Sunday, 26 May 2013

Stop beating arround the bush!

We need action and progress!
No diluting and digressing!

This telegraph article on "The low-cost family house of the future" is a prime example of the hot air our society and precisely lobbies of all kinds of industries are producing, obviously trying to avoid progress threatening established margins by all means.

The article is all about low-cost and low-energy but it avoids the slightest, in fact any reference to real numbers; as such those terms remain as accurate as the coordinates of cloud-cuckoo-land, obviously just another exercise to fill the paper and irritating the public.

Cost in relation to home building regularly comes as £ per square metre [£/m²] and low-energy refers to gobbledygook unless you define the energy consumption; internationally that is done in kiloWatt per square metre and year [kW/m²a].

There is, oh wonder oh Telegraph, an international Standard, supra-nationally now accepted in many countries, from Japan to the US, from Norway to South Africa, in Australia and in South America: it is called Passive House Standard; it defines the maximum energy consumption to be no more than 15 kW/m²a* for the space heating demand. To get there it needs a thorough calculation taking many different factors into account not only the construction's location and orientation but also all materials', all components' and all appliances' energy efficiencies; the software developed to do exactly that is called PHPP, the Passive House Planning Package.

Solar gain and lunar loss, air-changes per hour [ach], air tightness, U-values, thermal conductivity, thermal bridging, psi-values, efficiency values those are the modern parameters to take into account. Quite a difference to living in caves or cavity-cold homes.
So it is time to stop producing hot air, time to end this useless inventing British complicated but diluted standards that no enduser will be able to understand (> CoSH); no need to invent any more British wheels again and again; what is needed is for all members of the British construction industry, from the bosses down, to (want to) understand that it is high time to apply this existing and proven knowledge extensively, now!

It would also end rubbish like ...

There were also technical issues for the Simonsens. The ventilation system broke down on a Friday night, and an engineer had to be called out to fix the problem. The technology in the Kettering house is similarly daunting with a plant room filled with pipes and tanks. Nik says if it goes wrong: “I have a number to call.”

What shall sound so dangerous describing a dramatic high-tech problem like The ventilation system broke down... can be no more than one ventilator that probably had no more power supplied and that similarly daunting with a plant room filled with pipes and tanks by implication just avoids the dirty chaos in British homes with pipes and pumps, tanks and meters dumped into dark and poky cupboards, an almost inaccessible attic or into so desperate needed bathroom or kitchen cabinets guaranteed avoiding proper access for maintenance or repair.

And cost? From experience it can be done for around £1,500 per square metre, Passive House Standard, turnkey - now, to compare like with like one should know what turnkey really comprises! And make sure that both products, turnkey homes, built to PH Standard, hence comparable in energy consumption! Plus, make sure that both homes are heated to the same levels, i.e. 21° in all rooms, but 19°C in the bedrooms. I know, complicated, but I said like with like! And efficiency does not come with throwing the dice!

Here is one pretty good wall... (not a PH wall) but a wall is just one element of the complex calculation, anyway.

Carpe diem!

* one litre of heating oil equates to 10.7kW, so your 150m² 5-bedroom house should not use more than the equivalent energy of 210 litres of heating oil per year or roughly £13 a month to keep a temperature of 21°C throughout the house (bedrooms 19°C). Now you compare!


Anonymous said...

As a Passivhaus certified bungalow, built by Hanse Haus up in Inverness, facing North (which made Solar gain interesting !)and it can be done, at the price, on time, perfect to such a high standard, strong, airtight PLUS being so, so comfortable, so warm, draft free, with 94.65£ of the heat recovered from the waste air to warmed up the fresh purified air. We are future proof and so happy.

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