A garage conversion turns an integral or attached garage into a warm, habitable room by insulating the floor, walls and ceiling, replacing the garage door with a wall and window, and adding heating, lighting and finishes.
We arrange a garage conversion for homeowners in Grantham and the wider Lincolnshire. The job is planned, priced and managed by us and carried out by tradespeople engaged under our contract, so there is one agreement and one contact. On a typical home the work takes 2–6 weeks on site, and guide pricing in the East Midlands is £11,500–£27,000, VAT included.
- Guide price
- £11,500–£27,000 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- NG31
- Planning rules
- England
- Local area
- Lincolnshire
- Survey
- Free, with a written quote
Garage conversions prices in Grantham
Use the table to gauge the cost of a garage conversion in Grantham before we visit. Figures include VAT and are scaled for the East Midlands, coming out about 4% below the national guide, which gives £11,500–£27,000 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Grantham |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £9,600–£17,500 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £13,500–£24,000 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £21,000–£43,000 |
Expect these to shape the final quote:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Whether a shower room or kitchenette is included
- Heating method and ventilation for the new room
What do you get?
- Foundation checks under the door opening and footings where needed
- Damp-proof membrane, insulated floor and screed or raised timber floor
- Insulated walls and ceiling built to building regulations
- New internal door or opening into the house
- Plastering, skirting and decoration-ready finish
- Building control inspections and completion certificate
What are homes like around Grantham?
Lincoln has limestone buildings on the hill and Victorian brick terraces below, and Stamford is known for its Georgian limestone streets. Red brick and clay pantiles are common across villages, Grimsby and Cleethorpes have Victorian terraces, and the coast from Skegness to Mablethorpe has many bungalows and holiday-era homes.
Lincolnshire is flat and open, with cold easterly winds off the North Sea and flood risk on the coast and in the fens.
So when we survey a Grantham property for a garage conversion, the first step is working out how it was built and what has been changed since.
Permissions for a garage conversion in Grantham
For anyone in Grantham, the relevant framework is England's. The summary below is general, so we always contact the council about your address before putting a price in writing.
In England, converting an attached or integral garage into a room usually needs no planning permission, unless a planning condition on your estate has removed permitted development rights (common on newer houses). Changing the garage door to a wall and window is generally fine.
Building Regulations approval is needed: foundations for the infill wall, a damp-proof course, insulation, ventilation and fire safety.
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?
Free site survey
First, someone visits your home in Grantham 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.
Your fixed price
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.
Getting ready
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.
Build and hand over
Our trades complete a garage conversion while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
What you can expect from us
Frequently asked questions
Which postcodes in Grantham do you cover?
We cover NG31, along with the rest of Lincolnshire. 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.
Will I need building regulations approval?
A garage conversion needs building regulations approval because the space becomes a habitable room. Building control checks that the new wall in the door opening has proper foundations, that the floor has a damp-proof membrane and insulation, and that walls and ceiling meet insulation standards. Ventilation, fire safety and escape routes are also checked. In Scotland a building warrant is normally needed before work starts.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Will the new room be warm enough?
A converted garage can be as warm as any other room in the house, provided the floor, walls and ceiling are insulated to current standards. Garages are usually built with single-skin walls and no insulation, so this work matters. Heating can come from a new radiator on your existing system, underfloor heating or an electric heater, depending on your boiler capacity. We advise on the most suitable option.
Can I keep some storage space?
Many people keep part of the garage for storage by building a dividing wall, leaving a smaller store at the front behind the existing door and converting the area behind into a room or utility. This keeps the look of the house unchanged and gives you somewhere for bikes and tools. The converted part still needs the same insulation, ventilation and fire separation.
Nearby towns
Coverage for Grantham spans NG31. Close by, Newark-on-Trent, Melton Mowbray and Oakham are covered too, and the rest of our UK-wide area follows the same survey-then-quote process from start to finish.

