Responsible Construction
Author: Michael Vogel
More than half the buildings that will exist in 2060 haven’t even been built yet. That’s precisely why sustainable construction is already necessary today. A few examples show that many things are feasible these days.
Bosco Verticale, “vertical forest”, is the name of two high-rise buildings in Milan. Their facades are covered by a carpet of plants measuring almost 2,300 square meters. They serve as a buffer against summer heat and winter cold – and thus reduce energy requirements. This has a positive effect not only on the 19 and 27 floors of the two buildings, but also on the urban micro-climate in the surrounding area. The additional water demand is covered by groundwater, the pumps are solar-powered.
When it comes to sustainable construction, most people immediately think of such spectacular buildings as the Bosco Verticale. But if you take a look in databases of relevant certification systems, you quickly discover that sustainable buildings usually don’t look spectacular at all. It’s their inner qualities that matter, as it were. The following examples from the recent past show that many things are now possible in sustainable construction.
Sustainable construction projects on all continents
The new building at the National University of Singapore for the “Design and Environment” faculty had to be sustainable on principle alone. After all, students there are studying all about the construction and living of tomorrow. The building has a widely overhanging roof, which, together with the east and west facades, protects the interior from the tropical sun. The air conditioning doesn’t cool as much as usual, but circulates the more humid air at a higher rate. The building is self-sufficient in energy due to a photovoltaic system.
Alfandre Architecture’s office building in the small town of New Paltz, New York State, meets passive house standards. According to the architecture firm, it was one of only 17 zero-energy buildings in the US when it was certified in 2019. The building collects rainwater and uses it as domestic water for the toilets. Solar panels supply the power. High-quality insulation was used in the walls and roof.
Nursing homes and social housing in passive houses
But it’s not just about office buildings. In the municipality of Camarzana de Tera in the Spanish province of Zamora, a nursing home was in need of an extension. It’s now considered the first nursing home in the southern European country to have been designed as a passive house. Better yet: The building generates more energy than it consumes. This is made possible by a passive cooling system in addition to the solar power and heat supply. And a greenhouse connected to the dining room alleviates the winter chill, facilitates ventilation in summer, and also serves as a vegetable garden for residents.
Even social housing can be retrofitted to passive house standards. This is what happened in the French municipality of Raon-l’Étape in the Grand Est region in the case of a multi-party building with 24 apartments. The facade was clad with prefabricated wooden elements and fitted with an energy-saving ventilation system. The required energy supply is provided by pellets made from local wood.
Even if there are commonalities in many projects on all continents, sustainable construction has many faces. Interestingly, more than half of the buildings that will exist in 2060 haven’t even been built yet. This was pointed out by Inger Andersen, Under-Secretary-General at the UN, in her speech at the COP26 climate conference in Glasgow. How we build today will therefore determine the real estate sector’s sustainability decades from now. This is probably one of the reasons why the Danish Andersen gave her audience a clear motto: “We have to build better.”
Three Questions for Mike Verhoeven, auditor for the German Sustainable Building Council (DGNB) and responsible for the Sustainable Building product group at DEKRA.
Mr. Verhoeven, what role does sustainability play among property developers, architects, and project developers these days?
Verhoeven: The topic still gets somewhat neglected but is becoming more important. Many people don’t really know what sustainability means in terms of a building’s construction or operation. There’s often a fear that the project could be too expensive. Then again, property operators like hotels often already act sustainably – they’re just not aware of it. Making a building attractive for users already contributes to sustainability. The sociocultural component is an important sustainability factor, but one that often goes unseen. It concerns external relations or indoor climate, for example. Energy efficiency, on the other hand, is on everyone’s mind when it comes to sustainability, although it’s only one aspect.
What are the benefits of sustainability certifications for real estate?
Verhoeven: They’re not just a marketing tool; if you take a closer look, certification means much more. For example, dismantling is already part of the plan in certified buildings. This produces less hazardous waste because individual components of different trades can easily be separated from one another. Some of the building materials can then be reused. This example illustrates very well that sustainable construction must be planned from the start.
Which is easier to build sustainably: a single-family home, a commercial property, or an urban neighborhood?
Verhoeven: A building is still a building. A single-family house may not be as elaborate as commercial property in terms of technology, but the approach itself is the same. It’s different with urban quarters. When it comes to energy supply, for example, consider integrating a local heating plant that heats all the buildings. But aspects such as traffic routes, micro-climate, greenery as percolation area, as well as the type of vegetation also play a role.