Sustainability is all about thinking ahead. The higher the commitment in the initial vision, , the greater the need for thought about how to incorporate the challenges posed by sustainable construction into the project. The generations to come will have their own needs and particular expectations which require thought outside the standards of today right at the outset of the project. The features which must be considered as part of a sustainable approach extend from energy efficiency, user comfort and landscaping to the choice of construction materials.
One of the aims of the Swiss Federal Council is a carbon-neutral Switzerland by 2050. On the other hand, construction project promoters must have a vision and an energy strategy for their projects here and now. The challenge is formidable: additional costs must be avoided while reducing the project’s carbon footprint at the same time. This is why right at the outset it is so important to study each aspect with all the parties involved – investors, architects, construction companies and staff – and to take decisions about the level of sustainability at the planning stage.
Excellent energy efficiency and costs under control
Adopting a sustainable approach has an impact on costs. However, some of these costs can be reduced by federal or cantonal subsidies. In Geneva, for instance, a law has been passed to overcome the reluctance of project promoters. The law waives supplementary property tax on buildings complying with high or very high energy efficiency standards (HPE Rénovation, HPE Neuf or THPE-2000W), i.e. stricter standards than the minimum required. This exemption lasts for the next 20 years. Without a doubt, buildings complying with THPE-2000W are intended to become the norm.
Setting the bar high often means avoiding solutions certain to be more economical in cost terms but which are less sustainable, such as reinforced concrete. The life cycle of this well-tried and often-used material actually consumes and generates a lot of grey energy, mainly due to the cement component. Early consideration of alternatives which consume less energy and emit less CO2 can prove to be worthwhile. In one of its projects at Winterthur, Implenia Suisse SA replaced a reinforced concrete structure by adopting a wooden framework for the building. The result: the company established that CO2 emissions were 20% lower than for a traditional reinforced concrete structure.
Sustainable real estate projects which are practical and comfortable
Every sustainable real estate project must provide its users with an attractive quality of life but also address the practical consequences which arise in meeting that objective.. A very urban environment close to a railway or under a flight path demands the construction of a building envelope with excellent overall performance in order to achieve low sound levels in the building. The builder has to seek the assistance of an acoustic specialist, particularly for the insulation between the housing units and the neighbourhood.
Visual comfort is just as important for office buildings as for housing. The building has to offer a level of well-being while meeting energy conservation targets. The project promoter will seek well-thought-out window designs to make best use of natural light and thus limit the need for artificial lighting. The buildings must therefore not be too deep: natural light must be able to penetrate the building in all seasons of the year.
At the present time, mobility is the least certain aspect of a construction project. Project promoters almost find themselves having to answer questions more akin to those of futurology. In future, shared car parks or “smart car parks” drawing on artificial intelligence and connected objects will perhaps be the norm. When it comes to equipment, it is necessary to leave a certain amount of “wriggle room” – between electromobility, which is certain to transform people’s habits, and the promising potential of hydrogen, anything may be possible.
In real estate, sustainability also equates to health
Just like concepts of acoustic and visual comfort, sustainable construction cannot ignore the health of its future users. Floor coverings, paints, adhesives and mastics contain chemical products which come into direct contact with the air. Thanks to updated legislation on construction products as well as certain European regulations, builders are becoming increasingly informed. As a result they will tend to select the least harmful materials. Laboratory work and quality controls applied in building approval processes remain necessary to check the absence of formaldehydes and solvents, volatile compounds which can impact our health adversely.
A further important dimension of a sustainable construction project is thermal comfort, especially in the face of climate change which is affecting us now and in heat waves to come. Modern insulation enables buildings to consume little energy and so this problem is related more to spring, summer and autumn. The goal is to maintain the temperature below 26°C in the interior throughout the year, whatever the weather. Thus simulations are indispensable for defining the cooling system and the ventilation model which is technically feasible and legally possible.
Exchanging ideas and the regeneration of biodiversity
Leaving plenty of space for living and nature is inseparable from the adoption of a sustainable approach. The landscaping of an eco-district or a building must promote social and intergenerational interaction. Public spaces must find an acceptable compromise between spaces for relaxation and recreation on the one hand and habitats for small members of the animal kingdom, for example rodents and amphibians, on the other hand.
In Green Village, Geneva’s model site for sustainable real estate, the selection of tree species and decorative plants is also pursuing this objective: it aims at integrating native and incoming species in order to promote biodiversity. This is in line with the One Planet Living (OPL) approach of Bioregional and WWF International.
Recycled materials and the circular economy
These areas conducive to biodiversity can, of course, include urban allotments and at some future date communal composting centres as a way of removing organic waste. The nutritional and educational virtues of locally grown food are well known. The energy-related benefits require a little more thought: they entail less transportation and processing. The same goes for construction materials originating in the locality and generating less grey energy.
Using their expertise, the project promoter can move towards the most recyclable options and perhaps the most recoverable ones to highlight sustainability and promote the circular economy. Although a real challenge in a globalised world, the sustainable approach is the way for the future, and its time is already here.
Discover how the Green Village is committed to sustainability
Located in the town of Grand-Saconnex, Green Village is the first real estate project in Geneva (and one of three pilot projects in Switzerland) to receive the One Planet Living® label. The sustainability action plan is based on ten principles, which requires a real commitment from WCC, Implenia and the city of Grand-Saconnex.
For this reason, each building in the Green Village will be named after one of the major international agreements on sustainable development.