As we head into summer renovation season, here is a comprehensive set of tips to keep an efficient home, save on utility bills, and increase the aesthetic feel inside and outside.
Don’t create an airtight home without a continuous layer of insulation
If you’re motivated for a high-performing home, you need both airtightness and thermal insulation in sync. Opting for airtightness without insulation will be a terrible disaster and you run the risk of condensation build up. If you focus purely on that gorgeous, continuous insulation layer without an appropriate airtightness layer your home is sure to stay drafty.
Build tight and ventilate right
We all need oxygen to breathe and living in a completely airtight home without the appropriate ventilation is a bad idea. The consensus for an airtight home with under five air changes per hour (ACH) is that it will require a heat recovery ventilation (HRV) system.
A HRV system can be beneficial between 5-10 ACH. A HRV constantly filters air throughout the home, removing pollutants and humidity while transferring heat throughout the home ensuring a comfortable and controlled temperature throughout the home year round.
Ensure your airtight layer is also ‘vapour permeable’
A correctly applied vapour permeable airtightness layer will bullet-proof your home. Your home can have an airtight layer that is also breathable or vapour permeable. This is a key element of any healthy home. An airtight layer needs to enable moisture to travel through it. This will ensure there is no build up of moisture within your home’s wall structure.
There’s a difference between a water control layer (which your airtight layer should be) and a vapour control layer. We don’t want a vapour control layer, we need to ensure vapour is able to travel through your wall system to avoid any problematic condensation build up.
Five per cent of gaps in your home’s insulation can reduce its efficiency by up to 50%. I liken this to jumping in a nice warm bed but your little toes hanging out the end of the duvet. You’ll start to feel cold real quick in that case. Therefore, it’s critically important we get our insulation right. Below are some tips for installing insulation to create energy-efficient homes.
Insulate EVERYWHERE possible
Insulate in everywhere there is a gap between any wall, roof or floor member. Window reveals, plumbing pipes and timber lintels are places that insulation is missed. Ensure that all insulation is a snug fit. Insulation is your home’s blanket, and should be a continuous layer.
Don’t squash or compress your insulation
Common with bulk insulation (opposed to closed cell), which can be easily compressed when pushed into tight spaces. Insulation works by having millions of tiny air pockets within it. Once these pockets are closed the value of the insulation decreases. The more air pockets, the more effective it will be at preventing hot or cold from traveling from outside to inside.
Ensure your insulation is protected from weather
Wet insulation is terrible, not only is it low value insulation, it can cause much worse problems than just a decrease in R-value. If insulation gets wet and stays wet, it can grow mould and be harmful to the occupants of the home. It’s vital to have an appropriate weather-resistant barriers (WRBs) on the exterior of the insulation to prevent any contact with weather.
Ensure your downlights are insulation contact (IC)-rated
The great majority of a home’s heat loss is through the ceiling. Therefore, there’s a preference for less penetrations through a home’s envelope i.e. plasterboard.
As a first preference, we recommend ceiling-mounted lights as the best solution to ensure a continuous layer of ceiling insulation. Although, if downlights are your thing, ensure you select IC-rated downlights which are suitable for close contact with your ceiling insulation.
Avoid thermal bridges
Thermal bridges are a major item to avoid. Most often a steel element (can also be timber) running from the inside of a home to outside, and slicing through that beautiful insulation layer you’ve worked so hard on. With a strong heat and cold conductor like steel, we know what’s going to happen, don’t we?! Just like your little toes hanging out the bed, the thermal bridge is going to pick up on the outside temperature and transfer it inside your home.
This can cause condensation and mould issues. Check your insulation installation thoroughly, because once that plaster goes on your walls, it’s too late to do anything about it.
There’s a saying by Dr Ralf Speth that goes, ‘If you think good design is expensive, you should look at the cost of bad design’. I couldn’t agree with this more. A home MUST be designed with its specific environment in mind. Taking into consideration; nearby buildings and structures, sun and wind direction, gradient of the site, its surrounding area and other factors.
There’s no cookie-cutter approach to achieving the best and most energy-efficient outcomes for individual homes. A principle often used is passive solar design, meaning; a home should use the sun to heat in winter months, yet block the sun out in summer months.
The home’s design should also allow for cross-flow ventilation enabling cooling breezes on a summer’s evening. With the correct passive solar design principles applied this should take a load off mechanical heating and cooling, and save you money and carbon in our atmosphere.