Well, the experts haven’t yet agreed on how to call these new homes.
You might have seen them announced as Zero Net Energy Building (ZNEB) or Net-Zero Energy Building (NZEB).Basically it is the same thing. Well not basically.
These are homes that hardly consume any non-renewable energy.
Conventional Spanish homes (especially if they were built before the 1980’s) are not prepared to withstand the high summer temperatures and in winter are freezing cold.
However these new forthcoming houses which we could call them smart homes, are designed not only to adapt themselves during the different seasons but also to adapt to the nocturnal and diurnal times.
How? Well, accumulating heat when the temperature rises above the comfort zone, storing it to be used later when it is required.
However the fundamental plus of these homes is the fact that they require very, very little energy to maintain the users within the comfort zone by using very little non-renewable energy.
Although these new houses seem futuristic now, their standard will prevail by law in just four years.
The 20/20/20 rule
The EU demands that by 2020 the 20/20/20 concept shall be legislated by all the EC countries and that include Spain of course.
They want a reduction of 20% in energy consumption in buildings, minimizing the emissions of CO2 by 20% and increasing renewable energy to contribute up to 20% of all used energy.
This proposal has forced major changes in the sector of the construction industry. In fact, consumption of buildings accounts for 20% of total energy, almost as much as the industrial sector, according to the IDAE.
The guilty party: The European Directive 2010/31
The European Directive 2010/31 states that by 2020 all new buildings have to be zero energy consumption, i.e. all buildings must be so constructed that do not require any energy input or, if needed, must come from renewable sources. A goal that must be achievable by 2018 in the case of public buildings.
To be able to achieve this objective we architects must design buildings taking into consideration the orientation not just to obtain the best views but also taking into consideration the impact that orientation will have in energy consumption. Obviously there must be a careful selection of materials and construction systems that can meet all the energy needs of a passive building. However this is attained mostly by reducing heat or cooling consumption between 80% and 90% compared to a conventional house.
The truth is that there are no official guidelines in Spain so far, as to how this standard is to be accomplished. This is due to the fact that each EU country must regulate its own framework and Spain has not done it yet (as usual).
Better in the North
During these last years, different quality certificates, from mostly European agencies have emerged. There is only one example of finished housing which has used this criteria and it is situated in the Basque Country in Erripagaña, and another one, currently under construction, in Lezkairu in Pamplona.
Already built homes also can be rehabilitated following these parameters by improving wall insulation and sealing window openings.
In Germany, Switzerland, Austria and the Scandinavian countries there are thousands of passive houses that have the Passivhaus certificate, while in this country there are barely a dozen of these houses which have been certified. These passive houses have a lower demand for heating and cooling which mounts up to 15 kWh per m2, compared to 100 kwh in conventional housing, which translates into significant savings in electricity and gas bills.
A block block of flats in Lezkairu, designed by the architect Germán Velazquez, has chosen this demanding German standard for certification. In fact, it will be the first block of flats in Spain to be certified by the Passive House Institute in Spain, and the houses will be NZEB.
It is a very high standard of energy efficiency. The idea originated from a private German institute and they certify that a house which is awarded this certificate can actually save up to 80% energy.