Good insulation means that the outward and inward flow of heat between the interior space and the outside environment runs minimally. Thus, granny flat builders must consider not only the general climate, but also the daily weather patterns in your location.
For all things essential about insulation, here's what you need to know:
Types of Insulation
In any structural type, builders consider how construction materials reduce heat transfer by convection or conduction — or in other words, bulk insulation. While some materials allow pockets of air to circulate from within, others act as effective barriers of heat transfer. Thermally resistant materials include wool, cellulose fibers and polystyrene. But among all of these, polystyrene has become the most popular choice for its affordability and fire-retardant properties.
Reflective insulation, as the name suggests, reduces heat absorption by reflecting radiant heat away from the material. You might best appreciate how this works in places where there is plenty of sunshine. One material that's well known for its reflective properties is the aluminum foil sheet reinforced by a paper of plastic base, otherwise known by builders as reflective foil laminates (RFL).
To maximize the reflective property of RFLs, clean the surface regularly as dust and dirt drastically reduces the sheet's reflective property.
The most energy-efficient materials combine the powers of reflective and bulk insulation. Aluminum foils laminated on batts or blankets made of wool, cotton or even fiberglass make the best shield from harsh weather.
Roof Color and Solar Energy Absorption
External surfaces of walls also significantly affect the amount of radiant heat reflected back from the outside surface. And nothing is as closely associated with solar absorptance as the paint color. Warm and sunny locations call for light colored paints, which absorb solar heat more slowly than dark colored ones.
It may seem counterintuitive, but light colors do not necessary reflect back too much glare that would sometimes be distracting to neighbors. Some paints reflect back majority of the heat but not too much of directly reflected light. Choose only the paints that have these properties to avoid brushing with neighbors over glare issues.
Constructing Your Granny Flat
These are just some of the essentials you need to know about your granny flat insulation. Contact your granny flats builder for more information about the best insulation materials for your flat.