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Q. How much did the home cost to build?
Custom home builders quoted in 2019 the home would cost around $450,000 to build. As this was owner built, it cost considerably less.
Q. How can I estimate how much my house build or renovation will cost?
A great source of information for getting an idea about how much a house build or renovation could cost can be found at: www.archicentreaustralia.com.au/resources/cost-guide.
Q. Are you getting paid to open the home?
No. In short, we (Paul and Jodie) are passionate about energy efficiency and are doing this as a community contribution. Neither of us are getting any payment to open the home.
Many people who have visited the home wonder why we are giving up our weekends to open the home and some people seem to think we could have some ulterior motive.
However, there is no ulterior motive. Paul has taken time away from paid work to build the home and run the tours, while Jodie has taken long service leave from her current job to enable her the time to run tours and provide free advice on weekends and during the week.
Q. Was the build of the home sponsored?
No. Paul paid for the house build himself and took 18 months off work to project manage the build. He did not receive any external funds for this.
The only item that was sponsored was the construction of the studio and green roof, which was sponsored by Ginninderry (this is not included in the build cost noted above). Ginninderry were keen to have a green roof demonstration and if it was not for their direct funding of the studio, it would not have built.
Both government and private entities have been listed for the support they provided to the home, at the bottom of the Demonstration Home webpage. No direct funds were provided, but in-kind contributions or discounts were provided. This included:
- The Federal Government filmed and put together the online videos.
- The ACT Government provided a grant to SEE Change to develop educational materials that supported the demonstration home. These funds paid for the printing of the Buyer’s Guide, the signage around the home and on the trailer, for the construction of the trailer and for the time of the person who presented in the wrapping and sealing videos.
- The companies acknowledged on the website and signage provided a good trade discount rate for products, although as an owner builder trade discounts were received for practically every product. No products were provided for free.
Q. What are the key ways you saved on costs?
Our top 5 ways to save on costs were:
- We used a reverse truss system for the roof over the living area where the ceiling is sloped (see the Section for details). This approach was cheaper than using large beams, lighter for those constructing it and still allows a small person to be able to get into parts of the roof space.
- We have minimal hallway spaces and well-sized rooms. Hallways and rooms that are larger than they need to be, use more materials and are more costly to build. In total this home is 158sqm without the garage and 182sqm including the garage.
- We reduced costs in areas that we could change easily in the future. For example, we installed an Ikea kitchen, robes and bathroom cabinets that we put together ourselves, we chose a simple colour palette of grey and white that allowed us to use cheaper tiles, and we ordered and installed the curtains and curtain tracks ourselves. All of these saved us on purchase and labour costs, and unlike windows or insulation that cannot be easily changed in the future, all of these items are relatively easy to change.
- We project managed and did parts of the build ourselves. By doing this as an Owner builder, project managing the trades and doing aspects ourselves (such as the wall wrap and insulation installation), the home cost significantly less to construct.
Q. How much more did the windows cost compared to standard windows?
The thermally broken aluminum windows cost less than double the cost of un-thermally broken aluminium double-glazed windows.
Costs vary, but project home builders double-glazed window prices may range from $20,000-30,000. The windows in this home cost just over $40,000 (2019 pricing) and included the cost to install the windows.
Q. Who supplied your windows?
We tried to use a local window supplier initially, but could not find a product that had handles and hardware that we liked, and was at the right price point. We therefore looked further afield and found a supplier in Melbourne who uses European hardware made in China, and includes the price of installation as part of the window price. The company we used was Nordic Windows.
Other suppliers that you could consider are:
Q. Did you consider other window types, such as PVC frames?
Yes, we considered PVC window frames as their price is competitive with un-thermally broken aluminum.
We chose not to progress with PVC, as currently there is no way in Australia they can be recycled at end of life or off-cuts recycled during manufacture (this is available at some locations overseas). We also considered timber frames and composite frames (aluminum on the outside and timber on the inside), but full timber frames require a fair amount of maintenance and the composite frames were a similar price to what we got.
