Prototype builds using these simple materials have shown that it is possible to reach PassivHaus standards of airtightness without the need for membranes, tapes or sealants. Unfired clay masonry has been shown to provide passive environmental control in buildings through the buffering of temperature and relative humidity.
Earth blocks and plasters are made from simple materials; clay rich earth and straw, but are also simple in their construction method. Any mason or block layer will be familiar with the process of laying them and any plasterer will be familiar with methods employed to use plasters.
As your house heats up through the heating system or solar gain the earth heats up and stores thermal energy. When heat starts to flow out of your building, perhaps the heating has been turned off at night, the stored heat starts to discharge into the room passively warming the space. This creates a more even internal temperature between day and night and reduces the load on your heating system, decreasing fuel bills. As you are storing thermal energy in your walls not just in the air, you can perform the required amount of air changes with fresh external air without losing your heat store. This makes cheap and simple natural ventilation a viable option
Where is the material sourced and produced?
The timber is grown across 70-80 forests in Poland, and the products are produced in two polish factories. How sustainable is it? The timber is sourced from FSC certified forests. The main timber species used are Picea Abies and Pinus Sylvestris Following manufacture in Poland, the timber products were sourced from Alsford Timber in Kent.
Straw bales are tightly packed and covered with a skin of render. Fire can’t burn without oxygen, and the dense walls provide a nearly airless environment, so the fire resistance of compacted straw is very good. Strawbale homes survived Californian bush fires that destroyed conventional structures.
Straw bales also provide cost effective sound insulation, which contributes to the liveability of this kind of construction and can be quite marked. Even walking into the space created by an unfinished strawbale structure, one can appreciate the quietness and hear the difference from conventional buildings.
Timber I-Joists should be protected from the elements and particularly protected from excessive exposure to moisture. They should then be installed internally.
£6.55 / metre 60x400x12000mm
£5.80 / metre 60x240x12000mm