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.
We take on a single-storey extension throughout Hoddesdon and the surrounding EN11 postcodes, as well as in Hertford, Cheshunt and Waltham Abbey. The guide range for this work in the East of England is £37,000–£79,000 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £37,000–£79,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- EN11
- Planning rules
- England
- Local area
- Hertfordshire
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Hoddesdon?
The table below shows guide prices for a single-storey extension in Hoddesdon. They are based on rates in the East of England, which run about 5% above the national guide, giving an overall range of £37,000–£79,000. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Hoddesdon |
|---|---|---|
| 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 |
The main things that change the figure:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
What do you get?
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- 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
- Building control inspections and completion certificate
Homes in Hertfordshire
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.
That variety is why a guide price for a single-storey extension in Hoddesdon is only a starting point; the survey shows what your particular property needs.
Planning and building rules in Hoddesdon
Because Hoddesdon falls under England's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
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
We look at the job
First, someone visits your home in Hoddesdon 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
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Getting ready
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 Hoddesdon property.
Build and hand over
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
Working with SK Home Improvements
Frequently asked questions
Which postcodes in Hoddesdon do you cover?
We cover EN11, along with the rest of Hertfordshire. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
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.
Can you combine a single-storey extension with other work?
Yes. Because we manage several trades under one contract, we can plan a single-storey extension alongside other work on your Hoddesdon home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
How long does a single-storey extension take to build?
A single-storey extension usually takes 10–16 weeks on site, from digging foundations to final plastering. Bad weather, deep foundations or a complex roof can add time. Before work starts, allow several weeks for drawings, structural calculations and building control approval, and longer if planning permission is needed. We give you a stage-by-stage programme with your quote so you know what happens each week.
Also covering areas around Hoddesdon
Live in Hoddesdon? Our coverage takes in the EN11 postcode areas and reaches out to Hertford, Cheshunt and Waltham Abbey, so homes on the outskirts and in the next town along are included.