As we are monitoring the temperatures in the home and the monitors on the aluminium frame are unexpectedly showing to be a lower temperature than other areas of the room, we think the frames are having an impact on the temperature. If we were to build again, we would therefore consider using a composite frame (aluminum on the outside and timber on the inside).
Q. Does putting triple glazing on a few windows like you did make a difference?
We put triple glazing on a few windows to be able to show people how thick triple glazing units are. Whilst triple glazed windows with a thermally efficient frame would make a difference if installed, and they will make a difference in the room we put it in as this was designed as a ‘cool room’ (to stay cool in summer if the power goes out), it is not efficient to select just a few windows to do this on.
Q. What is the window to floor area ratio?
The floor area of the home including the garage is 182sqm. The area of windows, including window frames, is 45sqm. The window to floor ratio is therefore 25%.
Q. What are the glass thicknesses used in the windows?
The thickness of the glass used in the windows of the home are:
- Windows: 5mm toughened glass, 12mm argon-filled air gap, 5mm toughened glass.
- Sliding doors: 6mm toughened glass, 12mm argon-filled air gap, 6mm toughened glass.
Q. What are the U and SHGC values of the windows?
The U-value of a window measures how well the window and glass conduct heat. It is the inverse of an R-value, which is used in floor, wall and ceiling insulation. This means the lower the U-value, the better the window will be at keeping warmth inside or outside the house. A single glazed window could have a U-value of 6.2, meaning it will conduct 6.2w/m2, whereas a double glazed window can have a U-value of 3.1, meaning it will only conduct 3.1w/m2.
The Solar Heat Gain Coefficient (SHGC) measures how readily heat from direct sunlight flows through a whole window (glass and frame together). SHGC is expressed as a number between 0 and 1, where 1 means 100% of the sunlight flows through the window, 0.5 means 50% of the sunlight flows through the window and 0.43 means 43% of the sunlight flows through the window. The lower a window’s SHGC, the less solar heat it transmits to the house interior.
For more information about U and SHGC values, see the Your Home Glazing webpage.
The U and SHGC values used in the home are:
- Window U-Value: 1.9
- Window SHGC: 0.55
Q. Why did you use ‘Low Iron’ glass?
The glass used throughout the home is ‘low iron’, because it provides a very clear view through the glass with better light transparency. This is a feature used more often in a coastal or bushland surrounding where capturing the views are desirable, rather than in the Canberra suburbs. Low iron glass also blocks UV light, which causes furnishings to fade.
Q. What other factors did you have to consider with your windows?
Other factors we had to consider included:
- Handles – on the outside of the sliding doors we had the option of having opening/closing handles or hand-pulls, and on the outside of the tilt/turn windows that we were considering using as doors, we had the option of having opening/closing handles or nothing.
- Locks – we had the option of no locks and just using the handle in the lock position for the sliding and tilt/turn windows, key lockable from inside and outside, or a turn-switch on the inside and key lock on the outside.
- Flyscreens – we had the option of fixed crim-safe flyscreens that restrict the opening being used as a door and sliding flyscreens on the sliding doors.
Q. Do you have fly screens on your windows and doors?
All openable windows in the home, and the sliding door in the Master Bedroom, are fitted with a crimsafe type metal fly screen.
Fly screens were not included on the large sliding doors in the living area for two reasons. Firstly, these doors are not intended to be used for ventilation purposes. Instead the highlight windows and small window in the kitchen will be used to ventilate this area. Secondly, to maintain aesthetics, it was decided to not to have half the glass covered by a screen.
The screen in the Master Bedroom and in Bedroom 3 were removed over winter, as it was found the screens cut out the solar heat gain in the rooms. They will be refitted before summer.
If building this home again, we would consider reducing the width of the two large sliding doors in the living area, while maintaining the overall amount of glazed area. This would create a smaller opening width that would be easier to open and put a fly screen on, while maintaining the large amount of glazed area to get winter heat gain.
