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 live in Yarm and are weighing up a single-storey extension, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across TS15 and TS16, and a typical project of this kind in Yorkshire and the Humber lands somewhere in the £33,000–£70,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £33,000–£70,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- TS15 and TS16
- Planning rules
- England
- Local area
- Stockton-on-Tees
- Survey
- Free, with a written quote
What should you budget for a single-storey extension in Yarm?
What will a single-storey extension cost in Yarm? Our guide range is £33,000–£70,000 including VAT. That figure is adjusted for Yorkshire and the Humber, about 6% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Yarm |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,500–£37,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,000–£70,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £66,000–£122,000 |
Your price depends mostly on:
- 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
- Finishes, kitchen, flooring and heating specification
Scope of the work
- 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
- Electrics and plumbing by qualified trades, with certificates
- Windows and external doors, including bifolds if chosen
- Building control inspections and completion certificate
Local housing and a single-storey extension
York has medieval timber-framed, Georgian and Victorian buildings, Harrogate has stone Victorian villas and terraces, and the Dales and Moors are built of limestone and sandstone, often under stone-slate or pantile roofs. Teesside towns within the county, such as Middlesbrough and Redcar, have Victorian red-brick terraces and post-war estates.
High ground in the Dales and Moors sees snow, frost and strong winds, while the coast faces cold North Sea weather.
Whatever era your Yarm home dates from, we plan a single-storey extension around how it is actually built rather than a one-size-fits-all specification.
Permissions for a single-storey extension in Yarm
Each UK nation sets its own consent rules, and Yarm 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.
How does the job run?
We look at the job
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a single-storey extension so the price reflects your home.
Price and scope agreed
After the survey we send a quote for a single-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
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 Yarm property.
Build and hand over
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
How we work
Questions about a single-storey extension in Yarm
Do you cover Thornaby-on-Tees, Stockton-on-Tees and Billingham?
Yes. As well as Yarm, we cover Thornaby-on-Tees, Stockton-on-Tees and Billingham and the rest of North Yorkshire. 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 the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
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.
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.
Can we stay at home during the build?
Most people stay at home while we build a single-storey extension, because the new structure goes up outside before we break through. The disruptive part is usually the last few weeks, when we open into the house and fit the kitchen. We put up dust screens, keep a safe route through the house and agree a temporary kitchen setup if needed. Water and power are only off for short, planned periods.
Near Yarm
Addresses in TS15 and TS16 are all covered for Yarm, along with Thornaby-on-Tees, Stockton-on-Tees and Billingham close by. Give us your postcode when you get in touch and we will confirm the details.

