Building designer Elizabeth Wheeler of Future Focus Buildings and home energy assessor Tamar Boyd, owner of Blue Lotus Energy Rating, have taken out both the national and Victorian awards for the True Zero Carbon Challenge 2022 by Design Matters National.
The award conducted by Design Matters National, Australia’s peak industry body for building designers and home energy assessors, recognises design and energy assessment work for a house that produces more power than it uses over a year, and is net zero in embodied carbon.
Dubbed Omnia House (from the Latin meaning prepared in all things or ready for anything), Wheeler considered energy efficiency at the start of the process, a departure from the more common add-on or afterthought approach of the industry.
One of this year’s judges Jeremy Spencer, director, builder and energy assessor at Positive Footprints, announced the winners on Friday 11 November in the carbon neutral Rainforest Room at Melbourne Zoo.
Notably, all the winners, selected in a blind assessment process by the judging panel, were women.
The house design is for a floor size of 165 square metres, with a 8.3 NatHERS stars rating in a north-facing orientation, and a minimum of 7.3 stars in any other orientation in Victoria. With a 13.7 kilowatt solar system, if built to plan using the specifications provided, it would be carbon positive by 2050.
Omnia House is designed to achieve Australian Livable Housing Guidelines Platinum levels for the bedroom, bathroom, and circulation spaces, and Gold for other parts.
“I didn’t want something that required bells and whistles, I wanted something any builder can build,” designer Elizabeth Wheeler tells The Fifth Estate.
“The house showcases good passive solar design and strategic material choices.
“We wanted to design something that performed well thermally, that was small, and had considered environmental specifications.”
Design Matters National chief executive Peta Anderson says the project is a “real stand-out, sustainable, and ready to build. Omnia House makes a strong sustainable statement and is an exceptional conceptual design.”
The cost of construction is estimated to be $707,617 including the photovoltaic system and elements such as permeable paving, internal and external blinds, and landscaping.
Without these extras, the price drops to $600,000.
Anderson notes the the judging panel comprising Jeremy Spencer from Positive Footprints, Luke Middleton from EME Design, Caroline Noller from The Footprint Company and Richard Stokes from Arup, all commended the landscaping design.
“Omnia House’s edible garden with raised wicking beds and dwarf fruit forest provided organic produce, and the front lockable bike port encouraged healthy transport habits,” Anderson says.
The winners:
State commendations:
- Swift Parrot House by James Goodlet and Daniel Prochazka
- The Smarter Sustainable Home by Griff Morris and Debbie Bute
Student award:
- Bare House by Alicia Ferrer and Tristan Stanley-Cary
State winners:
- Omnia House by Elizabeth Wheeler and Tamar Boyd (VIC)
- Secret Garden Home by Suho Studio and Jim Woolcock, Suho Studio (SA)
- Sips and Sire by Chloe Overton (TAS)
- Bare House by Alicia Ferrer and Tristan Stanley-Cary (WA)
- Little Pot of Gold by Talina Edwards and Luc Plowman (QLD)
- True Blue Zero C02 by Lachlan McEwen and Melanie Lupis (NSW)
Size matters
Wheeler says although the tiny house craze has swept across the world in recent years it’s not what home builders and designers should be emulating – she says the craze is a response to a market in crisis.
Everyone deserves to have enough space to live comfortably in their home – but we definitely don’t need as much space as most people expect.
It’s a question of equity as well as carbon, she says.
“We need to be building much smaller. We cannot sustain building these enormous houses, it’s unconscionable,” Wheeler says.
The average free-standing house in Australia, according to CommSec’s latest Home Size Trends report, is 229.3 square metres. Apartments in Victoria are leading the way with the largest in the country at 156.8 square metres.
“There’s a lot of people out there who feel they need big homes to get the amenity they are looking for,” Wheeler says.
“I sought to test how small we can go.”
It’s impressive then that in the Omnia House, the designer has squeezed three bedrooms, a study, two living areas, two bathrooms, and outdoor storage in just 165 square metres – the same level of amenity than you would typically have in a standard design home, but in a much smaller footprint.
She says it comes back to cultural love affair with aesthetics: “We need to change the narrative – one of the biggest challenges for the industry is to change the [desired] aesthetic away from huge windows, huge spaces, massive open plan living areas.
“Omnia House doesn’t have any of those things, and that’s why it performs so well. That’s why it won.”
Tamar Boyd, who performed the thermal performance assessment on the building, said it is standard for aesthetics to come before energy efficiency – but this needs to change.
“Aesthetics, the look and feel are the most important thing. But at no point do we really talk about what the energy cost is,” she tells The Fifth Estate.
The low hanging fruit of building design
The house demonstrates effective passive design with north-facing orientation and smaller double-glazed windows, is well insulated and has surface-mounted downlights, and the colour options available for the roof and walls were selected to help with the heating and cooling load.
It achieves its NatHERS rating using EcoPact concrete – but if the home builder used timber, Wheeler said that embodied carbon would be less.
The easiest way to reduce carbon, she says, is to design a home that is all-electric, uses a heat pump and high-COP (coefficient of performance) air conditioning.
“I can’t fathom why in this century, given what we know, gas is even an option.”
Boyd says we need to have the tough conversations about energy and thermal efficiency at the beginning of the project.
“At no point is the general public educated on [thermal efficiency]… But if clients are actually serious about design and thermal performance, the cost of living, and meeting government targets, it should be part of the conversation.”
“Life is about compromising. You either compromise your budget or your ideal. Everything comes at a price.”
Part of this compromise is windows: another aesthetic obsession. Smaller than most homes built today, Wheeler says the ideal floor to glazing ratio should be 25 per cent in Melbourne, where heat is lost through the windows.
“Views are better appreciated when framed and made into a picture,” she says. It’s like only taking a slice of cake instead of the whole thing: it tastes so much better. And most people don’t have the luxury of a sweeping vista anyway.
Adaptability is key
Boyd says we need to tailor the home around the person living in it: “If you put a plant in the wrong room it will not thrive, it’s the same with humans”.
“[Wheeler] and I had a clear vision at the very start to not work on a project that was ostentatious and unattainable, inflexible, set in boundaries, we wanted a design that was livable and adaptable – and I think we achieved that.”
The home can be divided into two spaces if needed.
“If we facilitate ageing in place, people can stay in their homes longer, which is a positive,” Wheeler explains.
“But on the other hand, if they do, then in a large ‘family home’ they might be using more resources and land than is sustainable. The solution to that is an approach like Omnia House, which can work as two ‘apartments’, providing for multi-generational living and two households under one roof.”
The judges loved it, with Anderson commenting: “The way the house is cleverly set up for maximum flexibility of changing occupation over the years, including easy separation of the dwelling into two homes for extra rental income, or for a carer to live in enabling the owners to age in place without losing connection to neighbours and community.”
