One of the first homes that I was asked to build, under an ‘eco-friendly’ banner, called for naturally durable non-treated timber and locally sourced materials. This was a home designed by a Building Biologist and to be located near Hamilton around 23 years ago. The design also called for no steel to be incorporated in the construction of this dwelling (something to do with electro-magnetic fields and a faraday cage). This meant wooden nails and time consuming housings in the framing, plastic or polypropylene reinforcing in the foundations. Aside from some of the design boundaries being, arguably, a little misguided in regards to green/healthy homes, the project’s ethical ideal, admirable as it was, was doomed due to the cost to build going outside of the client’s capability.
This type of situation typically leaves a designer disappointed with their creativity unrealized, the client disillusioned and the public perception that building healthy or green is unaffordable.
Compromising with a few kilos of nails would have made a big difference to the chance of seeing a home built with some very relevant ‘green’ features.
Over the years I have been designing and building healthy/green homes I have had to assess the value of compromise vs. no compromise. One good example is the use of cement in the construction of rammed earth walls. Cement is seen as being high in embodied energy, which counts against its ‘greenness’. Embodied energy is defined as the sum of energy inputs (fuels/power, materials, human resources etc) that was used in the work to make any product, from the point of extraction and refining materials, bringing it to market, and disposal / re-purposing of it.
Ideally we would like to use no cement in our rammed earth walls, or at least not cement in its current high-embodied energy form. We already know that it is possible to produce durable rammed earth walls with little or no cement, but the problem here is that it is either prohibitively expensive or far more extensive research and testing is required.
In the meantime I don’t have the research budget to discover the cement free solution.
The important thing at this stage is to keep getting rammed earth walls constructed and therefore achieve more exposure in the public domain, keeping the option of rammed earth homes up on our collective radar. To do this effectively we need to insure that the walls we do build wont fail and that they outperform conventional wall construction (which incidentally shouldn’t be hard considering the rotting building crisis that is currently crippling our building industry).
The more rammed earth walls that get built the greater the collective research budget will get and greener solutions will come. We would struggle to get this result without compromise.