Safe and sound

Insulation, secondary glazing and draught sealing have economically transformed a chilly, noisy weatherboard house into a snug and peaceful home.

Front of house

It’s always strangely comforting to hear that experts make mistakes too. Architect Sarah Fiess and her partner Marcus, an IT consultant who works from home, are clearly delighted with the results of a recent home renovation that Marcus project managed. But both say that, even with Sarah’s professional experience helping others renovate sustainably and the hours Marcus devoted to product research, they learned plenty along the way and would do some things differently next time around – especially wall insulation, which has left them with damage to fix inside and out. “I lead the ‘Smarter Renovations’ project and understand all the concepts, but even simple things like insulation can be difficult to get right in old, imperfect houses with all their idiosyncrasies,” Sarah says.

Marcus hails from Germany so had no experience of energy inefficient weatherboard homes when the pair bought their Yarraville residence in May last year. Sarah admits even she underestimated how much tricky retrofitting would be required to turn the draughty, poorly insulated place (which they discovered lay close to an occasional flight path) into a quiet, well sealed, energy efficient home. “What we liked about this place was that we thought there wasn’t too much to do,” Sarah recalls with a laugh. As soon as they moved in, however, they discovered the interior was “horribly cold”.

Ducted heating proved costly and inefficient due to a poorly positioned hallway thermostat that left most rooms chilly. Roof insulation was old and patchy. Windows and doors were poorly sealed. Walls contained no insulation, despite a 2006 brick renovation to the rear that could have added some. The previous owners had, however, introduced solar power and hot water and rainwater tanks. Huddled beneath sleeping bags in their icy living room, Sarah and Marcus began planning economical improvements to increase energy efficiency and reduce bills and noise.

DIY draught sealing to internal and external doors was an ultra cheap ‘no brainer’ that worked a treat, trapping heat and repelling noise. Sarah and Marcus enlisted a company to add secondary glazing to 11 windows. It cost a fraction of the price of double glazing and they’re understandably pleased with the results. Lightweight acrylic panels sit 100mm off the original glass panes, adhered via magnetised frames. They’re so subtle they’re hard to spot, and have allowed Sarah and Marcus to retain the home’s original timber window frames, whose character they like.

Halogen downlights were replaced with LED lights capped in the roof cavity to safely trap heat and allow insulation to sit flush against them. Well sealed, double glazed French doors and a powerful ceiling fan were installed in the rear living room, where the sleeping bags have been packed away for good.


Insulation proved trickiest and most expensive. DIY plans to add R5 insulation and foil sarking to the ceiling were dashed by a manhole that only allowed access to the roof cavity above the master bedroom. Marcus found a contractor willing to install ceiling insulation by temporarily removing not just the roof but the solar panels and hot water service on top. The total cost ballooned to double their original estimate.

For the walls the pair opted for spray foam insulation, applied via holes drilled into internal walls. It expands inside the wall cavity and retains its R value better than regular batts, which shrink over time. In retrospect, both agree the more expensive option of removing weatherboards to fit regular insulation would have delivered a better result. The contractor took two attempts to achieve even coverage and Sarah and Marcus now have high rows of holes in most walls to patch and paint. Outside, painted weatherboards have started to bubble due to moisture released from the wall cavity.


Hiccups aside, the renovation achieved the acoustic and thermal improvements Sarah and Marcus craved. Their house now stays comfortable in summer and winter largely via passive solar means, except on extreme days when occasional 15–20 minute blasts of heating or cooling are required. Their tips for anyone contemplating similar measures? Do your research on products, ask detailed questions of people who have done something similar (websites like and are good places to start), and choose contractors carefully, quizzing not just the sales reps doing the quoting but the tradespeople who will undertake the work. With sustainability still far from the norm, it’s crucial to brief all tradespeople on exactly what you want and be sure whoever you choose is experienced. “Ask to see some examples of their previous work or contact a previous client,” Sarah advises. “That’s what we do with builders in the architecture world.”

Text: Kath Dolan

Photography: Roma Samuel

Prepared with assistance from Green Magazine

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Smarter Renovations profile – Safe and sound

Insulation, secondary glazing and draught sealing have economically transformed a chilly, noisy weatherboard into a snug and peaceful home.