On the drawing board: Two homes from one

In Canberra, Jenny Edwards and her team are becoming experts in conjuring comfortable dwellings for two or more groups of people from older homes that used to house just one.

“Where will your kids live when they’re adults?” With Australia facing the triple whammy of climate, housing and cost of living crises, this is a question I’m constantly asking my peers in an attempt to engage people on this rapidly worsening issue. As someone who has been working exclusively in sustainable housing for 15 years, and as parent to three young adults and employer of several young people struggling to enter the housing market (as buyers or renters), it is something that I spend a lot of time pondering.

It’s a complex problem and there is no one easy solution. Highrise apartments in cities and town centres – plus well-designed new infill builds in our suburbs – are part of the solution, but far from enough. We need to approach this problem from many different angles.

I strongly believe we need to get serious about renovating, retrofitting and repurposing existing buildings. We also need to increase housing density near existing services rather than continuing to develop more sprawling, low-density, infrastructure-heavy suburbs at the urban fringe, with their associated longer commute times, increased social isolation and biodiversity loss. However, that increased density doesn’t have to be limited to town centres. There is huge opportunity for gentle density in our older, established suburbs.

In our experience at Light House, there are multiple ways to change a regular suburban house and block from one that is suited to just one household group to one that could comfortably provide a home for two or more groups. These are the approaches we have used and would like to encourage others to explore:

1. 1. Convert the existing home into two homes in one, without any extension
   2. Convert the existing home into two homes in one with a well-designed, space-efficient extension
   3. Build a separate secondary residence
   4. Combine approaches 1 and 3
   5. Where the existing home is so poorly constructed or positioned on the block that starting again makes sense, demolish (salvaging as much as possible) and build two or more compact, efficient homes on the block.

Instead of defaulting to the notion that old homes must be knocked down to allow construction of two or three modern (often cheaply built, minimum-standard) homes, how about we first thoroughly investigate what is possible with the existing home and site? In this article, I’ll present three Light House projects that cover the first two approaches (which are my favourites!).

Evolution House

Originally a modest 116 square metres with four bedrooms, this 1970s home in the Canberra suburb of Kambah was extended in the 1980s and again in the 1990s, resulting in a rambling, energy-guzzling 214-square-metre house.

Our client bought the property 20 years ago as a family home. A decade or so later she found herself with an empty (and terribly inefficient and uncomfortable) nest and way more space than she needed.

She came to us in 2021 with a fabulous idea. Could we turn this well-orientated, solid but oddly configured and leaky, big house into two modern energy-efficient homes? Yes please! This is a dream brief for Light House. Repurposing an existing building to house two groups of people while massively improving the thermal performance ticks so many boxes for us – environmental and social sustainability, space and energy efficiency, health and biodiversity, low embodied carbon, low operational carbon … win-win-win.

Wendy on life in Evolution House

“I think my space is a great example of how less than 70 square metres can provide a comfortable, attractive and easily maintained living space for one or two people. My daughter, son-in-law and two grandchildren now live in the other home created from my big old house. The redesigned residences and cohabiting arrangement have many benefits including:

• Spaces that are tailored to our needs: my studio is the same size as an apartment but without strata fees, while the main part of the house is still larger than an average sized ex-government house in Canberra.
• Homes that are far more comfortable to live in, with upgrades to insulation and windows (previously the house was very cold in winter and stifling hot in west-facing rooms in summer).
• Housing stock freed up for others: the renovation was funded by selling another house, and my daughter and son-in-law now have a much smaller mortgage.
• Reduced expenses for utilities and rates, home and contents insurance, internet connection and rubbish collection, as these things are shared.
• Shared maintenance of our homes and garden (we draw on our different skills and interests).
• Shared access to generous outdoor areas, vegetable garden, shed, tools and two-car garage; between our households we have a medium-sized and a small car, and use each other’s cars if the need arises.
• Daily social interaction, communal shopping and readily available care for children and pets (two dogs and four cats).

We had a solicitor draw up a Deed of Family Agreement, a legal document that sets out and protects our financial interests.”

Mentha House

A few suburbs away in Rivett, an existing 106-square-metre, 2.4-Star, 1960s home is in the process of being extended by a very modest 38 square metres to create two 7.7-Star, all-electric homes in one.

The project will result in a one-bedroom home with two bathrooms and a generous study and multipurpose room, all in a footprint of less than 100 square metres, for our clients to downsize to and comfortably age in place. Taking up the western end of the building, a one-bedroom studio of just under 50 square metres – with a bathroom and a compact study – will provide accommodation for a family member, a tenant, or (further down the track) a live-in carer.

If the house was to sell in the future, it could function either as a generous, comfortable and energy-efficient family home of 144 square metres, or as two smaller super-sustainable residences.

Chook House

Across town in Lyneham, the family (including two teenagers) living in this 110-square-metre 1960s house were crying out for more space, so we designed them a 47-square-metre extension – and rejigged the existing layout slightly – to create a bigger and more functional house to suit their current needs.

The existing, perfectly orientated home had already been draught-sealed and thoroughly retrofitted with insulation and quality glazing to lift its energy rating from 4 Stars to over 7 Stars. The extension enhances rather than undoes any of that great thermal work (existing triple glazing is being reused in new locations), and the new design rates at 7.7 Stars. We’ve also taken the opportunity to disconnect from gas and go all-electric.

Clever design means that down the track, the extension can be used as a separate one-bedroom studio for a tenant or independent family member – or perhaps the parents will move into the cosy, compact studio and rent out the house? Flexibility for changing family needs and multiple groups is the key!