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 Newtownards and the surrounding BT23 postcodes, as well as in Bangor, County Down, Castlereagh and Belfast. The guide range for this work in Northern Ireland is £30,000–£64,000 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
- £30,000–£64,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- BT23
- Planning rules
- Northern Ireland
- Local area
- Ards
- Survey
- Free, with a written quote
Single-storey extensions prices in Newtownards
Below is a breakdown of typical costs for a single-storey extension in Newtownards. Because rates in Northern Ireland are about 14% below the national guide, the overall guide comes to £30,000–£64,000, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in Newtownards |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £19,000–£34,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £30,000–£64,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £60,000–£112,000 |
Expect these to shape the final quote:
- 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
Scope of the work
- 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
- Building control inspections and completion certificate
Homes in County Down
County Down takes in suburbs of Belfast, Bangor and Holywood with Victorian and Edwardian villas, and Newry, Downpatrick and Banbridge with older town centres and newer estates. Mourne granite appears in buildings around the mountains, and detached rural homes and bungalows are common across the county, often rendered or pebbledashed.
Coastal areas such as the Ards Peninsula face salt and wind, and the Mournes bring heavier rain and colder conditions.
In Newtownards, as elsewhere in County Down, we take the building's age and construction into account before recommending anything, because both can change what is involved in a single-storey extension.
Permissions for a single-storey extension in Newtownards
Planning law differs across the UK. For a home in Newtownards, it is the Northern Ireland rules below that count, and we check them with the council ahead of any quote.
In Northern Ireland, permitted development allows many single-storey rear extensions, typically up to 3 m deep on attached houses and 4 m on detached houses, within height and garden-coverage limits. Conservation areas, listed buildings and side extensions are more restricted.
Building control approval under the Building Regulations (Northern Ireland) is needed for extensions. Northern Ireland has no Party Wall Act, so boundary work is agreed with neighbours directly.
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?
A visit to your home
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a single-storey extension, and photograph or measure anything the quote needs to reflect.
Quote in writing
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
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
On site to finish
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 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.
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.
How much will a single-storey extension cost in Newtownards?
As a guide, expect to pay £30,000–£64,000 including VAT for a single-storey extension in Newtownards. That range is adjusted for Northern Ireland, which runs about 14% below 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.
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.
How much does a single-storey extension cost?
A typical single-storey rear extension of 15–25m² costs £30,000–£64,000, built to a plastered finish ready for your kitchen and decoration. As a guide, allow roughly £1,600–£2,800 per square metre plus fixed costs for groundworks, steelwork and fees. Smaller extensions cost more per square metre. The kitchen, flooring and large glazed doors are usually the biggest extras. We confirm a fixed price for the agreed specification after the survey.
Near Newtownards
Homes across BT23 in Newtownards are within our coverage, as are those in Bangor, County Down, Castlereagh and Belfast. If you are just outside these areas, ask anyway, because we work right across the UK.

