Garage conversions are becoming increasingly popular with more and more people preferring to change a garage’s purpose from that of storing a car to one of providing another useful living space. Here is an overview of the factors you will need to consider if you’re planning to convert your garage. For an idea of the kind of money you can expect to spend, read How Much Does a Garage Conversion Cost?
What use is a garage conversion?
The most common new use is for a study area whether it be for the business dealings of the parent working from home or the children having a dedicated place to do their homework. Other uses are a playroom, ground floor bedroom, separate dining room (especially if the house has a lounge/dining room) or an annex intended for an elderly relative. Houses with a double garage have the option of retaining one for the use of a car and the other as an extra new room.
The conversion of a garage to any kind of living space is treated as a change of use of part of a building. For most garage conversions all that is necessary is the infilling of the existing garage doorway with a suitably well constructed wall and a window. However any infill of this nature may need to be supported by either foundations or suitable lintels and as such is a structural alteration which requires building regulation approval. An application for approval under the Building Regulations must be made before work starts. The submission of a Building Notice is an appropriate way to achieve this.
When building this new wall, particular care should be taken to ensure that suitable damp proof courses are incorporated to prevent the spread of damp into the existing walls. If the floor does not have a a floor membrane it may be necessary to incorporate one of them to improve the weather resistance of the new room.
Insulation for garage conversions
Insulation is another important consideration so you will need to check your garage to see if it already has cavity walling, if it has then some of the work involved in converting your garage is substantially reduced. If the existing garage has single leaf masonry walls with piers then there will be some additional work to try to improve both the thermal insulation and weather resistance of your new room.It will be necessary to make sure the walls and roof are insulated to industry standards. Windows should achieve a ‘U’ value of 2.0 W/m2/K, Wall insulation value should be equal to 0.35 W/m2/K.
This can be achieved by building new internal block work walls, but these will need support and it cannot be assumed that the existing floor will be adequate to support the extra load. If this is the case it may be necessary to excavate new foundations, or expose the existing ones, to ensure proper support to the block work.
Access to the new room will also need to be considered carefully, preferably off the main hallway, with follow through floor levels, and similar ceiling heights. A window suitable for escape purposes will be required if the new room can only be accessed through another room.
Ventilation for garage conversions
In general garage conversions can be a good idea if the garage is attached to the house if it is detached or some distance away then it is impractical to consider this option for an extra room. Also, you will need to consider the effect of the loss of one car parking space.
Find out about the extra value to your property that a garage conversion can provide here: Garage Conversions – What Value Do They Add?