Q. What curtains/blinds did you choose and why?
We were looking for a natural material for our curtains/blinds. We found an option for the curtains (linen and cotton) that were reasonably priced, but not the blinds.
For the curtains, which we installed on the large glazed areas in the bedrooms and media room, we purchased the linen curtains with cotton backing and block-out backing from LinenShed. These curtains are made in Hong Kong and arrived within 1 week of us ordering them. They do charge for the colour sample swatch, so if you are keen to see the different colours the fabrics come in, you can visit us during our tour opening times and have a look at their colour swatch. We ordered the curtain tracks from iseekblinds and installed the ceiling mounted tracks ourselves. They were very easy to install.
For the blinds, which we installed on the smaller glazed areas in the bedrooms, robe and bathrooms, we used honeycomb cellular blinds. These blinds help with energy efficiency and can be fitted into the window frame, which work really well for the tilt-and-turn windows that open inwards. We purchased these from BASC (Blinds, Awnings, Shutters and Curtains) in Canberra who had competitive prices compared to others we got quotes from.
Note: During construction we added extra ceiling battens or timber planks in the ceiling areas where we knew the ceiling mounted curtain tracks were going to be installed. This allowed us very solid fixing through the plasterboard. We would highly recommend this being done at the time of construction. Also, we wanted ‘s-fold’ or ‘wave-fold’ curtains. As the LinenShed curtains come with a standard hook fixing header tape, we sewed the wave-fold header tape (that comes with the curtain tracks) over the top of the LinenShed header tape. It was very easy to do and the finished product looks really good!
Q. Why did you not install pelmets?
We fixed the curtain tracks to the ceiling. When combined with the curtains, there is very little space at the top between the ceiling and curtain. As we also have high-performing windows, we considered the additional benefits that pelmets would give in our situation was not worth the extra effort.
However, in other situations we would consider using pelmets. In an existing home in Lyneham we retrofitted pelmets to the ceiling and combined it with a ceiling mounted curtain track. This gave a very neat finish and improved the comfort and energy performance of the home significantly. We would also consider using a proprietary product like Ezy Pelmet, which gives a very neat finish to the plasterboard, but do come at an additional cost.
Q. What do you suggest to reduce condensation on non-thermally broken aluminium window frames?
Aluminium window frames without a thermal break will conduct the cold from the outside temperature to the inside of the window frame in winter. As the inside temperature will be the opposite of this (warmer inside when it is cold outside), condensation may form on the inside of the window frame. This is particularly noticeable where the window is double glazed, as condensation does not form on the glass but it does form on the aluminium frame.
Ways that condensation could be reduced are with the use of a room dehumidifier, as this will remove excess moisture from the room, or by installing a second frame on the inside of the aluminium frame (see example here).
Q. How do I work out where true north is and how far off true north can my living room windows be?
Most maps are drawn to ‘magnetic’ north, which is what a compass shows. While this is a good indicator for orientating a house, it needs to be adjusted to ‘true’ north to best capture or keep out the sun.
The adjustment figure for true north changes across the country. In Australia’s eastern states, true north can be from 10-14 degrees west of magnetic north (Canberra is around 12 degrees west of magnetic north). In south west of Western Australia it is the opposite and can be 2-4 degrees to the east.
Use a compass or your mobile phone (note mobile phones may not be accurate) to establish magnetic north and then find true north by adding or subtracting the ‘magnetic variation’ for your area using the map in Your Home or www.ga.gov.au/oracle/geomag/agrfform.jsp.
The ideal is to have your living area windows facing within 5 degrees west or 15 degrees east of true north. This will give you total control over your winter and summer sun.
Q. What block or existing home is the best to look out for?
No matter which way your block faces you can still get a good outcome – just as long as you choose a suitable home design. However, choosing a block or existing home with good orientation from the start can make it easier and cheaper.
