Hatfield house extensions
More space without moving: we plan and build extensions across Hatfield, with one team for the drawings, the council and the build.
- Postcode districtsAL7, AL8, AL9, AL10
- Price regionEast of England (×1.06)
- Planning rulesEngland
- Site visitFree, no obligation
Planning and building control in Hatfield
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).
What extensions cost in Hatfield
We publish guide prices so you can budget before anyone visits. For Hatfield they are adjusted by ×1.06, the factor we use across East of England.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Extensions over a garage | 12 m² | £26,500 – £34,500 |
| Side return extensions | 11 m² | £27,500 – £35,000 |
| Single-storey rear extensions | 20 m² | £43,000 – £55,500 |
| Conservatory replacement extensions | 14 m² | £31,500 – £41,000 |
| Wraparound extensions | 25 m² | £60,500 – £77,000 |
| Double-storey extensions | 32 m² | £61,000 – £80,000 |
| Orangery extensions | 16 m² | £47,000 – £59,500 |
Where we work near Hatfield
Across AL7, AL8, AL9, AL10, we can visit, measure and advise. We also work in nearby Welwyn Garden City (3 miles), St Albans (5 miles), Potters Bar (5 miles), Hertford (7 miles), Harpenden (7 miles). For homes towards Greater London, Barnet is around 8 miles away.
What works best for Hatfield houses?
Across the East of England many houses sit on generous plots, and single-storey and wraparound extensions are a natural fit.
Depending on the plot, single-storey rear extensions and wraparound extensions are often the strongest options, with double-storey extensions worth considering where there is room.
All extension types we build in Hatfield
- Extensions over a garage · from £25,000
- Flat roof extensions · from £22,000
- Orangery extensions · from £31,500
- Single-storey rear extensions · from £22,000
- Annexe extensions · from £58,000
- Home office extensions · from £16,500
- Kitchen extensions · from £28,500
- Side extensions · from £23,000
- Bedroom extensions · from £27,500
- Porch extensions · from £4,200
- Planning permission for extensions · from £350
- Utility and boot room extensions · from £14,500
- Double-storey extensions · from £40,000
- Glass box extensions · from £31,500
- Conservatory replacement extensions · from £21,000
- Extension plans and drawings · from £1,250
- Wraparound extensions · from £38,000
- Building regulations for extensions · from £950
- Side return extensions · from £19,000
- Timber frame extensions · from £22,000
- Pitched roof extensions · from £23,500
- Bungalow extensions · from £27,500
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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 Hatfield
How much does an extension cost in Hatfield?
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.
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.
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.
Do I need planning permission for an extension in Hatfield?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Book a free site visit in Hatfield
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.