Garage Conversion Building Regulations UK - What are the main requirements for
All garage conversions are usually considered to be a material alteration which requires
a certain level of minimum standards to be met for the change of use into a habitable room. This is controlled and
monitored by the Building Regulations which is usually by the Local Council. However, unbeknown to most homeowners,
you are able to submit your scheme for Building Regulations approval to a Private Building Inspector not attached
to the local Council. These are known as Approved Inspectors.
Most independent House extension building designers or architects still use the Local Councils Building
Inspector for their Building Regulations submission for garage conversions whilst many garage conversion
specialists contractors offer a design and build service tend to use a Private Building Inspector or have set up a
partnering agreement with their favoured Local Authority simply for a consistency of approach when determining
Under the Building Regulations garage conversions (or any other change of use for that matter) carry a degree of
flexibility of what is actually required for compliance. The thermal improvement and upgrading of the existing
garage structure is the main one.
Sometimes thermally improving the existing garage floor can be very costly or impractical is there is not a
decent enough difference in floor levels for the new insulation and floor covering for example. So, rather than
breaking up the existing garage floor which is very costly, there is a way of the Building Regulations accepting a
lower thermal standard if it can be proven that the payback period for the proper works required is greater than 15
This is simply a basic mathematical exercise but requires some knowledge of ‘U’ values and energy costs. Some
awkward Building Inspectors require this to be completed by a SAP Assessor that uses a government approved piece of
software but this can be expensive and outside the control of your garage conversion designer or agent.
The other parts of compliance under Building Regulations applicable to garage conversions are the usual heating,
structural elements of the adaptations or new build works, lighting, electrics, drainage and waste provision if a
new WC, utility, kitchen or washing facilities are proposed.
The risks and trip wires most homeowners face is to underestimate the importance of Building Regulations
Compliance for a garage conversion. Many DIY’ers and budget constrained home owners often see any home conversion
works as a simplistic practical task devoid of any design requirements or third party approval process.
This is a big mistake and is perhaps the one major reason why most house purchases fall through at the last
minute - failure to provide the necessary consents and council approvals so why take the risk? Always use an
experienced house extension designer or architect to prepare plans and specifications not only for your builders
use but to obtain the required Building Regulation Consents.
In most Cases specific formal Planning Approval is not required but there are instances when
it is, so be warned, - check with the Planning Department as well. This planning or permitted development issue
relating to garage conversions is a separate topic in its own right which is covered elsewhere.