With blocks getting smaller and the possibility of a two storey house next door, the best orientation is to have your rear boundary facing within 5 degrees west or 15 degrees east of true north. This will give you total control over your winter and summer sun.
Next best is north to the street, but remember, you don’t want your garage taking up over a third of your possible winter sun. In this case, choose a design where you can detach the garage and make a sunny north courtyard between the garage and living area.
If you are looking at buying an existing home and the living areas are not facing north, consider whether the layout of the house or windows could be adjusted to easily allow the living area windows to face north.
While there are options that can go some way to adjust for a poorly orientated block or house, it is always easier to make an informed decision at the start and get your block orientation or existing home as close to perfect as you can.
For a diagram that shows block orientations see page 8 of the Your New Home Buyer’s Guide.
Q. Can I use this design if my block doesn’t face north?
No, if north is to the short side of your block you will need to consider a different design, such as a modified version of the Your Home ‘Acacia’ House Design.
Q. Can I use your floor plan?
Yes, but you will need to ensure it abides with your local Council requirements and it fits on your block with the required setbacks. Some adjustments may be needed. You can download the Demonstration Home Floor Plan and also refer to the Your Home House Designs for different façade and elevation options, or different house designs.
If you happen to be building this in a country other than Australia, you will also need to consider which direction you face the house. Email us if you are not sure.
Q. What is the size of your block, house and living area?
All of these sizes are noted on the detailed floor plan, but in summary the size of the block is 538sqm, the size of the house including the garage is 182sqm, the size of the home not including the garage is 158sqm and the size of the main living area including the kitchen is 60sqm (approx. 9m long x 5m wide + kitchen 5m long x 2.8m wide).
Q. Why did you choose to build a ‘solar passive home’ and not a ‘fully sealed passive house’?
A solar passive home aims to keep a home comfortable and minimise the use of heating and cooling from appliances, by capturing heat from the sun in winter, shading out the sun in summer, using thermal mass internally to moderate temperatures, using windows to capture breezes and ventilate the home, and insulating and sealing the home well to reduce temperature transferring from the outside to the inside.
The benefits of a solar passive home are they reduce energy use, they have limited technology that can break, and they can connect occupants to the external environment – you can read a book or play on your computer while enjoying the sun in the peak of winter, with no heater needed, or get a cool breeze at night flowing over you in the peak of summer!
The downsides of a solar passive home is they do require the occupants to manage the home by opening and closing windows at the appropriate times, and if the sun isn’t shining in winter or temperatures are not getting cool enough outside at night in summer, they will need a bit more heating and cooling from appliances.
A fully sealed passive house (or Passivhaus as it is known in Germany where it began), is a voluntary standard for buildings that is being adopted worldwide. It aims to minimise the amount of heating and cooling that is required from appliances, by being very well insulated and sealed, with low air infiltration and minimal thermal bridging. While they can also incorporate solar passive design, it is not essential. This results in the internal and external environments operating almost completely separately and as the air infiltration rates of a fully sealed passive house are so low, they do require a mechanical air filtration and ventilation system (heat recovery unit) to operate at all times.
The benefits of a fully sealed passive house is they reduce energy use, they are not as reliant on occupants to open and close windows at the appropriate times, they are not as reliant on the sun to keep them warm in winter or the cool night air to keep them cool in summer, the air filtration and ventilation system can improve indoor air quality and they are a comfortable temperature throughout the home.
The downsides of a fully sealed passive house is they do require a mechanical air filtration and ventilation system to run constantly, the air filtration system has filters that need to be changed regularly and some are not recyclable, they do require occupants to understand how they work if they are to operate most effectively and they are more expensive to build.
We built a solar passive home rather than a fully sealed passive house, because we wanted to show how putting a bit of extra time and care into the design and construction of the home, with no major changes to construction practices, can deliver a more comfortable home with reduced energy bills for limited additional construction costs. A fully sealed passive house does require different technology and is more expensive to build.
Q. Is the floor polished concrete?
No, it is burnished concrete.
