Efficiently owner-built: A warming tale

Efficiently owner built

Location, communication and efficiency are three key parts of this owner-build—along with an innovative hydronic heating and cooling system. Cathryn Hamilton describes the process and results for her house in Adelaide.

Owner building is all about communication. Well, at least for us it was, as we were project-managing owner-builders, rather than actual builders. Our main tasks were finding good tradespeople and coordinating them. It was great to be in control of the project, but it was also hard at times, and mistakes were made. But we love the end result and the house works exactly as we’d hoped.

What did we hope for? Our house building project began when my husband John and I became empty nesters and realised our six-bedroom home at the time would be much better used by a larger family. We also wanted to live closer to our jobs, to avoid long travel times and the consequent fuel use and transport footprint. But perhaps most importantly, we’d also spent time in the UK and Europe and seen just how efficient buildings could be, compared to our draughty, poorly insulated, single-glazed home.

We quickly realised we’d need to build rather than buy to get what we wanted at that time in Adelaide. In 2010, we found a 400 m2 corner plot, facing north-east, in a spot convenient for both our jobs, which we snapped up.

Soon after, we got the opportunity to participate in a university project. Architecture and construction student teams designed a home to meet our requirements, working with a budget of $350,000. Although the student designs didn’t quite fit the bill, it was a helpful exercise in working out what we really wanted—and in realising that our budget might need to be higher. The build ended up costing us almost double that original budget, due partly to the new technology we employed and the build quality we wanted.

A design for energy efficiency
The design process began in earnest in April 2011, when we discussed our plans with architect John Maitland from Energy Architecture. We’d met John previously when he opened his house on Sustainable House Day [Ed note: In a nice twist, Cathryn’s house opened in 2017 and is opening again at this year’s event on 16 September; see www.sustainablehouseday.com].

We’d liked John’s ideas about appropriate orientation and passive heating/cooling, using thermal mass combined with a hydronic system to maintain stable temperatures.

Our brief to him was for an energy-efficient home which would capture as much rainwater as possible for use in the home; the latter was particularly important to us in Adelaide’s dry climate. We also wanted a home that could age with us. We wanted wider doorways and ramps, and a ground floor that allowed for all daily activities (we needed a partial second storey given the small footprint).

Read the full article in ReNew 144.