jan_ladhams' ideas
An airtight, insulated building will successfully retain any warmth or coolness generated within, which is, essentially, why these houses require so little energy to heat or cool. Because the building is airtight, and all draughts and air leakages are precluded, the flow of air in and out of a passive house is controlled with a heat recovery ventilation (HRV) system, which is the fifth design component. The HRV is pivotal to the functioning of the passive house, flushing stale air out and replacing it with a constant supply of fresh, temperature-controlled, filtered air. It stops the house from getting stuffy, improves the overall air quality, and, in cold weather, prevents the build-up of condensation. Crucially, the HRV incorporates a heat exchanger, so incoming fresh air is almost the same temperature as the air that’s being flushed out. “In this way, 85 to 90 per cent of the energy that’s in the house you can keep in the house,” Bernstein Hussmann says. “Once your house has reached its optimum temperature of 22 to 23°C, it’ll just stay that temperature forever. That’s the idea, that’s how it works.”
High-quality windows and doors “Then we need really good windows to go with that, because you don’t want to lose all your energy through the windows,” Window frames must be well insulated, and fitted with double glazing or low-emissivity glass. Tip: Low-emissivity or low-e glass has a very thin coating that reflects heat. This is great if you want to block hot western sun, for example, but may compromise winter heat gain if used on north-facing windows in solar passive homes. The building needs to be airtight so there are no draughts of cold/hot spots in the house.
The Principles of a Passive House While a passive house won’t necessarily look any different from a ‘normal’ home, there are five key differences in the way it’s constructed. 1. Insulation “When building a passive house, the first thing is you create a highly efficient building envelope that’s very well insulated,” says Marc Bernstein-Hussmann, director of Melbourne Design Studios and certified passive house designer. Passive houses are wrapped in a ‘blanket’ of insulation; it’s used in the walls, floor and ceiling. Alternatively the home will be built from insulating materials, such as aerated autoclaved concrete (AAC) blocks, prefabricated foam panels,
Ian talks about the reconciliation of biodiversity and bushfire with human habitation. I believe this is achievable in a sustaining and caring way. I have been going to Hopetoun for over 50 years and it is where I want to wind down for the rest of my days. I believe Ian may be able to help me achieve my dream of creating a green, sustainable home design that will have a minimum impact on the fragile biodiversity of the area I have love practically my whole life.
Permaculture practices, including reusing all waste on site, have been incorporated into the design. “Our garden feeds us and we feed the chooks with scraps, which in turn gives us eggs and fertiliser for the garden,” says one of the owners. “Similarly, the fish deposit nitrogen in our pond, which feeds the bacteria on the clay beads in the vertical garden, which in turn feeds the plants, which filter the water in a continuous cycle.” The chickens are housed in a coop on one side of the garden that is integrated with onsite storage and a worm farm.
In the rear garden, outdoor seating doubles as an aquaponics system for fish waste harvesting and fertilising the vertical lettuce garden that runs along the entire wall behind it. The owner’s interest in permaculture drove the design of the rear garden. “The garden acts as a social hub, with visitors being drawn subconsciously through the home and outside to sit among the plants and the chickens. Productive gardens are always changing and somewhat unpredictable but this adds to our enjoyment,” says one of the owners. “Somewhat unexpectedly, a papaya grew out of our compost last summer and has given a tree burgeoning with ripe fruit!”
I live in a passive solar designed house built in the 1965 and extended in 1970. It has minimal windows facing south, all doorways face east, or north. The sun room extension faces northwest, which in Ballarat's cold winters ensures maximum heat gain, whilst eaves are designed to shade out the sun in summer, from north facing windows and doors. Awnings are fitted on east and west facing windows. I do not need any form of summer cooling except for the very exceptional day, where I switch on the ceiling fan. The home is well insulated but, thankfully, not 100 per cent sealed. I actually like to open windows and doors to let in fresh air and have found fully passive designs to be a somewhat oppressive and airless, as the occupants never seem to open anything up. They remain cold in winter in Ballarat, without some form of heating. I have retrofitted argon filled double glazing on all my eastern and south facing windows, costing me many thousands of dollars, as the windows are enormous. My house pretty much runs on solar power system and solar hot water and my power bills are minimal. I believe a home's orientation in Australia is vital. Having lived in houses with northern orientatio...
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