Major Projects Should You Convert Your Garage?

Date Published:

19/09/2009

What’s involved with the building work?

Foundations

Expect part of the garage floor to be excavated to allow for new foundations to support a new wall replacing the garage door. Nigel Lewis has a neat solution. ‘A simple trick to avoid large volumes of excavation, muck away and concrete foundations is to provide lintels set just below ground level which can bear on sound masonry or existing foundations each end.’

Floor

The old garage floor is likely to be lower than the floor in the house due to fire regulations, and this will have to be raised. ‘The floor will need to be protected from rising damp, insulated to a certain degree and raised to bring it level with the house. While building regulations do not require the floor levels to be the same it is usually considered good practice to make the conversion feel more like part of the home,’ advises Nigel Lewis.

Walls

Unless you are lucky enough to have a fully integral garage, large areas of the external walls will usually be made of a single course of bricks and won’t meet building regulations regarding moisture and insulation. The insulation and weatherproofing of the outside walls can be achieved in a number of ways, but Nigel has a good solution. ‘The method I prefer is to create an independent stud wall built off a damp course on a couple of courses of bricks set 75mm clear of the original wall. This stud wall can easily accommodate services and insulation prior to plasterboarding.’

Windows

New windows won’t usually need planning permission, though under the latest regulations, they will need to be energy efficient and double glazed. Match them to the existing house for a sympathetic conversion. If the new room is termed by building control as being an inner room, meaning that you have to travel through another room rather than into a hallway to escape, then the window will need to be suitable as a means of escape.

Insulation & Ventilation

The new structure will need to meet building regulations in terms of insulation of the walls, floor and roof, and background ventilation is needed via airbricks or trickle vents.

Heating

The choice of space heating depends on the existing heating system in the house and the depth of the new floor construction. If the new floor will be at least 150mm thick, an underfloor heating system as an extension of the existing central heating can be considered. If the floor construction is less than this, consider electric underfloor heating, or simply add radiators to the existing system (ensuring first with your heating engineer that your boiler can cope with an extra radiator).