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 Renfrew and the surrounding PA4 postcodes, as well as in Clydebank, Erskine and Paisley. The guide range for this work in Scotland is £33,500–£72,000 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
- £33,500–£72,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- PA4
- Planning rules
- Scotland
- Local area
- Renfrewshire
- Survey
- Free, with a written quote
Single-storey extensions prices in Renfrew
Use the table to gauge the cost of a single-storey extension in Renfrew before we visit. Figures include VAT and are scaled for Scotland, coming out about 4% below the national guide, which gives £33,500–£72,000 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Renfrew |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £21,000–£38,500 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £33,500–£72,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £67,000–£125,000 |
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 do you get?
- 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
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
Building in Renfrew
Paisley has sandstone tenements and terraces from its textile era, Greenock and Port Glasgow have tenements and housing climbing the hills above the Clyde, and Gourock and Kilmacolm have Victorian villas. Post-war estates and newer private housing surround the towns, and roughcast is a common finish.
Inverclyde is one of the wettest parts of lowland Scotland, and homes facing the Firth of Clyde take wind and driving rain.
In Renfrew, as elsewhere in Renfrewshire and Inverclyde, 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 Renfrew
Renfrew is in Scotland, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
In Scotland, Class 1A permitted development covers some single-storey extensions, within limits on depth, height and distance from boundaries, and not in conservation areas or on flats. Anything outside those limits needs planning permission from the council.
A building warrant from the council’s building standards service is usually needed before work starts, and a completion certificate is accepted at the end. There is no Party Wall Act in Scotland; work near a boundary is agreed with neighbours under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
We look at the job
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.
Written quote
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a single-storey extension.
Plan and prepare
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
The work itself
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.
What you can expect from us
Common questions
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.
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 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.
Do you cover Clydebank, Erskine and Paisley?
Yes. As well as Renfrew, we cover Clydebank, Erskine and Paisley and the rest of Renfrewshire and Inverclyde. 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 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 Renfrew
If your address falls within PA4, we cover it. The same goes for neighbouring Clydebank, Erskine and Paisley, which we include alongside Renfrew when arranging surveys and quotes.