Converting a Single Integral Garage

This is the cheapest type of garage conversion you can do, and we're going to start with the cheapest possible job you can legally undertake, relevant to this type of garage.

This means we're assuming there's already an internal access door (from the kitchen), the existing floor slab is lower than the house floor, (so you may end up with a step down) and you won't be replacing the existing garage door, simply masking it off.

This will probably give you a windowless room of course.


The basic job

A damp proof membrane, insulation and screed, to create a new floor on top of the existing concrete one.

A vapour barrier, insulation and dry lining to convert the existing exterior brick (side) wall.

A timber, insulated, plasterboarded stud wall, directly behind the up and over door.

A plasterboarded ceiling.

No plastering, just tape and fill the joints between the plasterboard and paint the room, (including the untouched internal house wall).

Fit one radiator, two electrical sockets, one central light and switch, skirting boards, architraving around the door and probably a bit of boxing to hide the gas meter.

That will take two blokes on £150 and £100 per day respectively, 7 days, plus a sparks and a plumber for a day each

Labour £2150.00
Materials £900.00
Building control £350

Basic Job Total £3400.00

The following prices are in addition to this basic job.
Maybe you also have to:

Create a new flush internal door from the house
£550.00

Actually dig out the old floor (because it's too high possibly), and lay a new concrete "base slab" before undertaking the above, "basic job" floor work
£1000.00

Or, if you want to spend a bit more how about.
Putting in a side window
£700.00

Removing the garage door, putting in a new foundation and building a wall and window across the front, to "match" the rest of the house.

This price is minus the amount previously included in the basic job for masking the door. £1300.00

Converting the existing exterior side wall to a cavity wall.

This price includes laying a foundation (which would be done during the floor slab conversion).

We have also deducted from this price, the amount previously included in the basic job for dry lining this wall
£200.00

Plastering all the walls and ceiling
£400.00

Insulating the ceiling
£200.00

Putting in underfloor heating connected to your boiler
£550.00

This price is minus the amount we included in the basic job for fitting a radiator.