The difference between a burnished concrete floor and a polished concrete floor, is a burnished floor has the float machine stay a bit longer on the floor when it is first poured. A polished concrete floor has a machine sand the top layers off the floor once it is dry to expose the aggregate and polish the floor. Burnished concrete is less labour intensive as it does not require the separate sanding process, it produces less waste as it does not have layers sanded off and is cheaper than polished concrete.
Q. What concrete floor sealant did you use and what are your tips for applying the sealant?
We used a clear ‘Livos‘ linus and kunos natural linseed oil sealant on the concrete floors.
We applied the primer and sealant as per the Livos Info Sheet, but the key tips we have when applying the floor sealant by hand in addition to this Info Sheet are:
- Use a cotton cloth to apply both the primer and sealant coats.
- We tried a few different application methods, including a paint brush and a roller, but found using a cotton cloth was the best way to apply the primer, sealant and sealant top coats.
- Apply the primer and sealant coats in circular motions and wipe off any excess.
- We found putting the primer and sealant on a small section at a time that your arm can reach over, working that area in circular motions and then wiping off the excess, seemed to work the best for us.
- Ignore any patchiness.
- One mistake we made was in one room, when after having the primer coat dry we thought it looked a bit patchy, we gave the floor a second coat of the primer. This then couldn’t dry and we had to use steel wool to get it off. So don’t worry if the first primer coat looks ordinary – the top coats of the sealant even it out and cover any variations.
Q. Did you insulate the concrete slab?
No, we did not insulate the concrete slab.
The concrete slab we used is a typical waffle pod slab construction, which in summary has the ground levelled (we had it dug in on the far corner and built up on the street corner) and then large polystyrene waffle pods are laid out, steelwork is installed and the areas between and along the edges of each waffle pod (known as ribs and edge beams), along with the slab on top of the waffle pods, are concreted. Sometimes people consider the waffle pods as a form of insulation, however they are not designed as a coherent form of under-slab insulation and are primarily designed to reduce the amount of concrete needed, and to simplify the floor construction process.
The reasons we did not insulate the concrete slab, is because:
- It adds extra complexity to the build. In many cases edge insulation is damaged by trades that come after, so it has to be replaced and may not perform as intended.
- It may provide a path for termites to travel, particularly if gardens or mulch are located around the perimeter. This home does not use chemical termite barriers, so exposing the outside of the slab allows easy inspection for termites.
- We considered the amount of extra costs to properly insulate the slab could be better spent on other energy efficiency elements in the home.
Q. What types of insulation did you use?
The breathable wall wrap and tape to seal the home that was used was ‘CSR Bradford’ breathable Enviroseal RW wall wrap and ‘CSR Bradford’ Enviroseal HighTack Proctor Tape.
The wall insulation used was ‘CSR Bradford’ Gold Hi-Performance R2.5 batts. This uses glasswool, which is molten glass made from around 80% recycled glass.
The ceiling insulation used was ‘CSR Bradford’ Gold R4.1 batts above the plasterboard ceiling and ‘CSR Bradford’ Anticon R1.3 blanket under the metal roof.
Q. Why did you insulate some internal walls?
The reason insulation was added between bathrooms and living rooms, between bedrooms and living rooms and between bedrooms, was to reduce unwanted noise transfer between these differing spaces.
We used ‘Bradford Insulation Soundscreen R2.0’ batts and they have worked really well. Overall the house is very quiet.
Q. Why was soundproof plasterboard not used, particularly in the large open living space?
Acoustic insulation batts were used instead of soundproof plasterboard, because it could be easily installed by the Owner and was much cheaper than soundproof plasterboard.
While the acoustic batts do not provide 100% deadening of noise between all of the rooms, overall the Owner has been very happy with their performance. Even the large open living space, with lots of hard surfaces, does not echo.
Q. What termite protection did you use?
We used a perforated stainless steel mesh around all plumbing and electrical pipes that penetrated the concrete slab and we have made sure we can do a visual inspection around the full external perimeter of the slab. We did not use any chemical termite protection treatments.
