Sustainable House - Retrofit Farmhouse
Updated: Oct 7, 2018
By Wendy & Ken Savage
Our house is a weatherboard farmhouse built in the 40s from local timber milled nearby. It had not been designed or sited for passive warming or cooling and was cold and draughty in winter. To make it more comfortable and sustainable we have improved it in the following ways over the last 34 years.
Removed the weatherboards to put insulation and sarking in the walls
Installed fibreglass insulation batts in the ceiling, and recently placed wool batts on top
Built verandahs around three sides for shading and heat loss reduction
Planted the garden with shelter plants for wind reduction. The house was originally surrounded on three sides with huge cypresses and pines, which funnelled the wind underneath them.
Installed underfloor concertina foil insulation and shadecloth around the outside stumps to cut down air flow
Retained carpets for warmth and put internal roman blinds in main living area. Unused rooms are closed off on winter evenings. Roman blinds are on order to be installed in the bedrooms.
Reduced the gaps where cold air could enter in winter (and made the house mouse-proof at the same time)
In 2014 we had Magnetite retrofit double glazing fitted to all the windows, and the process includes sealing all window and door frames for draughts
Replaced the open fire with a more efficient Jetmaster insert. We close the flue when the fire is not in use to stop the warm air in the house escaping up the chimney
Installed a solid fuel wood heater in the extension
Wood is sourced from a renewable wood supply planted on the property – we have planted many more trees than we will ever burn, so we consider this a sustainable energy supply
Planted deciduous trees around the house for summer shading and cooling by transpiration. Verandahs and trees keep sun off all windows in summer.
Have opening windows on all sides of the house for rapid cooling on hot summer evenings
Installed a 2.3 KW Photovoltaic grid connect system in 2007
Cut our electricity use to around 8 Kwh/day by taking hot water off electricity, installing energy saving lights and changes in behaviour
Hot water is produced from solar panels, a wet back on the Jetmaster and a flue jacket on the solid fuel heater. We have a 30 year old 360L copper storage tank in the ceiling so water movement is by passive thermocycle – no electric pumps are needed.
All water is collected in tanks and grey water can be connected to a watering system for the garden in times of drought.
Home Sustainability Assessment
This was done in January 2017 by the BBSN (Baw Baw Sustainability Network) and included a measure of air leakage using a Blower Door.
Our house had 16.5 Air changes per hour @50Pa (pressure used for the measure)
This is not good – between fair and bad on the chart.
We were also given a thermography report where an infrared camera was used to show where heat was being lost either through air leakage or gaps in insulation.
Since then many leaks have been sealed using an acrylic gap sealant, such as around doors, windows frames, skirting boards, skylights etc.
Victorian Scorecard Assessment
This is a star rating on your house and is delivered by independent accredited assessors using the government-supported Scorecard webtool. The assessor rates the energy efficiency of your home's construction, fixed appliances, and other key features such as solar PV energy production. The Scorecard also rates how comfortable your home is in hot weather.
We had this assessment this month and we rated 6 stars out of 10. I imagine when we first moved into the house it would have been about 1 star.