Green Moves Australia - 1 to 7 Stars

About the House

A Bayside Melbourne home was looking for major renovations and were keen to find a way to measure the impact of the changes we were looking to incorporate. A before and after measure is what was needed. At the time of planning the renovation works, we were lucky to be included in one of the initial Victorian Governments Residential Efficiency Scorecard trials so we obtained a Scorecard rating before the renovations. The baseline Scorecard rating came in at just 1 Star, which is very inefficient and indicates that the home would be costly to run. We also used local Melbourne business Efficiency Matrix to conduct a blower door test to measure the ‘leakiness’ of the house which significantly effects the cost to run and comfort levels. The blower door test revealed an Air Change per Hour (ACH) rate of 20.20 ACH which is three times the average amount of 5.0 ACH. All that leakage equated to a hole in the home of about 1000mm x 500mm, or a window of that size being open in the house all the time. That’s a lot of discomfort and energy wasted. Our baseline measures were a 1 Star Scorecard Rating, 20.2 ACH air leakage and a 36-kWh day energy use average. The house was a tired 2 storey 4 bedroom home with an in-ground saltwater pool, built in the 1980s in East Brighton. Many of the original features were in the home when purchased, including the original kitchen, bathrooms and external deck which had rotted through in parts. The home had many major appliances that were past their ‘best before’ dates (inc gas ducted heating, electric and gas storage hot water, ovens), inefficient halogen downlights and lots of drafts. All that points to high energy bills and an uncomfortable and drafty home. The energy use was 36kWh per day on average, which is more than double the Melbourne average, and it was quite drafty in the winter months. However, the home did have ‘very good bones’ with excellent north-facing living space overlooking a pool, good sized rooms and a huge opportunity to provide a beautiful comfortable home that cost very little to run.

Planning and Redesign

This was the time we got to practice what we preach. The goal was to modernise the home while maximising energy efficiency potential. We spent time investigating the opportunities the renovation presented and engaged local residents and architects (Sue Coles from Baenziger Coles) to assist with some innovative ideas in terms of improving the layout. Through removing some walls, repositioning some windows and modifying the internal layout we were able to maximise the northern light and passive heat into the home and open up the kitchen and family living space. We now had an updated, more practical and open plan layout for the main living areas that facilitated better use of space and the ability to close areas off as and when needed through hidden ceiling to floor sliding doors. Although the internal conditioned floor space was actually reduced by 7m2 (through the removal of very leaky ‘conservatory’ type areas) the area looks and feels modern, spacious and has more natural light.

The Building Works

Getting the layout/design right was important as 80% of the energy efficiency of a home can come back to design. But other items such as insulation, glazing and draft proofing also need to be done well. We hired local builders Jeremy and Sue Gates from Gaia Constructions to work with and were very happy with the result. Apart from the structural changes required to update the internal layout (including removing two structural walls), we replaced all single glazed windows and doors with double glazed thermally improved frames. Internal lighting was upgraded to IC4 rated LED downlights and drivers (so they can be insulated over). Exhaust fans were upgraded to self-closing types to reduce heat loss in winter and draft sealing was done. External walls were insulated to R2 level as most were open for other reasons, so we took the opportunity to really improve the building shell. Ceiling insulation was upgraded to R5 (after all trades were finished), and roof vents with temperature sensors were installed to help vent hot air in summer. The gas ducted heating was replaced with a highly efficient condensing boiler and hydronic panel system. A new efficient reverse cycle system was installed in the family room area for those ‘in between' times. Existing reverse cycle units in bedrooms were serviced and retained. Ceiling fans have been installed in all bedrooms and the main family room and have proven a good investment. The hot water system was upgraded to a 6-star instant gas unit. The home was completely re-painted with low VOC paints, some of the cabinetry was recycled into the study area saving money and waste of some good quality cabinetry. The flooring was replaced with hard-wearing low VOC floating boards and carpet with underlay from recycled materials. A newly redesigned kitchen from Made in Italy kitchens was installed providing low VOC and carbon neutral cabinetry. Highly efficient Miele and Siemens appliances were installed with water efficient tapware. An innovative new front door creates a stunning statement piece and was designed by our own Danielle King. It was made to facilitate good natural ventilation whilst maintaining the efficiency and security of the property. The door, insulated steel with double glazed operable panels, offers security while allowing cooling breezes from the south to enter the home when open.

Outside and the Pool

The external rotted rear deck was removed and replaced with sustainably sourced wood, increased area and 4,000L of rainwater tanks (servicing toilet and herb garden irrigation) was installed under the deck. An adjustable louvre Vergola roof was installed to allow light and shelter as needed throughout the year to the outdoor patio and kitchen areas. Adjustable shading in the form of an automated blind was installed on the large north-facing sliding door to the pool area. The pool needed to be resurfaced so it was tiled to provide longevity. The filtration system was upgraded to Ozone which uses significantly fewer chemicals and only needs to run for half the time of other filtration units. The water is also low chemical (greywater safe) so water from backwashing can go onto the garden. The pool is not heated and has a cover which is used regularly.

Energy and Monitoring

Finally, a 3.15kW battery ready solar PV system has also been installed with monitoring. Other energy monitoring includes circuit monitoring of heating/cooling, lighting, kitchen and pool equipment through the Clipsal Wiser Link system.