Plot 14 - Anna and Jackson
Jackson writes:
We set out from the start to try to build a house that has minimum impact on the environment, both during the build and once we are living in it. This involved a number of broad issues:
1) Using locally sourced materials. This reduces the energy required in their transportation to the site.
2) Using materials that have low embodied energy (the energy required to produce the product). Cement has high embodied energy, but we have minimised its use by building with a timber frame. However, we did have to use cement in the concrete for the foundation work.
3) Using materials from renewable and recycled sources. We have used timber for the frame and recycled newspapers for insulation.
4) Using socially acceptable materials. Most softwood timber is called sustainable because it is replanted for future harvests. However there are many other issues relating to forest resources, based on social, economical, ecological, cultural and spiritual needs. Obtaining FSC* timber is a way of encouraging the timber industry to recognise these other issues. Having been turned down by all the large timber merchants in Bristol (even the ones that promote FSC timber) to source structural FSC timber for the frame of our house, we contacted the Forest Stewardship Council for timber mills in the UK. On providing these details to Lathams, they agreed to obtain some structural grade FSC timber for us from Scotland.
5) Maximising passive solar heating. We have increased the amount of solar energy entering the house by using large glazing on the south side. You can see from the photos below that light will come through the four large windows facing due south and will reach right to the back of the house. There will be a shelf above these windows to hold the solar photovoltaic panels which will also shield the windows in the summer preventing over heating.
6) Minimising energy loss. There are no windows in the north side of the house and we have used glazing with low u-values (below 1.5 W/m2K), and Warmcel** insulation 200mm thick in the walls and 300mm in the roof. The frame, which is made of 150mmx50mm studs, is cross battened internally with 50mmx50mm battens to reduce cold bridging, prior to Fermacell or plasterboard. The house will also be semi-detached to the house on the north side, again reducing heat loss.
7) Using healthy materials and paints. We want to use paints with minimum or zero VOC (Volatile organic compounds). These not only evaporate into the atmosphere when the paint dries, but also leach out over time within the house. We have not got this far yet, so any ideas will be greatly welcomed!
[back] * The Forest Stewardship Council (FSC) is an international body whose goal is to promote environmentally responsible, socially beneficial and economically viable management of worlds forests. To find out more about FSC and their principles, see http://www.fsc-uk.info/principles.asp.
[back] ** Warmcel is made from recycled newspapers. See http://www.warmcel.com/.
(Click on pictures for larger version.)
Plot 1, Plot 2, Plot 3, Plot 4, Plot 5, Plot 6, Plot 7, Plots 8 and 9, Plot 10, Plot 11, Plot 12, Plot 13, Plot 14, Plot 15, Plot 16, Plots 17 to 20, Plots 21 to 26.