If you are contemplating an eco friendly selfbuild project then it pays to be aware of where this whole process is going
Eco-house design is a fairly recent development which started getting off the ground in the UK during the mid 1990s.see more on background
Since then it has taken hold of the public imagination particularly through the printed media, the TV and internet, and has recently hit the mainstream exhibition world with Eco-Build at Earls Court.
It has recently been embraced by a few of the more forward-looking developers and builders and the government has been busy making statements about how all new housing will be zero carbonbit of a slippery fish. It tends to mean that a building uses no carbon (oil, coal, etc) to heat it (meaning in a 'net' way). It usually ignores the carbon which goes into building it (the embodied energy). See the page on Zero Carbon? in the near future. The building regulationsThese are the mass of regulations that cover safety, health, welfare, convenience, energy efficiency etc. in the way buildings are constructed. Not to be confused with Planning consent (which is more to do with whether you can put up the building in the first place) have tightened up a bit regarding insulation levels and every politician and architect claims to be a champion of the subject, whether they know anything about it or not. There are various (sometimes competing) sets of standards now in place by which buildings can be judged. The government and its agencies are busily producing publications to explore the subject.
It does seem that change is happening at an enormous rate and that if the government’s goal of all new housing in England being zero carbon by the year 2016 (and with Wales being even more optimistic!) there will have to be an unprecedented step change, not only within the building industry as a whole but also for self builders. However the present government is also ditching a great deal of its green agenda and according to to the Guardian Green-o-Meter, the last three years have seen a swing from “greenest ever” to “greenest never”
Some would ask whether the goal of zero carbon housing is possible on a widespread basis and whether a slightly lower standard like the Passivhaus standard is maybe a bit more realistic. When you look at web sites such as Zero Carbon Hub"The Zero Carbon Hub is a non-profit company limited by guarantee. We are a public/private partnership established to take day-to-day operational responsibility for co-ordinating delivery of low and zero carbon new homes" you realize that they are saying very little (check the links) and there is the suspicion that no-one is really committed to moving the process forward in the UK. Watch out for wriggle room.
Although you will probably end up using an architect or designer for your final plans there is no substitute for being clear about what you want. Especially with eco-house design, you may have to do quite a lot of research before you can get your design down on paper.
Essentially eco design has concentrated on the following areas:
- Conservation of energy.
- While it is being built (this is known as embodied energythe total amount of energy it takes to make a material (or a building). See more on embodied energy)
- During its lifetime
- On demolition
- Reduction of CO2Carbon dioxide is a gas which is given off when carbon based materials such as fossil fuels (coal, oil, and natural gas) are burned. It is called a greenhouse gas because it works like the glazing of a greenhouse and causes global warming emissions.
- Sustainability of building materials.
- Habitat protection.
- Avoidance of pollution.
- Conservation of water.
- Health and wellbeing of the occupants.
You, them and us
Green design of houses can fall into two categories:
- Design that is mainly beneficial to the health and wellbeing of the occupants.
- Design that takes into consideration a wide variety of ecological considerations.
While these categories can overlap and are not mutually exclusive it is worth being aware that they don’t always correspond with each other. Some examples of where they might diverge or overlap are as follows:
- The use of natural materials may be healthier for the occupants but may result in environmental damage or a high transport burden. Say for instance the use of real marble kitchen worktops.
- The use of sustainably produced timber can result in locking up carbon at the same time as being a pleasant and healthy material to live with.
- A log burning stove may have a low net level of CO2 output but may cause considerable air pollution.
- Recycled newspaper insulation such as Warmcell also locks up carbon, has very low embodied energy and contributes to the comfort of the occupants. Was an excellent use for NOTW.
- Living roofsA roof with a covering of soil or growing medium and plants. They tend to be divided into turf roofs with a 150mm layer of soil and sedum roofs with a thinner layer (about 40mm). see Living Roofs may improve the habitat for many species at the same time as providing a more visually interesting experience for the house owner and neighbours.
Apart from the huge amount of greenwasha term applied to deceptive or disingenuous marketing of a product on its green credentials. Based on the notion of 'whitewashing' things to make them look cleaner than they are, particularly from materials suppliers and commercial builders there is also a large imaginary area of greenness in the public mind and nowhere does it show up better than in the increasingly popular pastime of holding local environmental ‘open house’ days where people troop round each others houses looking at supposed environmental improvements.
While there are some excellent examples around, one is constantly coming across what is basically self deception held together by a mixture of ignorance, bad physics (ugh! – that word) and good intentions (road to hell etc.) There is a set of clue words and phrases which often give away what is going on. Here are a few:
our house only used xxx kilowatt hours of energy last year. Yes that’s because you sat shivering in dark rooms with 15 pullovers on all winter. Possible very commendable but this is about a change of lifestyle and nothing to do with building design. It’s like saying food has got cheaper because I don’t eat as much. You need to do proper calculations on the building.
log stove. ah yes that lovely ecological glow in the corner! But wait. A really well insulated house could not take a log stove. It would desperately overheat and you would have to leave the windows open. And have you checked whether it is legal? In smokeless zones (the Clean Air Act) there are strict requirements for a stove to be matched to the type of fuel, particularly the dryness of the timber, otherwise you are polluting your neighbours’ air with soot, tar and all sorts of dangerous chemicals. And then of course there’s heat stores, whether timber could be put to better use, how far it travelled, sustainability of wood fuel, route of combustion air, etc
heavy curtains. Heavy curtains to keep the windows and doors warm. This is probably one of the funniest of all. OK, curtains may cut down slightly on radiation losses (and so too will light curtains and low Erefers to glazing with low emissivity. A special coating on the glass prevents radiant heat escaping by reflecting it back into the room. glazing) but they will do very, very little for conduction losses and virtually nothing to stop drafts. You only have to sit near one of these heavy curtains to feel the cold air whistling under it and round the sides. Go on – try.
loft insulation. Oh you’ve only just heard about loft insulation.
some double glazing. Oh really, you’ve put some in? Well double glazing has been in the Building Regulations for new houses since the 1960s.
Kingspan. Kingspan (an excellent company by the way) makes a whole range of different types of insulation. Saying “We’ve installed some Kingspan” is like saying “we had some wine at the restaurant” Pretty meaningless and a dead giveaway.
Aga cooker. See here.
lovely warm house. Yes, is it because it’s well insulated or because you have a huge boiler going constantly?
natural materials. Oh yes marble all the way from India? Far Eastern plywood? Well concrete is natural isn’t it? It’s made from limestone which is natural. Anything we make is natural because people are natural and we naturally make it. Unless we are not natural, in which case, how did we evolve. Argh!!! A semantic trap.