Iris House (Affordable Sustainable House #1) 2023

House Notes – Iris House (Affordable Sustainable House #1)

In May 2017 I had zero dollars, but I had a new job as a graduate planning officer in a rural Shire in Victoria.

I was a single parent with one son. I was determined to finally have my own house, with a minimum 7.5 NatHERS rating.

I had been interested in sustainability for a long time, and I lived without a car, which saved me money. I was able to get a loan for a small block of vacant land in a country town.

For over 2 years, the project was in the planning/design/costings phase, as I worked to achieve a high-rating design within a construction budget of $200,000.

I chose a builder who specialises in modular construction of prefab dwellings, and was supportive to my requirements – Bond Homes in Wendouree, Victoria.

With the learning resources listed below, I started with a simple off-the-shelf design and turned it into a passive solar house by:

– Re-orientated the building design, turning it back-to-front, but offsetting at an angle from the street, so that the living areas would face 10 degrees east of north.

– Added eaves on the north, and redesigned the internal spaces, to minimise wasted corridor space and to optimise winter sun as deep as possible into the living areas.

– Designed it to have thermal mass made from wine bottles stacked up on the living room walls, with reinforced sub-floor, thus saving the cost of a concrete slab.

– Had the specifications upgraded, so that it became very well insulated with a well made building envelope, with a blower door test from ‘Efficiency Matrix’ before handover.

– Specified all-electric fittings, including induction cooktop, heat pump for hot water, and heating/cooling with a single 5kW RCAC unit.

Installation after construction:
– Honeycomb blinds
– Liquid thermal mass
– 10kw PV system
– North-facing deck and pergola to support vines
– Landscaping

Result = Zero annual power bills!

My resources:

– Sanctuary magazine,
– Renew magazine,
– the government resource Your Home,
– the brains-trust of the many members of the Facebook group ‘My Efficient Electric Home’

The Iris House has a full episode in Season 3 of ‘The New Joneses’ www.thenewjoneses.com
The New Joneses shoots 10 episodes each year since 2021, 10 mins each, with lots of resources on their website.
Season 3 dropping in May 2023.

The story has been documented, warts and all, on the house’s Facebook Page ‘Affordable Sustainable House Single and Happy’ – check it out!
https://www.facebook.com/AffordableSustainableHouse

This house achieved a NatHERS rating of 7.7 stars using NatHERS accredited software.

Find out how the star ratings work on the Nationwide House Energy Rating Scheme (NatHERS) website.

Photos by Helena Wilson.