About KC Natural Homes
The average person in this country spends 90% of their time indoors & indoor air pollution has been identified as a serious environmental risk to human health. Current building industry standards do not place a high priority on avoiding toxic materials. Also, the high cost of heating & cooling our homes necessitates a more efficient building envelope, which can be better obtained with natural healthy materials.
What do you mean by a healthy, natural home?
There is a lot of hype about green or natural building these days. A natural home is one built with minimally processed, locally sourced materials with low environmental impact & designed with the health of the occupants kept foremost in mind.
How is a natural home more healthy than a standard modern home?
Most people spend the majority of their time indoors and indoor air pollution has been cited as a major cause of modern health problems. Often, the finishing materials in our homes have been chosen with no regard for human health. For example, off-gassing from glues, paint and synthetic carpets can negatively affect the health of the home’s occupants. The concerns about water damage & mold in our damp climate have led to the practise of sealing everything up inside a continuous plastic vapour barrier, which leads to problems with ventilation and generally exacerbates the health problems. In our damp coastal climate, it is important to allow the outer skin of our buildings to breathe. Researchers in Northern Europe have developed a method of building walls with clay and straw which provides thermal mass and insulation, while allowing diffusion of water vapour through the wall. Known as “light clay” construction, this wall system can also be built with clay and wood chips, which are more readily available here on the coast. When finished with natural clay and lime plasters or wood siding, these walls can be very beautiful and provide a warmth and feeling of tranquillity indoors, which needs to be experienced to fully appreciate.
The fireplace in the centre of the home is quite impressive and looks different. What is the story here?
Another element of natural building to consider is thermal mass and radiant heating. A centrally located contraflow masonry heater fireplace will provide radiant heat with only one fire per day. A quick hot fire warms a large mass of masonry, which provides radiant heat throughout the night and into the next day. The main idea is an unimpeded supply of outside air for combustion and a somewhat convoluted path for the exhaust gases, to transfer as much of the heat into the masonry as possible before exiting the chimney. Properly designed and operated it is a very efficient and minimally polluting heat source.
What other design elements help this home to be energy efficient and comfortable?
All our energy ultimately comes from the sun, so it makes sense to orient our homes with more south facing windows and wide overhangs to take advantage of the low winter sun and block some of the high summer sun. Natural homes also feature in-floor radiant heating supplemented by solar collectors
What holds the home up? Surely the clay-straw walls aren’t structural…
The home is constructed using a braced timber frame, using traditional mortise-and-tenon joinery. The exterior walls are framed with Larsen trusses made from standard framing lumber and sheathed with temporary plywood forms. The straw-clay mixture is packed between them, the forms are removed (to be re-used as roof sheathing) and the walls are allowed to dry, then finished using natural wood board-and-batten siding on the outside, and natural plasters on the inside.