UPDATED: A Nationwide House Energy Rating Scheme (NatHERS) rating of 8.7 for a Queensland home is always worthy of investigation in The Fifth Estate’s books. But we were interested to discover that there was nothing particularly radical or expensive about this Brisbane home designed by dion seminara architecture, and that the high thermal performance rating came down to “really good design”.

Many people wanting to build their dream home think energy efficiency and sustainability come at a major price premium thanks to costly add-ons.

But a home in the Brisbane suburb of Sherwood designed by Dion Seminara and his team was completed on a tight budget for a retiree client.

It is well insulated, has double-glazed windows and a special colour coating on the roof that reflects heat, as well as 62 solar panels on a roof pitched to maximise power generation (the client is a solar enthusiast). But Seminara told The Fifth Estate all of these features were manageable under the tight budget.

The secret to achieving the high thermal rating without breaking the bank was simply “really good design” by the architects, but it helped to engage a high-quality energy rating assessor, SUHO, which is based in Adelaide.

The consultancy recommended a few “minor tweaks”, such has the positioning of the insulation, which helped push the rating up still higher.

“An 8.7 NatHERS rating is blitzing it.”

He said the home might have even achieved a few extra decimal points with a different slab but that was too expensive.

“You have to weigh up the costs and decide if it’s worth it.”

The high thermal performance rating for the home which, compared to a typical 6-star rated home, uses about 80 per cent less energy to cool or heat, came down to basic energy-conscious design around orientation, layout, cross-flow ventilation and shading. In Brisbane’s hot, humid climate this included big overhanging eaves and some external screening on certain windows on the east to try and block the sun.

The home is also laid out to get the “maximum benefit for the majority of the major rooms of the home,” with the garage on the back of the property in the worst corner.

Seminara, who takes a holistic approach to sustainable design, also says it’s important to consider the social sustainability of a home. He works hard to put the entertaining and living areas in the best spots in all his projects.

The client is a big user of airconditioning, but as a retiree, will be able to take full advantage of the extensive solar array as they will use most of their energy during the day.

Seminara expects very low power bills for the client, who was interested in a sustainable home for a number of reasons, including a financing agreement that offered a discount if certain sustainability measures were met.

The flat site was selected by the client to get the most out of the solar panels, with no vegetation from neighbouring properties shading the site. However, the architects have encouraged the client to plant vegetation to help shade the house.

Note: An earlier version of this article implied that the high peformance design was attributed to the energy consultant, rather than the architects.

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  1. This is a great result. Well done. Just a few things to note:
    8.7 star (20Mj/sqm/a) is 54% saving on 6 star (43mj/sqm/a) not 80% as stated. It is important to consider the overall performance of the homes energy. The article correctly identified that this star rating measures only heating and cooling. All plug loads,hot water, pool pumps are not included in the star calculation. The 62 solar panels(probably about 19kW array) should produce about 70kWh a day, a serious generation well done. This will blitz the heating cooling loads. Although use is not linear throughout the year if it were then the AC/heating would consume about 2.3kWh/day. Lots of solar spare. So the challenge now is to use that energy through the day by changing habits. For instance one change would be AC use. During those hot steamy Brisbane summer days leave the AC running on economy when you are not home. The solar is covering it. Then there is no spike of power when you come home to a hot house and try and drop the temp as quickly as possible.
    The reason we have personal trainers in gyms is to show us how to use the equipment properly. We need to do the same with our smart homes. Understand how you get the best out of it. COMFORT is what we are looking for 365. This is a great start at 8.7 stars and well done to all concerned but make sure you include all of the operational and maintenance around the technology and enjoy your great Sherwood home. Congratulations

  2. To get the best outcomes you need a bespoke design which does lose the commercial efficiency of project building. Each aspect NWSE presents a different challenge as does lot size and topography.

  3. I’d love to see a picture of the roof & roof shape & design in relation to the orientation of the solar panels.
    In a typical passive solar home with skillion roof – the panels would face to the south.
    Our renos will have the skillion tilt down at the north side- to optimise the PV production with about another 10 kW, so we can provide all the energy our EV will need as well as out home
    This facebook group would really like to see stories like this: https://www.facebook.com/groups/996387660405677/

  4. Hi Poppy. I hope this message finds you well.

    Your article got me thinking about how my house would rate. I live in a Queenslander built ca 1930. We export way more solar energy than we use, we have solar hot water, are off the grid with gas (use swap n go bottles) and have rainwater tanks that we use for the garden and toilet/laundry.

    Consequently we receive an electricity credit each quarter and have very low gas and water bills.

    Just thought it was worth mentioning as it’s a DIY ‘retrofit’ solution as opposed to a professionally designed solution that many readers would think is out of their budget.

    (I also realise this may well be an article applauding the great work delivered by one of your conrtibutors).

    Cheers, Brendan.