including VAT. Design and council fees are shown separately on each page.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Extensions over a garage | 12 m² | £26,500 – £34,500 |
| Single-storey rear extensions | 20 m² | £43,000 – £55,500 |
| Side return extensions | 11 m² | £27,500 – £35,000 |
| Orangery extensions | 16 m² | £47,000 – £59,500 |
| Conservatory replacement extensions | 14 m² | £31,500 – £41,000 |
| Double-storey extensions | 32 m² | £61,000 – £80,000 |
| Kitchen extensions | 20 m² | £44,500 – £56,500 |
Extension types and starting prices
- Orangery extensions · from £31,500
- Utility and boot room extensions · from £14,500
- Timber frame extensions · from £22,000
- Side extensions · from £23,000
- Pitched roof extensions · from £23,500
- Side return extensions · from £19,000
- Building regulations for extensions · from £950
- Flat roof extensions · from £22,000
- Glass box extensions · from £31,500
- Conservatory replacement extensions · from £21,000
- Planning permission for extensions · from £350
- Annexe extensions · from £58,000
- Wraparound extensions · from £38,000
- Extension plans and drawings · from £1,250
- Extensions over a garage · from £25,000
- Double-storey extensions · from £40,000
- Porch extensions · from £4,200
- Kitchen extensions · from £28,500
- Single-storey rear extensions · from £22,000
- Home office extensions · from £16,500
- Bungalow extensions · from £27,500
- Bedroom extensions · from £27,500
Free site visit
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
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 about extensions in Hitchin
How much does an extension cost in Hitchin?
Using our East of England factor (×1.06), a standard-spec single-storey extension of 20 m² is a guide £43,000 to £55,500 including VAT, and a 32 m² two-storey extension £61,000 to £80,000. Your written price follows the survey.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Hitchin, and the guide-price tool gives a range for your own size and finish in about a minute.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does an extension take in Hitchin?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
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.