Warm temperate passive solar

This home (under construction) is at Leeton, NSW, in the heart of warm temperate semi arid climate. Summer is hot (maximum 450C) and winter is cold (minimum -30C).

The Brief

We are a couple in their early 40s with three children – aged 10, 12 & 14. We live modestly and plan that this house, will be a long term investment in family and lifestyle. We enjoy the outdoors and simple living. We dislike dark, closed in spaces and therefore want our home to have a lot of natural light and fresh air.

We are not wealthy and prefer to spend on the structure and function rather than the finishes.

We need a designer who;

  • Understands energy minimisation strategies – thermal mass, construction, location, material choice, energy options (solar, LED etc), colour choice
  • Thinks along the lines of http://www.yourhome.gov.au philosophy
  • Can think “outside the box”
  • Has dialogue with us and can discuss ideas and solutions
  • Can draw up plans including the necessary materials, specifications and construction to ensure the integrity of the house function is maintained eg. double –glazed window, insulation rating/materials etc. by the builder.
  • Understands our financial capability.

The process

I caught the train out, set up the laptop on their dining room table for a few days and we designed the house together.

3D software was invaluable here for quick design and visualisation. So too was good old pen & paper.  At one point we were stuck on some design problem and decided to sleep on it – but not for long. Mum woke in the middle of the night to sketch the solution on tracing paper. Welcome to the life of a designer. By the end of the trip, we had a concept we were all happy with.

The design

A lot of time went into measuring rooms and the spaces are the right size for the family and work the way they want them to. There is plenty of storage, a communal family area, a rumpus room for adults and kids to separate, and a kid’s sleeping wing. If the kids end up leaving home, the kid’s wing can be isolated thermally. Artificial cooling or heating can be restricted to the rooms that are used.

We’re hoping there won’t be too much of that. The walls are heavily insulated, with stud frames insulated by high density batts, with an additional battened cavity space, over which is thick polystyrene cladding. Thermal mass is in the form of a concrete floor insulated at the edges with polystyrene. There is more insulated thermal mass using internal walls of brick or gravel filled concrete block. The roof is heavily insulated at two levels, a blanket directly under the roofing and batts above the ceiling. Windows and doors are double glazed with thermal breaks. The windows to the north have fairly low sills for winter sun penetration. Metal & polystyrene sandwich panels can be fitted externally over the windows for cool summer shade. We thought about using deciduous pergolas and courtyards, but the owners ended up scratching that because of potential mosquito habitat fed by the nearby wetlands.

My clients want to live here forever, so the doors, bathroom and kitchen are compatible with elderly people with mobility restrictions. This sort of thing costs little to build in the first place, and much more to retrofit later. It’s yet unclear what dad is most excited about, his first own home or the truly man sized shed to play around in.