Q. What is the cost of the Weathertex cladding and how does it compare with other cladding types?
The Weathertex panels used in this home were: WeatherGroove 1200mm Smooth, Selflok Ecogroove 300 Smooth and WeatherGroove 150mm Natural. Each panel type are a different cost.
As an example of costs and comparisons with other cladding products, the Weathertex WeatherGroove cladding like that used on the outside walls of the green roof studio, comes in panels 2440 x 1196 x 9.5mm (2.9sqm) and is $199.00 from Bunnings. You then need to add the costs of accessories, like cavity battens, cavity closers and metal corner finishing strips. A similar commonly used James Hardie fibre cement product called HardieGroove Lining, comes in panels 2700 x 1200 x 7.5mm (3.2sqm) and is $154.00 from Bunnings. While the cost of bricks for 2.9sqm could cost anywhere between $51.07-$437.74 depending on the choice of brick, plus the labour and mortar costs.
Weathertex was used as it is Australian made of 97% hardwood timber and 3% natural wax for water repellence. It also has the benefits of being easy to cut, as it is a timber product, and it does not produce unhealthy bi-products when it is cut, like cement fibre products do.
GRASS DRIVEWAY AND GREEN ROOF
Q. Will cars wear out areas in the grass driveway?
It is too early to tell, but we expect there may be some wear on the grass from cars using the driveway. If it becomes too dramatic, we will fill the wear areas with bark chip, stone or something similar. The grid underneath provides stability, drainage and flexibility for whatever is laid on top.
Q. How much did the plastic grid used under the grass driveway cost?
The plastic grid used under the grass driveway called ‘Geohex’, costs $15 per grid panel or $30 per square metre (there are two grid panels per square metre), GST inclusive. The grids can be purchased in pallets that are 85 square metres per pallet.
If you are in the Canberra Region they can be purchased from the Wholesale Sleeper Company in Queanbeyan.
Q. How much did the green roof studio cost?
The main cost for the green roof studio was in the waterproofing, which cost $5,000.
The rest of the construction for the studio was standard, but with some additional timber structure in the roof and wall frames to support the added weight of the roof. Plywood was also used on the wall lining in the studio, which adds extra rigidity to the structure.
Details for how the green roof was constructed is outlined in the demonstration videos.
APPLIANCES AND RENEWABLES
Q. What type of heat pump hot water system did you use and why?
We chose a Stiebel Eltron 222H, which has 220 litres of hot water capacity and an extra 90 litre boost capacity (310 capacity total). Stiebel Eltron also have a 302 litre option (302H), but we chose the 222H because it has a better coefficient of performance (COP)* – 3.94 compared to 3.58.
* A COP of 3.94 means for every 1 unit of energy used to power the system, the system will produce 3.94 units of energy to heat the water. The higher the COP, the more efficient the system is.
While the Stiebel Eltron 302H seems good value for money (it’s only $100 extra), we considered 220 (310) litres was a sufficient amount of hot water for a small household and having a more efficient system was more important. Also, if more hot water is needed the battery and solar panels can be used to heat it.
Sanden and Reclaim are also well-regarded brands. Unlike the Stiebel Eltron that has the compressor on the tank, the Sanden and Reclaim system has the compressor separate to the tank, which may be more flexible to locate in some situations. The Sanden and Reclaim system also have the ability for the system to be put on a timer and only come on when the sun is shining. This is particularly useful if using the hot water system to act like a battery and store the energy produced from the solar panels.
We chose the Stiebel Eltron because it was cheaper and as we have a battery, we did not need to choose a system with the timer ability.
Q. What type of heating and cooling system have you used and why?
We chose a Daikin multi-head reverse cycle air conditioner, as it much more efficient than a fully ducted system. It has one outside compressor unit that can run multiple heads – we can have up to 5 inside units – and each inside unit can be set at their own temperature. Daikin also has a good reputation, this unit is the quietest compressor on the market that we could find, it is energy efficient and it has R32 Refrigerant, which enables increased energy efficiency and a significant reduction in ‘Global Warming Potential Factor’.
