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.
If you have a single-storey extension on your list for a property in Hitchin, we can help from the first measurements to the final clean-up. For a typical home, plan for 10–16 weeks on site, though larger or more complex jobs take longer. We cover postcodes SG6 and nearby Letchworth Garden City, Stevenage and Luton, and every quote we send is fixed for the scope described in it.
- Guide price
- £37,000–£79,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- SG6
- Planning rules
- England
- Local area
- Hertfordshire
- Survey
- Free, with a written quote
What should you budget for a single-storey extension in Hitchin?
Here is how the guide price for a single-storey extension breaks down in Hitchin. 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 Hitchin |
|---|---|---|
| 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 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
What does the job include in Hitchin?
- Groundworks, foundations and below-ground drainage
- Flat or pitched roof, with rooflights or a lantern if specified
- 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
What are homes like around Hitchin?
Hertfordshire is home to the first garden cities, Letchworth and Welwyn Garden City, and the post-war new towns of Stevenage, Hatfield and Hemel Hempstead. Watford and St Albans have Victorian terraces and Georgian streets, interwar semis line the commuter suburbs, and brick-and-flint cottages appear in Chiltern villages to the west.
Generally dry with chalk and clay soils; clay areas can move in long dry spells, and mature trees near houses need considering for foundations.
Knowing the typical building types in Hertfordshire helps, but a survey of your own home in Hitchin is what decides the right approach to a single-storey extension.
Do you need permission in Hitchin?
As Hitchin is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
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.
What happens after you get in touch?
Survey and measure
First, someone visits your home in Hitchin to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Price and scope agreed
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Dates and permissions
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Hitchin property.
Finish and handover
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
Working with SK Home Improvements
Frequently asked questions
How much will a single-storey extension cost in Hitchin?
As a guide, expect to pay £37,000–£79,000 including VAT for a single-storey extension in Hitchin. That range is adjusted for the East of England, which runs about 5% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
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.
What does a typical extension build look like week by week?
A typical single-storey extension follows the same order: clearing the site and digging foundations, building walls up to roof level, then fitting the roof and windows to make it weathertight. Electrics, plumbing, insulation and plastering follow. The last stage is opening into the house, laying the screed and fitting doors and finishes. Building control inspects at key stages, and we book those visits for you.
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a single-storey extension, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
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.
Also covering areas around Hitchin
We survey and quote throughout Hitchin's SG6 postcodes and in surrounding places such as Letchworth Garden City, Stevenage and Luton. The process and pricing approach are identical in each of them.