7 MAIN FACTORS THAT CAN INFLUENCE COSTS

1 SIZE/ECONOMIES OF SCALE

Generally speaking, the smaller the garage the lower the cost per m2 – less materials, labour and so on, subject to the intended purpose, which we’ll consider below. However, economies of scale can be achieved with converting larger double garages, so while the overall cost may be higher, a reduction can be achieved in the cost per m2, giving better value for money. Remember also that garages don’t need to be converted in their entirety. If you want to maintain a storage element, you can partition off a section and convert the remainder. Storage space in a home is invaluable so if you can retain what you need and still add a room, you can minimise your costs and achieve two usable spaces.

2 LOCATION

If you happen to live in or around London, your location can impact labour costs by around 25%.

3 CONDITION OF THE EXISTING GARAGE

If your existing garage is in a poor state of repair, then you will incur additional costs to remedy any issues with the structure. If the works required are extensive then you should get accurate costings from an experienced quantity surveyor, as in this scenario it may be just as cost effective and less hassle to replace it with a new extension.

4 EXTENT OF WORK REQUIRED

An integrated garage will generally always be cheaper than any other type to convert, as it is already connected to the home, whereas an attached garage will require the connection to be made. Each project will have its own design variations and even an integrated garage with an existing access may need to be converted with a much larger opening if you’re planning to expand an adjacent room. Creating a wide opening in a load-bearing wall will be more expensive than simply adding a door.

5 FUNCTION OF THE NEW ROOM

If the purpose of your conversion is additional space for something simple like an office, bedroom or additional living room, then the average costs will include what you’ll need in terms of the basic requirements of lighting, electric points and heating. However, if you’re seeking to add a utility or bathroom, the cost will go up. You’ll need to take account of the water supply, plumbing and drainage requirements, not to mention the cost of appliances and bathroom suites.

6 DESIGN AND QUALITY

Your choice of specification and finish can add thousands to the budget. Flooring choices can range from £25/m2 to over £100/m2. There is a huge cost difference between opting for standard UPVC patio doors and the latest ultra-thin aluminium bifold doors. Opting for high-end appliances can add around £2,000 to a small utility room, and that’s before you even start to consider the vast range of cost options for kitchens and bathrooms.

7 ANCILLARY STORAGE NEEDS

If your garage previously housed things like your gardening tools, bikes and so on, then you’ll need to factor in the cost of a secure shed to store those items, if you don’t already have one.