Saturday, June 4, 2011

Good ideas badly implemented

Over the past few years we have been trying to get a new project off the ground. We are trying to convert our partly constructed barn into an “Interpretation Centre”. The term “Interpretation Centre” is not of our choosing. Construction projects in Victoria can only proceed if they are a “permitted use” within a particular land use zoning. We want to use our project to promote and teach Permaculture (topics to include energy efficient buildings, renewable energies, growing food, designing fire defences, sustainable behaviours etc). However, teaching facilities are not a permitted use in our particular zone, nor are host farms. After some searching we found the only heading that vaguely covered what we wanted to do, and that was “Interpretation Centre” – so that is what the project became defined as- on paper.

The planning scheme concept is an excellent idea. It aims to avoid inappropriate development eg. factories in residential areas, or high rise buildings shading out neighbours, or high density housing in conservation zones etc. To make sure clever developers do not “bend the rules”, all terms and concepts are precisely defined, and this has the unfortunate result of “locking out” good developments that do not fit the mould. Luckily for us there was an escape clause in the bureaucratic jungle and that was the magical term “Interpretation Centre”.

Of course bigger developers can often get around these restrictions because they have the resources (money) to spend on lawyers and planning staff who specialise in searching for ways to get around restrictions or know how to get them overturned.

The lesson we took away from this exercise was not to be put off by what looks like a barrier- dig deeper and you may find a way past the blockage.

The next hurdle we came across was Victoria’s 5 Star Energy Rating Scheme, which aims to ensure all new buildings reach minimal energy standards. Our planned “Interpretation centre” uses the same construction as our passive solar house, which has excellent thermal performance. Right now I am writing this at 10pm in June (early winter). The temperature inside is 19.8, whilst outside it is only 9 and we have not had our wood heater on for several days now. Even when it drops below zero outside, it never falls below 15 inside.

Generally we use our wood heater occasionally in May, more frequently in June, July and August and hardly at all in September. When we do use it, it is often just in the evenings and usually to create a cosier atmosphere when it is very bleak outside. The house does not need a lot of heating because of its large amount of thermal mass. The stored “heat” in the slab and internal mudbrick walls keeps internal temperatures from varying a great deal.

Our experience and the widely known performance characteristics of buildings of this type show that our “Interpretation Centre” will perform equally well thermally. We will be using very little energy to warm it (compared to conventional houses) and that energy will be renewable (using a wood heater) with fuel sourced from the forest area around our house (thereby reducing fuel levels for potential future wildfires). In summer, cooling will be via cross and stack ventilation. A well designed energy rating system would give our project full marks for its thermal performance and bonus marks because our systems are based on renewable sources. Not the Victorian system though. Its computer model takes into account the separate thermal performance of each type of building material, but gives very little consideration to the value of thermal mass. Nor does it appear to give adequate credit to other ways of reducing non renewable energy use such as shading of walls in summer, natural ventilation, using renewable fuel, gravity water systems, etc.

A quick way of evaluating whether the 5 star rating scheme is effective, is to measure the real life performance of some 5 star buildings. If they are using heaters frequently during autumn and spring or if they have an air conditioner, their thermal performance is questionable and so is the scheme.

So there we have it, two good ideas in principle but not always working too well in practice.
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