In the Metricon process, selections were carried out after signing of the preliminary contract. Selections were broken down into 5 separate appointments including HVAC, Electrical, Tiling, Cabinets and Studio M. Here we discuss
HVAC
Heating, Ventilation and Cooling, also known as HVAC, is key to maintaining comfort in your home. We had grand plans of creating an eco-friendly house utilising passive and low energy heating and cooling technologies. Unfortunately, Australia is a little behind in this area as our typical climate range does not see the extremes of Europe or North America. As a result, high efficiency cooling and heating is typically sourced at a premium.
To maintain comfort within our home, in addition to the standard roof and wall insulation, we added insulation to our subfloor and all internal walls. We also added a ducted reverse cycle air conditioning with smart control and insulated ducting (15.5 kW Cooling / 18 kW Heating). Its smart controller allow for individual temperature control within each room. Our solar panels would offset the usage of the air conditioner unit during the day. We also added an electric roof ventilation to minimise heat in the roof cavity. Another feature to reduce heat loss were the “draftstoppers” installed on ventilation fans.
There were some other features that we would have liked to have considered but were out of our price range. These include:
- Underfloor hydronic heating
- Ground source heat pump
- High COF heat pump water heater
- Highly insulated wall materials
- Fresh Air heat exchanger
It should be noted that other practical measures for maximising performance of HVAC system include careful selection of window coverings. For example, pelmets and “heat blocking” materials, as well as draft protectors on external doors and garage doors. Even opening and closing windows and window coverings at the right time of day/night for passive heating or cooling can help.
Insulation was standard in the roof and external walls. Because the construction was brick veneer, additional insulation was installed in the internal walls and in the subfloor between the floors. We neglected to add reflective foil insulation directly under the Colorbond metal roof panels. This would have helped reflect heat and reduce roof cavity temperatures.
Another feature that we neglected to incorporate due to costs was double glazing of all windows and doors. This feature effectively adds insulation to the windows which are known to readily transfer heat. In hindsight we would have liked to have installed double glazing to provide further passive insulation and sarking under our colourbond roofing.
Electrical
We took a lot of time to plan our electrical layout and components. The first component was laying out lights. Before the meeting we opted for downlights and attempted to layout what we thought were a reasonable number of lights through the house plans. This wasn’t our area of expertise, and we were actually told to reduce the number of lights in some of our larger living areas.
The next part involved us walking through our design in our heads to determine where we would like the switches in relation to how we would move throughout the house. In some cases, 2- or 3-way switches were incorporated to allow flexibility of turning on/off hall or stair lights from either end. This is a pretty typical function, but if you have multiple hallways or passageways, it may pay to split lighting for utility.
The next part we looked at was powerpoints. How many times have you been somewhere and there just isn’t a powerpoint in the right spot? Often this requires a non-ideal workaround, like having to run an extension cord around the back of the room or under a rug!
We opted for the approach of having more rather than less powerpoints. We tried to think of appliance locations, lamps, places to charge phones and plug in vacuum cleaners. Looking round the house now, I can say that I think we got it pretty close to right. We also opted to install powerpoints at height for wall hung TV’s, as well as installing conduit for any cables. We added ethernet data cabling to the office, and living areas to reduce strain on the WIFI network.
Other items we opted for included ceiling fans, as on most days we are comfortable with a bit of air movement rather than AC. We also installed a gas cooktop. However, to add future flexibility, we ensured that we installed a dedicated circuit to allow for electric induction cooktop if we ever decided to change. Other future proofing included addition of several junction boxes to the external to allow for outdoor wiring or appliances. We also added a doorbell and appropriate wiring.
Some things we didn’t get right though. I would have liked to have installed ethernet cables to the security camera locations for POE cameras. Additionally, I wish that we had added a three-phase connection to allow for running of heavy-duty electrical goods. Another nice to have would have been to run conduit underground for routing external wiring for things like outdoor lighting, electric gates etc.