by Lidija Grozdanić
|Villa Vals, an underground dwelling in Switzerland. Photo copyright SeArch.|
First, there was LEED
The world construction industry accounts for approximately one tenth of the Global Economy. It’s one of the major factors that affect our planet’s climate. In order to minimise negative environmental impact of buildings, the U.S. Green Building Council has developed the famous Leadership in Energy and Environmental Design (LEED) system. Introduced in 1998, its purpose was to identify and measure levels of sustainability in architectural design, construction and operation of buildings. Since then, developers have entered the global race for green epaulettes. Solar panels, wind turbines and rainwater harvesting are but a few of the sustainable mechanisms used in designing contemporary architecture. These “add-ons” have evolved into a kind of prosthetics for buildings - an expensive life support system that can make the most lavish houses green. Well, almost green.
But is it green enough?
The LEED rating system is based on points, certifying buildings that meet the prescribed standards for the appropriate category. This has recently caused a shift in focus from environmental benefits to gathering points. Many developers have started exploiting the rigidity of LEED requirements. Of all the mechanisms that get the building LEED certified, builders often deploy ones that are less beneficial but carry the same number of points as the more sustainable ones. Over time, LEED has become widely criticised for certifying buildings that aren’t actually green.
Look at it this way: the Passive House concept is LEED’s less flashy, but more diligent sibling. It has found its use quietly, proving every step of the way that it has serious potential for systemic application. The word “Passive” stands for a type of building that prevents energy loss by using natural resources. Rather than requiring high-tech materials or fancy energy-monitoring systems, it follows a few simple principles. It aims to minimise the use of energy systems in a home by using heavily insulated walls and an airtight building envelope. Not only that, it utilises passive solar gains (heat acquired by positioning the windows and glass surfaces in an optimal way). By using Heat Recovery Ventilators, the building acquires a healthier air quality and consistent indoor temperatures. Passive House construction cuts over all energy up to 70% while LEED projects usually provide increased efficiencies up to 30%.
While LEED system does not consider regional differences and applies the same rules to different climates, the Passive House is more flexible.
Winning the 1st Passive House Architecture Award in 2010, Bern-based Halle 58 Architects have designed their multi-family house in Liebefeld, Switzerland by following the principles of passive sustainability. The Gebhartstrasse Apartment Building was constructed using wood. Gravel was added under the floors as a kind of insulation mass, excessive heat is prevented using adjustable wooden shutters. About 76% of hot water supply is acquired by using thermal solar energy.
|The Gebhartstrasse apartment building. Photo copyright Halle 58 Architects.|
While LEED system does not consider regional differences and applies the same rules to different climates, the Passive House is more flexible. Designed by the architects of SeArch and Christian Müller, Villa Vals in Switzerland was built underground. The architects were able to almost completely eliminate the need for additional heating or cooling.
In Spain, students of the Institute for advanced Architecture of Catalonia (IAAC) have designed and built the Solar Fab Lab House. Its rounded shape was positioned for suitable solar tracking and for maximum living space with minimal exterior surface, in accordance to local climate conditions.
|The Solar Fab Lab house. Photo by Andrià Goula.|
These diverse approaches to sustainable building confirm the environmental superiority of passive houses. They teach us that sustainability can be achieved by using resources already present in our environment. Depending on the climate, passive houses can use solar and wind energy or make the most of earth’s insulation properties. In addition, people can chose a specific design for their homes, without having to make compromises.