Our system has model numbers: outside unit 5MXM100RVMA; media room inside unit CTXM25RVMA (2.5kW); and living room inside unit CTXM71RVMA (7.1kW).
The Energy Efficiency Ratio (EER) and coefficient of performance (COP)* for this unit if there are 5 inside units, is 3.91 for cooling and 4.72 for heating.
* An EER for cooling operation and COP for heating operation indicate how efficiently the unit uses energy. A higher EER and COP mean greater energy efficiency. For example, a COP of 4.72 means for every 1 unit of energy used to power the system, the system will produce 4.72 units of energy to heat the home.
Placement of the outside compressor unit on small blocks needs to be carefully considered, as they could impact yours or neighbours bedrooms. Note: The Daikin unit we chose is one of the quieter options available to help overcome this issue.
Q. How does the Daikin multi-head system compare to other systems in price?
The Daikin multi-head system consisting of one outside unit and 2 inside units cost us $5,366 supplied and installed. If an additional 3 indoor units were added for the bedrooms, it would likely cost $1,155 + installation. This would total $6,521 + installation for 3 extra indoor units.
When compared to other options, the Daikin multi-head system is very competitive in price and as they have only one outside unit, it is very good on space saving:
- Two separate split systems of a similar size would cost around $3,400 + installation costs and if another 3 of these systems were added for the bedrooms, it would cost an extra $3,195 + installation. This would total $6,600 + installation for all 5 units.
- A 10kw Daikin reverse cycle ducted system that covers 3 bedrooms + 1 lounge/living + kitchen would cost $12,350 supplied and installed.
Q. Is there a way to estimate the size of an air-conditioning system needed for a room?
Yes there is. This Choice article covers the key considerations for sizing air conditioners and gives a rough estimate of the size based on room sizes. However, the final sizing of your air conditioner should be decided based on a combination of your research and discussions with your air conditioner supplier and installer.
Q. What type of solar system do you have and why did you choose it?
We have 6.6kW of solar panels from ‘Mondiaux Solar’ located on the 6.3° south facing roof. The almost flat south facing panels lose around 5% efficiency, so the savings we made in not propping up the panels on frames was spent on the extra 1.6kW in panels to compensate for the losses. The panel orientation may also allow extra earnings in late summer afternoons once time-of-day metering is introduced. This will be monitored and reported on after the first full summer period.
We chose to go with Mondiaux Solar as their prices were most competitive at the time, they offered a good quality product and they provided a very professional site inspection and quote process.
Q. What type of battery do you have and why did you choose that one?
We have two SolaX 5.8kWh Triple Power solar lithium batteries. This gives us a total of 11.6kWh of battery storage.
We chose these batteries because some appealing subsidies were being offered for a mini-grid trial in Ginninderry and this was the battery being offered by our solar provider ‘Mondiaux Solar’. If we were not part of this trial and if we had to pay full price for the batteries, we wouldn’t have installed them and waited for prices of batteries to come down.
Q. Who were the suppliers of the different products you used?
The list of products used on this home, and the suppliers of these products, can be found at the bottom of the Demonstration Home webpage.
Q. Who supplied your light fittings?
Most of the lights, including the pendant lights, were from Beacon Lighting.
The spotlights in the kitchen, study and outside the master bedroom, and the light in the garage, were from Project Lighting.
Q. What are your suggestions for improving existing homes?
We have developed this ‘Tips for Improving an Existing Home’ (pdf). Our key suggestions are to:
- Seal gaps around doors and windows using rolls of seals that can be purchased from hardware stores.
- Seal gaps around door and window architraves, skirtings and cornices with a sealant like ‘Fuller Ultra Clear’ (it is water-based, and it goes on white and dries clear).
- Install pelmets and heavy curtains.
- Consider where insulation can be installed and/or topped up.
