Our Guide to insulation
There is no government legislation covering insulation standards for garden offices and other small garden buildings. An inadequately insulated office is not an ‘all-year-round’ building. It will be too cold in winter and too hot in summer.
If offered air-conditioning by an office manufacturer, ask yourself why.
To ensure a steady atmosphere all year round, a wooden building needs to be able to breathe, with air circulating round the structural timbers (the parts of the building that you can’t see). Buildings that don’t breathe retain condensation, need air-conditioning and will eventually rot away; even if they are insulated.
For insulation to work effectively air must be able to circulate around it. Too much insulation crammed into a small space will not be effective. Too little insulation isn’t effective either! Solid plastic and glass fibre insulation materials don’t allow a building to breathe, so must be installed in a garden office building that is ventilated in some a way.
Rockwool is mineral wool insulation that is made using as much recycled material as possible. The Rockwool factory in South Wales heats its own offices using waste heat from the manufacturing process. Rockwool won the Wales Environmental Award in 2002 and continually strives to reduce its energy and water consumption.
2. Thermafleece sheeps wool insulation.
Thermafleece insulation is made from the fleeces of British hill sheep. The manufacturing process uses little energy and the resulting insulation is a natural, low allergy material. We used sheepswool in our own garden office and never regretted it.
Celotex make a large range of solid insulation boards. They make various products for different building situations. Sadly their reputation has been sullied with their involvement in the Grenfell disaster. However, plastic insulations made by a variety of manufacturers are safe for single storey buildings if installed correctly and your building as appropriate fire exits. (In a small, one room building, the main door is usually adequate.)
Insulation is only effective if it is the right insulation to use in a wooden office and is installed according to the manufacturers instructions. If warm moist air comes into contact with a cold surface in a building, condensation occurs and mould starts to grow. This damages paintwork, is unsightly and can cause allergies. If mould grows within the structure of a building the integrity of that building may be affected. The right amount of correctly installed insulation will ensure that this doesn’t happen.
Insulation U Values.
If a garden office is insulated to the level required for a new home you will be certain that it is well insulated and will cost very little to heat. However a lower standard of insulation than this in a very small office will still be effective.
Building Regulations require the following U Values for new houses: –
Roof = 0.20
Floor = 0.22
Walls = 0.30
So it is worth inquiring what the U values of the walls, roof and floor of your new garden office are going to be.