House extensions in Hertford
Every type of house extension in Hertford, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsSG13, SG14
- Price regionEast of England (×1.06)
- Planning rulesEngland
- Site visitFree, no obligation
What extensions cost in Hertford
Prices on this page use our East of England factor of ×1.06, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Wraparound extensions | 25 m² | £60,500 – £77,000 |
| Extensions over a garage | 12 m² | £26,500 – £34,500 |
| Single-storey rear extensions | 20 m² | £43,000 – £55,500 |
| Kitchen extensions | 20 m² | £44,500 – £56,500 |
| Conservatory replacement extensions | 14 m² | £31,500 – £41,000 |
Do extensions in Hertford need planning permission?
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 works best for Hertford 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, bungalow extensions and double-storey extensions are often the strongest options, with wraparound extensions worth considering where there is room.
Covering Hertford and nearby
Postcode districts we cover around Hertford include SG13, SG14. We also work in nearby Hoddesdon (4 miles), Welwyn Garden City (6 miles), Hatfield (7 miles), Cheshunt (7 miles), Potters Bar (8 miles). Just over the Essex border, Waltham Abbey is about 8 miles away.
Choose an extension type
- Home office extensions · from £16,500
- Kitchen extensions · from £28,500
- Wraparound extensions · from £38,000
- Conservatory replacement extensions · from £21,000
- Timber frame extensions · from £22,000
- Flat roof extensions · from £22,000
- Double-storey extensions · from £40,000
- Planning permission for extensions · from £350
- Side extensions · from £23,000
- Building regulations for extensions · from £950
- Porch extensions · from £4,200
- Bedroom extensions · from £27,500
- Glass box extensions · from £31,500
- Side return extensions · from £19,000
- Extension plans and drawings · from £1,250
- Extensions over a garage · from £25,000
- Annexe extensions · from £58,000
- Utility and boot room extensions · from £14,500
- Pitched roof extensions · from £23,500
- Bungalow extensions · from £27,500
- Orangery extensions · from £31,500
- Single-storey rear extensions · from £22,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
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 Hertford
How much does an extension cost in Hertford?
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 Hertford, 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 Hertford?
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.
Do you cover all of Hertford?
Yes, including the surrounding parts of Hertfordshire. Site visits are free and there is no obligation.
Book a free site visit in Hertford
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.