Florian Waldner, Communication, armasuisse Real Estate

Mr. Mäder, anybody who exchanges conventional light bulbs for new LED lamps and replaces the old refrigerator with a modern A+ unit increases the energy efficiency in their own household in a simple manner. How does the DDPS make its properties more energy-efficient?

With a portfolio of over 7,000 buildings and facilities, this is a little more difficult. The DDPS makes considerable efforts in the area of building envelopes and building technology. In the case of new buildings and refurbishments, we check whether they should be executed according to strict standards such as Minergie-A or whether Eco should also be applied. The heating, air and cooling systems are designed to be as energy-efficient as possible and adapted to operation in an optimum manner.

A property consumes most of its energy during its usage phase. How can users contribute to economical energy consumption?

Yes, more than two-thirds of the total costs of a property are incurred during its usage over the years. In a building, the share of costs for the operating energy – in other words, for electricity and heat – are considerable, viewed over the life cycle. It is therefore all the more important that users make good use of the rooms and utilise them efficiently.

One of the most important potential factors for minimising the energy consumption during the operating time offers itself right at the beginning, when the requirements for the property are defined.

Influencing the energy efficiency when defining the requirements – how does that work?

The more detailed the users’ descriptions of their real estate needs, the better we can react to them to find the most energy-efficient property solution. Let’s take, for example, the climatic requirements of a warehouse with instruction materials. This type of room needs very little or even no heating at all. On the other hand, additional rooms – such as laundry rooms or cleaning rooms with storage-like requirements – are integrated in the same zone area but insulated and heated selectively. This reduces the long-term energy requirements, because fewer building installations are needed.

Are energy-efficient buildings more expensive than conventional buildings?

Building an intelligent and sustainable building always costs a bit more. However, the decisive factor is ultimately the costs that are incurred over the entire life cycle of a property. Heating and cooling a sustainable building costs considerably less than a traditional building, which is less well insulated. However, our properties are not refurbished blindly according to Minergie standards. A comprehensive energetic refurbishment only makes sense if use of a building is continued in the long term.

The term sustainability is on everyone’s lips. Are energy-efficient buildings automatically sustainable and resource-friendly?

No, not automatically. The more the building is insulated, the more «grey energy» has to be expended to manufacture the building materials. The choice and quantity of these materials therefore plays a decisive role in conserving resources. On the one hand, a building should be as energy-efficient as possible in operation. On the other hand, we need to ensure that the energy accrued during construction – in other words, the «grey energy» – is kept as low as possible. We are therefore using resource-conserving building materials more often.

The DDPS buildings are producing more and more renewable energy, for example, using photovoltaic systems. At the same time, most refurbished buildings and new buildings comply with the Minergie standard, and therefore require comparatively little energy. Which additional successes have been achieved in the real estate portfolio?

In the real estate area, the VBS has been able to reduce greenhouse gas emissions by around 40% compared with 2001. The project «Energy Planning for Sites» was launched in 2010 to promote measures for increasing efficiency and reducing CO₂. In cooperation with external partners, armasuisse Real Estate is now examining and optimising over 50 sites all over Switzerland, which make up for 60% of the total energy consumption of the portfolio, as part of the project. Investments of over CHF 320 million in structural and technical measures have meant that the energy efficiency in these locations has increased by more than 10% and the CO₂ emissions have dropped by over 30%. The project will be expanded substantially over the next few years and is a key element in achieving the DDPS’s ambitious climate goals.