Insulation
Insulation to the external walls and ceiling comes as part of the standard inclusions package in most new homes. However, upgrading from the standard, and installing insulation in more areas is definitely worth considering, because insulation often has more benefits than just controlling your new home’s temperature.
Insulation is graded using R-values. R-values indicate thermal resistance, or how well the product reduces heat flow. Insulations R-values start at 1.0 or 1.5, and can extend right up to 7.0. It might seem natural to go with the highest possible values in both your walls and ceilings, but its important to remember that insulation will also stop heat leaving your home, and stop it entering your home in winter. As such, the Australian Government’s Your Home Technical Manual recommends that homes in a temperate, humid climate like Sydney use roof and ceiling insulation with R-values between 1.5 and 3.0, and wall insulation of around 1.5.
The most common insulation used in new homes is batts. These batts are usually made of fibreglass, although they can also be made of polyester and wool. Manufacturers claim that this form of insulation can help keep a new home up to seven degrees cooler in the hot months. There are also special forms of insulation available that cut down on noise, as well as heat transfer. These are similar to fibreglass batts, except they’re made of rockwool, a type of melted volcanic rock. Rockwool batts are often installed between rooms, in the internal walls of a home, to cut down on noise infesting more rooms than it has to.
If you’re building in a bush fire prone area, development controls will probably insist that you add sarking. Fire retardant sarking is a material layer installed under the roof tiles or sheeting to prevent burning embers entering through a home’s roof. However, sarking is also a form of insulation, and can very effectively reflect the heat that beats down on your roof during the long summer days
Active Cooling
So you’ve passively designed until you can passively design no more, and now its time to take action, and turn something on.
Remember, there are two costs to consider with every active cooling option- the initial cost of installing the system, plus the continued cost of running the system. Sometimes, the best value is a trade off between these two elements.
