Retrofitting: A guide for non-residential buildings

Step 10 Get quotes
You can use our to find local installers to undertake the work.
For any major works you should obtain three quotes to ensure that you receive the best deal.
It is important that you have a good understanding of each solution, particularly if it
involves building work. It is easy for important issues to be overlooked. The installer
should have carried out this type of retrofitting work before, and for renewable energy
installations they should have -generation Certification Scheme Accreditation. Any works
undertaken using Green Deal finance should be done by a Green Deal qualified installer.
You should also ensure the installer does not forget about important details such as
minimising air leakages from the building fabric and thermal bridging as these can have a
significant impact on the success of your retrofit (see the boxes below for more
information).
Thermal bridging
Thermal bridges exist where any
material which conducts heat, such as
metal or masonry, links the interior of
the building to the exterior. The
building’s heat is thus lost to the
outside along these thermal bridges.
Thermal bridges tend to exist along
intermediate floors, window and door
lintels (a horizontal piece of wood or
stone above the window or door) and
partition walls. They can often be
identified because they cause surface
condensation, mould growth or
damage to the plaster where they
meet the internal surface. Ensure that
you do not forget to insulate these,
and ensure that your contractor deals
with any thermal bridges they create
through retrofit works, for example by
installing double glazed windows.
Preventing air leakage
In Section 4 you will see how draughtproofing
your building will reduce heat
loss. Draughts can be found anywhere
where the building envelope is
punctured, for example, around door
and window frames and where pipes
and cables enter and leave the
building.
Once you have stopped the draughts in
your building, you want to make sure
that any further retrofit work does not
create more draughts. If you have
double glazing fitted ensure that your
installer takes care to make the
windows airtight. Or if you have a new
boiler fitted, or solar panels fixed to
the roof, ensure that where the pipes/
cables enter the house they are well
sealed.
Step 11 Get planning and/or building control consent
Building Futures Retrofit Module: A guide for non-residential buildings 13