A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
In Norfolk, we price a single-storey extension against our guide for the East of England, £37,000–£79,000 including VAT, then adjust it once we have surveyed your home. We work across Norwich, Great Yarmouth, King's Lynn and Thetford and the rest of the county or region. Planning and building control requirements follow the rules for England, and we look into your property's position before a written quote is sent.
- Guide price
- £37,000–£79,000 inc VAT
- Time on site
- 10–16 weeks on site
- Planning rules
- England
- Price level
- About 5% above the national guide
- Towns listed
- 6
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Norfolk?
Here is how the guide price for a single-storey extension breaks down in Norfolk. We start from national figures and adjust for the East of England, which comes out about 5% above the national guide. The resulting range, VAT included, is £37,000–£79,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Norfolk |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £23,000–£42,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £37,000–£79,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £74,000–£136,000 |
Your price depends mostly on:
- Floor area, shape and number of corners
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What do you get?
- Groundworks, foundations and below-ground drainage
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Housing across Norfolk
Flint is everywhere in Norfolk, often combined with brick quoins and red or black-glazed pantile roofs. Norwich has Victorian terraces and interwar suburbs around its medieval centre, Norfolk reed thatch survives across the county, carrstone is used in the west, and coastal towns such as Great Yarmouth and Cromer have Victorian terraces and newer bungalows.
Flint walls often need lime repointing and careful repairs, and pantile roofs need matching tiles. Norwich terraces suit loft conversions and rear extensions, while coastal bungalows commonly take loft rooms, porches and new windows.
Norfolk is dry but exposed, with strong easterly winds, an eroding coast in places and low-lying land around the Broads.
Planning and building rules in Norfolk
Each UK nation sets its own consent rules, and Norfolk is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
Survey and measure
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a single-storey extension.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Dates and permissions
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
On site to finish
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
How we work
Frequently asked questions
How long will a single-storey extension take?
On a typical home, allow 10–16 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Do you cover Norwich, Great Yarmouth and King's Lynn?
Yes. As well as Norfolk, we cover Norwich, Great Yarmouth and King's Lynn and the rest of Norfolk. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
Do I need planning permission for a single-storey extension?
Whether you need planning permission depends on the extension's size and height, how close it is to boundaries, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many rear extensions up to 3m deep on a semi or terrace, or 4m on a detached house, can be built under permitted development. We check the rules that apply to your home before quoting.
What is the Party Wall Act and does it apply to me?
The Party Wall etc. Act 1996 applies in England and Wales only. In England and Wales, it requires you to give notice to neighbours before certain work on or near a shared wall, such as digging foundations within 3m of their building and deeper than its footings. Neighbours can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act, though general rights still apply. We identify whether notices are needed during the survey.
Towns in Norfolk
These are the towns in Norfolk where you can book a free survey for a single-storey extension. Each has its own page with guide prices and coverage details.