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Garage Conversions

Due to the size of modern cars, garages in the UK are rarely used as a place to park a car and instead, they end up being used for storage.

Converting a garage into a usable room, such as a bedroom, studio or just an additional room is a great way to make better use of the space and add value to your house. The cost of converting a garage to a bedroom or similar is generally 70% cheaper than adding a similar size extension as the structural shell is already in place.

Garage Conversions and things to consider

There are a few things to consider before undertaking a garage conversion project of your own. We've broken them down on this page to help you gain a better understanding on the process and the various options available along the way.

Planning permission for a garage conversion usually isn't required, but a Building Control application will be required in either form of technical drawings or more straightforward schemes, the building notice route may be sufficient, by informing the local authority of your intent to start work 48 hours prior to commencing on site. A Building Control package is a set of technical drawings and construction details that are submitted to your local council for approval to ensure it will be built correctly, using the correct building standards. The package needs to show that the proposed garage conversion will be built correctly, and safely and that it will meet (or exceed) the national minimum requirements.

Floor slab

An existing concrete floor might well be strong enough to cope with general domestic use, however, the garage floor will most likely not be level. As a result, it may need to be leveled with a self-leveling liquid screed. It may also be damp-proofed with a suitable membrane (lapping into the walls’ DPC) and insulated with rigid insulation to achieve adequate thermal performance within your garage conversion.

garage floor conversion

Garage Door Removal 

The most common option with a garage conversion is to replace the garage door with a conventional brick wall to match the rest of the property. This could be a masonry infill fully toothed and bonded into the existing brickwork, or a timber partition wall to allow for cement board cladding and thicker insulation. 

The design stage assessment of your garage conversion should identify whether the foundations need upgrading to take the new loads. Planning allowing - you could introduce more daylight into the space by adding a window or a glazed access door.  This may also help reduce the loads imposed on the foundations.


garage door conversion

Wall Insulation

Some garages are built to the same standard as the main house (with cavity wall insulation) so the walls may not need upgrading. It is however more likely that your attached or detached garage is single-skin construction. This must be insulated internally to meet standards. This is usually achieved by erecting stud walling using timbers deep enough to accept sufficient rigid insulation, normally 90mm plus an air gap. This also provides a hidden route for additional electric outlets or things like central heating pipes within your new garage conversion.

Another option with your garage conversion could be to retain part of the space (and even the door), to create a smaller storage area or if your garage is large enough - you could even retain space for a single car. If you go down the part conversion route, we’d need to erect a fully-insulated, internal dividing wall that is designed to provide 30-minute fire protection. This can be done by erecting a fully insulated timber stud wall that's boarded on both sides with a fire-rated pink plasterboard.


garage wall insulation

Roof insulation

The simplest way to insulate a pitched garage roof during a conversion is at loft/ceiling level. With a pitched covering, 270mm of mineral wool should be sufficient – 100mm between the joists, and the rest on top.  A flat roofed garage conversion will need to be fitted with rigid insulation between and under the ceiling joists, with a ventilation gap above to prevent condensation.

If the floor-to-ceiling height is tight a slim multifoil system can be used as a space-saving alternative.

garage conversion roof insulation

Windows & Doors

Always install a door or window to your garage conversion that matches the existing ones found throughout the house. FENSA specify will need to hit the required whole-unit U-values (1.6 W/m2K for windows; 1.8 for doors).

Match your security expectations, provide adequate ventilation and suit the style of your home. Casements, sashes, and door sets can be incorporated into additional exterior walls by knocking through a suitable hole in the wall, facing brickwork, and adding lintels as required. 

For larger spans enabling a more open-plan feel, a reinforcing steel beam may be needed in your garage conversion. This kind of work may require calculations from a structural engineer.


garage conversion tunbridge wells

Heating & Electrics

LED downlights are a good choice for ceiling illumination in most garage conversions. They can be easily integrated into the new ceiling structure. Adding additional sockets within the garage can also easily be done so it's worth thinking about what you plan on doing in your garage conversion when finished to ensure adequate plugs are accounted for.

Heating-wise, plumbing in a suitably-sized radiator will be the most cost-effective solution for the majority of garage conversions. Ventilation is another key issue. Openable windows, fitted with trickle vents, will be sufficient in most cases – but if you’re incorporating a bathroom or kitchen, you’ll need a powerful enough extractor fan to manage moisture build-up in your newly converted space.

garage conversion lighting

Interior & Finishing 

Once the initial work is complete we'll finish off your garage conversion by plaster-boarding all internal walls, allowing for a two-coat multi-finish plaster. Once dry all walls will be mist-coated white and finished in a paint RAL colour of your choice.

Finally skirting board and architraves will be installed (generally to match existing throughout the house) and the newly converted space will be finished with wood flooring or carpet.

All that's left then is for you to move into your newly converted garage and use the space to its full potential.

garage conversion tunbridge wells

Book an appointment

Reach out to discuss your new garage conversion project today and a member of the team will get back to you to run through the next steps.