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 offer a single-storey extension across County Durham, and Stockton-on-Tees is one of the places we cover, along with nearby Billingham, Thornaby-on-Tees and Middlesbrough. Before anything is agreed we visit, check the existing structure and talk through your options. You then receive a written quote setting out the full scope; for most homes in the North East it sits within £31,500–£68,000 including VAT.
- Guide price
- £31,500–£68,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- TS17, TS18, TS19 and TS20
- Planning rules
- England
- Local area
- County Durham
- Survey
- Free, with a written quote
How much does a single-storey extension cost in Stockton-on-Tees?
The table below shows guide prices for a single-storey extension in Stockton-on-Tees. They are based on rates in the North East, which run about 10% below the national guide, giving an overall range of £31,500–£68,000. All figures include VAT and are firmed up after a free site survey.
| Type of job | What it usually involves | Guide in Stockton-on-Tees |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £20,000–£36,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £31,500–£68,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £63,000–£117,000 |
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
What’s included?
- 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
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
What are homes like around Stockton-on-Tees?
Colliery villages across County Durham are lined with brick and stone terraces, many built for mining families. Durham City has Georgian and Victorian streets, Darlington has Victorian terraces and villas, and Peterlee and Newton Aycliffe were planned as post-war new towns. Dales farmhouses in Weardale and Teesdale are stone, often under stone or slate roofs.
Colliery terraces commonly suit loft rooms, rear extensions and window replacement, and many need repointing. New-town homes often benefit from rendering or cladding upgrades and roofline renewal, while stone farmhouses may need lime work.
For a single-storey extension in Stockton-on-Tees, this means checking things like wall construction, roof structure and existing services before we put a figure on paper.
Permissions for a single-storey extension in Stockton-on-Tees
Which rules apply depends on where you live. For Stockton-on-Tees, the answer is England, and the points below reflect that; we verify them with the council before quoting.
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
A visit to your home
A free survey comes first. It gives us what we need to price a single-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Getting ready
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
The work itself
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
How we work
Frequently asked questions
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.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Do you cover Billingham, Thornaby-on-Tees and Middlesbrough?
Yes. As well as Stockton-on-Tees, we cover Billingham, Thornaby-on-Tees and Middlesbrough and the rest of County Durham. 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.
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.
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.
Near Stockton-on-Tees
We welcome enquiries from all TS17, TS18, TS19 and TS20 postcodes in Stockton-on-Tees, plus Billingham, Thornaby-on-Tees and Middlesbrough. Each one gets the same survey at no charge and a written price fixed for the work described.