Solar Passive House Design, Malua Bay
This solar passive house is located in Malua Bay, just 10 minutes south of Batemans Bay on the NSW South Coast.
Named 'Dromhus', Swedish for Dream House, this eco house was designed by Paul Dolphin to showcase how an environmentally friendly house can be designed and built cost effectively.
The house has a solar passive orientation of NNW with optimised northern glazing and well considered shading. It was built on an insulated concrete slab on ground for thermal mass with several strategically placed thermal mass walls of concrete block. There is one face of blockwork in each habitable room.
The house is laid out so that the living room is to the West, bedrooms to the East. The bedrooms are generally 4 degrees cooler than the living which meets our habitable needs. The media room was purposely overglazed to the West, so that when the external shutters are taken off in winter, it can be incredibly cosy in there in the evening.
In summer, external shading as well as well-designed eaves exclude the summer sun. This means the internal thermal mass of the floor and the blockwork walls help to distribute the heat peak of the mid-afternoon. With its’ proximity to the ocean, most days during summer the afternoon change comes in. Once this blows, windows are opened and flush the thermal mass back down to a cool temperate for the next morning. The ceiling has vents into the corridor and bedrooms, and the windows open up both above and below the transom. This allows for stack ventilation as well as cross ventilation.
The external cladding is understated fibro-cement sheeting from James Hardie referencing the South Coast beach shack aesthetic - à-la 21st century eco-house beach shack. The windows and overall dimensions of the house were designed to the dimensions of FC sheeting, in 300mm increments. This reduced waste and gives a pleasing regularity to the visual form of the building.
The roof is Colorbond in a light color. The skillion roof form maximises solar harvesting potential while maintaining solar access to rear rooms.
The internal air quality is excellent with virtually no treated timber internally and low or zero VOC paints and sealers throughout. A Brayco stainless-steel kitchen provides a kitchen that off gasses no formaldehyde and also looks pretty neat!
“The aim of this house is to demonstrate how an eco house can be constructed using off the shelf products for a sustainable outcome. For example, the concrete block walls were the cheapest blocks you can buy, we simply sanded and sealed them. They are easy for a regular brickie to work with, so they are cheap to construct, but save huge amounts of energy on heating and cooling.
I call it the ‘eco middle way’. This house is sustainable, liveable and resilient. We have no energy bills, an edible garden, we heat the house occasionally with wood from the garden. In the bushfires we always had power from the battery and solar every time the grid went down. In the pandemic we have a warm house in winter with no energy bills, so as our income has been affected, we feel no bill stress.
We have tested the air quality in the house and it has incredibly low VOCs, low CO2 and low particulates. It was a nontoxic place to spend a lockdown.
Having used reclaimed and collected fixtures and furniture from around the world the house is great fun and a lot of joy to live in. It has been an inspiration for others and continues to be the template we use in our practice as building designers to inspire and share the joy and knowledge of sustainable living”.
DIRECTOR & PRINCIPAL DESIGNER, PdD BUILDING DESIGN
If you would like to know more about how to design an environmentally friendly house please sign up to our free webinar or Get in Touch! Paul Dolphin designs environmentally houses and loves to share his knowledge for free in these webinars. In 2020 his eco house won a national design award from the Building Designers Association of Australia.
This house won an award for New Residential Buildings up to 250 sqm and under $2,500/sqm. Read more about this here. The house has been opened for sustainable house day and will be open again follow this link for more updates.