Wednesday, 10 August 2011


Perhaps it's having studied engineering but in a lot of places I'm looking for optimisation. House building is full of compromises, often between material cost, installation cost, appearance, functionality and energy efficiency. Maybe sometimes between the egos and prejudices of the various players. Energy efficiency usually comes last on people's lists, if at all, although I'm sure recent marketing must be having some influence. Perhaps we'll have to wait another twenty years until the children being exposed to it are practicing architects. 

I feel I scored a great victory in persuading the electrician to run the wires from the power conditioners, which convert the DC from the solar panels into AC for the grid, straight down the wall to the distribution board. Both the power conditioners and the distribution board are on the same wall, facing South in the middle of the house. The distribution board is a metre or two from the East wall on the ground floor; the power conditioners a metre or two from the East wall in the loft. The shortest distance between two points is a straight line, and this one is vertical. Upstairs, between them, is the bathroom. In the original plan, the wires were to circumnavigate the bathroom, adding at least a metre to their length.

A metre is probably not a big deal, although the current has to get through whatever resistance there is in the wires and will lose some of the power, and there will sometimes be over 9 kilowatts. Financially, the important distances are from the panels to the power conditioner, and from the power conditioner to the electricity metre. There are two electricity metres, one counting the electricity we buy, the other counting the electricity we sell. 

It's more a matter of principle, and if it's possible to make it shorter, then it should be made shorter. 

The problem is, people are all busy doing their jobs. The architect's job is to draw lines on paper, and the more lines he draws, the happier he is! The electrician puts in wires, the plumbers put in pipes. The cost of pencil lead, wire and piping is relatively small, and the client is going to pay for it anyway.

We have spent hours thinking about where we want each sink or basin, and where the electrical appliances and outlets should be, and we will spend years using them and living with the consequences. For the plumbers or electricians, it's just another hole to drill in a wall or a floor.