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A typical appartment block in Hamburg, retrofitted to high energy standards

A typical appartment block in Hamburg, retrofitted to high energy standards

Germany is rightly famous for its wind and solar energy, but there’s an aspect of energy policy that is easily overlooked: energy conservation in buildings.

Dinah's old home, the brick building behind her.

Dinah’s old home, the brick building behind her.

While in Hamburg Dinah and I walked to the building where she grew up, a rather ordinary brick appartment block. Little seems to have changed; but the building is now far more energy efficient (and comfortable) than originally. First to go was the dirty and polluting coal furnace. Then came the more recent renovations: insulation, windows, balconies, and a more efficient system.

This building and its renovations is typical. The country has a large stock of old houses, appartment buildings, and commercial buildings that consume about 40% of the country’s energy, mostly for heating. Even if they have little historic value, it is neither realistic nor desirable to have them replaced by newer, energy efficient buildings. Instead, these old buildings – mostly post-war ones – are progressively being renovated into energy efficient ones.

Named EnEV, the initiative started in 2002 calls for energy audits triggered by major renovations, and requires energy efficiency updates such that no more than 70 kW-hr per square meter is required for heating and hot water. The EnEV intiative has a very ambitious target of renovating 3% of the building stock every year; this would translate into halving the energy consumption of the building sector.

A detail of the building, revealing the added insulation

A detail of the building, showing the added insulation; the older brick is below

The approach to insulating, in particular, is quite unique: where in Canada we would usually add insulation to the inside of a building, Germans more often will insulate the outside. Panels of rigid, light insulation with a brick facing called ETICS (External Thrmal Insulation Composite systems) are glued to an existing outside wall surface, a relatively quick operation that minimizes disruptions for the building’s occupants. These systems have now been shown to be very long lasting and have a low footprint even when considering the full life cycle which includes such factors as the energy embedded in their manufacture. In effect, a whole new industry has been created, which is thriving and is now looking beyond Germany at a growing export market, as the clip below shows:

The building on the right has been renovated, the left one not.

The building on the right has been renovated, the left one not.

These renovations don’t come cheap, of course; some homeowners are looking at a 20 year pay-off period, or even longer. “I’m doing this so that I won’t have to pay much for heat after I’m retired”, says one, “and I expect the kids will benefit once they inherit the house”. This sort of long-term planning is unheard-of in North America where people are quite mobile and energy improvements rarely affect the value of a home. In Germany, the law mandates stating what is the enrgy performance of any home or appartment for sale, in terms of energy units and energy costs at the current energy prices. There has been grumblings among tenants associations, though, who fear that renovations will make rents unaffordable. Rents are regulated and landlords can only increase the rent by no more than 11 percent of the costs; nonetheless, such increases can be hard to bear for people on fixed or small incomes.

But for all the growing pains of this initiative, kudos to Germany for being pioneers in this approach. They are solving problems that we haven’t even started considering in Canada.


Written by enviropaul

February 7, 2015 at 8:58 pm

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