My entry for 12 September. Picture & Story:
Wärmedämmverbundsystem, Energieeinsparverordnung, Passivhaus
A little German lesson today covering a new cultural phenomenon described in the words above.
So what is it all about?
Traditionally humans built houses that breathe, which means the walls let air and water in and out to a certain extent meaning there will never be too much water inside, because it can go through the walls to the outside and balance the concentration out.
Trouble is that this kind of house needs a lot of energy except you build very thick walls that insulate against heat and cold but this has gotten so expensive that most people do not do it and build thin walls.
To save energy, people had the idea to build houses that are air tight. The air and heat exchange will then be conducted through a passive or active air flow system. That means, that the hot air that is going out is heating the incoming cold air or vice a versa, depending on the time of year.
This way you save tremendous amounts of money and energy for heating and cooling both of which contribute about 1/3 to world energy consumption.
A lot of development in that technology has been done in Germany and so the German government tried to push the stuff into the market which is not a very bad idea but the way they did it means, it will in the end not save energy but waste it.
The reason for that is a technical one. The government says how much energy the house shall consume at maximum but they give no technical guidelines how to and how not to reach this kind of insulation values. So what most people do is basically to buy mountains of styrofoam and nail them directly to the walls. This might work in a new construction, a house that is from the beginning planned as air tight with a good air flow planning, active or passive.
But many companies do the same to houses that are 100 years old or 50 years old and were from the beginning constructed as air conducting, as breathing houses.
What happens then is, that the water can not get out of the house and in consequence the house gets mouldy and rots.
It is possible to insulate an old house correctly but it requires a lot of skill and precision and it is much more expensive.
Foam insulation is also a problem for the fire brigade. If you plan to insulate your house it's a good idea to not only consult an architect and someone who really knows how to manage the air flow in a construction but also the fire experts that will evaluate how your insulation will behave in case of a fire. The Kensington Torch in London, killing a lot of people should be a warning to all.
The planning and qualified execution of the plan will be very expensive compared to getting some cheapo-workers from Eastern Europe hammering styrofoam to your outer walls and cashing in on the state money.
Trouble is that the law doesn't make any distinction between the qualified and unqualified way to do it so Germany will see hundreds of thousands of houses rot and being torn down and mega tons of styrofoam having to be dumped in some way. I am looking forward to the time in roughly 10 years, 15 years 20 years when the consequences of what we do today will surface.
Now the little German lesson:
Wärmedämmverbundsystem
This is the insulating construction in its totality including the air flow planning and execution.
Energieeinsparverordnung
This is a law requiring you to save energy but not telling you in detail how to do it and how not to do it.
Passivhaus
This is a very clever idea to build a house from the beginning in the way that it saves energy in the climate it is being constructed and that it saves energy without any active airflow management, heating or cooling system. This is the most intelligent way to build a house, but it is also very expensive and only a few people know exactly how to do it. In general it is easier and cheaper to realise such a thing in huge constructions than in the small constructions.
About The Picture:
Brown is the nice house, roughly 100 years old
Ugly is the old cladding which alloweded the house to breathe giving the wooden constructon between the house and the cladding
Ugly & dangerous is the new cladding quite possible air tight & burnable....