- Consider retrofitting double glazed windows with good performing window frames.
- Look at the following websites: My Efficient Electric Home; Green It Yourself; Example case study – COOEE Architecture.
It is worth noting that once the home is well sealed, consideration may need to be given to removing moisture from inside the home, particularly if you have a gas cooker or heater. As the existing wall wrap is unlikely to be breathable, a build-up of moisture could result in mould issues. Something like a dehumidifier could be considered to remove excess moisture.
Q. How many frogs are there in the home?
That is for us to know and for children visiting the home to find and count!
Q. Are you going to seal under and around the cavity sliding doors?
At this stage no, as we do not think the losses in heating or cooling will be too great.
We placed the cavity sliding doors in the main living areas to enable us to zone and separate these spaces from the adjacent room, which will reduce the amount of heating or cooling needed to keep the rooms comfortable. The doors do a relatively good job of separating these spaces, however they do have some gaps around them, particularly along the bottom of the doors.
During construction we could have taken extra steps to put seals on the bottom of the doors, noting after the doors are in place they are not easy to remove or fit seals to, but we chose not to add seals as this would have added extra time and costs with somewhat limited returns. As the spaces on the other sides of the doors are well sealed and insulated, and the heating/cooling unit is efficient and primarily running off renewable energy generated on site, the extra time and costs associated with fitting custom seals was not considered necessary.
Q. What temperature monitors have you used and where can people purchase them from?
The temperature monitors are ‘Wirelesstag’. They provide data about the temperature, humidity and when the window or door is opened or closed. You can set how often you want them to measure (we have ours set for 15 minutes) and the data can be displayed on their website and a mobile phone app in real time and in graphs over time. You do need to have the internet connected for these to work.
These monitors can be purchased in Australia (https://wirelesstag.com.au) or directly from the USA (https://wirelesstag.net/ and https://store.wirelesstag.net/en-au/collections/all)
Ours were purchased from the USA because they were significantly cheaper (AUD$71 for the manager, AUD$35 for the sensor from the USA versus $236 for the manager and $129 for the tags from the Australian store). When these tags were originally purchased a discount was offered if the tags were bought as a bundle of 5. As the tags were bought from the USA, a power adaptor had to be purchased separately and you cannot return it locally if you have issues – you have to ship it back to the USA.
A locally purchased power supply would be something like the following: https://www.officeworks.com.au/shop/officeworks/p/comsol-male-type-a-usb-2-0-to-male-mini-usb-cable-2m-cou2amb02; https://www.officeworks.com.au/shop/officeworks/p/comsol-single-port-usb-wall-charger-1a-black-cowcs10blk.
Q. Is this home being used to promote Commonsense Sustainability Solutions?
No, this home is not being used to promote the private company ‘Commonsense Sustainability Solutions’, which Paul is the Director of.
However, the company’s website is being used to promote the house, as it is a website we have access to, and in some cases companies and organisations feel more comfortable dealing with an entity, not an individual person.
As you will see on the Commonsense Sustainability Solutions website, there is no mention of services that could be offered for a fee, as this is not being used as a business promotion opportunity.
Currently Paul is not working and is offering free advice to anyone who visits the home. This includes giving up time each weekend to show people through the home, opening the home during the week for groups that are interested in seeing it and meeting people for separate design advice sessions at no cost outside of the times when the home is open. Paul is not getting, or seeking, any payment for this advice or for his time doing this.
Paul also intends to travel next year after the house openings are complete, so he has no intention of getting future business as he will not be around.
Q. Are you actually living in the home, as it doesn’t look like it?
We have been living in the home full time since July 2022.
We have minimised the items we keep in the home and tidy the home each morning that a group comes through, so that people can feel comfortable looking around the home and opening cupboards. By doing this we hope they do not feel like they are imposing on our personal space.
We also want to present this house like the other display homes and inspire people, so we have minimised what we have around the home and we pack things away before the house is opened. So it may look like we are not living in the home, but we are.