Once a big concept becomes fashionable, it threatens to deteriorate quickly into a pure marketing symbol. “Sustainability“ is such a concept. There is hardly a company currently not talking up their sustainability. No wonder – language researchers have noted that sustainability has become the buzz word and environmental groups complain about “greenwashing“.

I would like to make it very clear: a shopping center is not a nature reserve. And a solar energy system screwed onto a roof does not come close to making a building sustainable.

The correct approach for architects and project developers I believe is more a basic one: How can I plan real estate, carry out the plans, operate it so that it will have the most possible positive effects on its environment for the long-term, and at the same time have minimal side effects.

Firstly, the decisive factor here is the project authors‘ conceptual and planning perspective. Those who want to create real estate with the largest margins in the shortest period generally are not interested in sustainable real estate development. And those who do not feel the need to show any reference projects, are often not sensitive to the consequences of such a short-term and usually short-sighted approach.

Things can be different. As European shopping center market leader, the ECE is in the public eye. Politicians and city governments are taking a look at our urban gallery structures before they make decisions for their own cities. Moreover, we remain onsite as leasing agent and manager and assume long-term responsibilities for our planned real estate projects.

In this way, the ECE was already using sustainable planning before the concept was even a concept. In 1970, we opened the Alstertal Shopping Center in Hamburg. Closely adhering to the Hamburg Senate‘s city planning goals, we chose a site directly in front of a major commuter rail station, slated to become the centre of a new city neighbourhood. Flexible column spacing enabled for a simpler reorganisation without major construction, as originally, furniture dealers opened stores in the basement but these were in time replaced by many other types of businesses as per customer requests. As leasing agent, we have won over strong local partners, some of whom are still loyal to the location today. In addition, we completed almost all renovations and expansions without having to use additional natural ground.

In the decades to follow, ECE‘s project developers, architects, engineers and center managers continually worked to further improve the sustainability of our shopping centers. The goals are an improved handling of building land, land recycling, high durability and universal usability for buildings, unproblematic alterations or demolition if necessary, use of environmental, safe building materials and products, comprehensive materials management, energy conservation and minimising the land use criteria.

These procedures are not spectacular - but they are having an effect in their details. Just the use of the most recent type of energy-efficient light bulbs saves about 20 percent on energy. In times when energy prices are significantly increasing, these issues are more and more an economic concern. For this reason the ECE systematically informs tenants about technical possibilities and has started a cooperative program with Philips called “cool down“.

Of course, we are also asking ourselves how their shopping centers can be directly supplied with renewable resources. For example, for the Rhein Galerie in Ludwigshafen we examined all current available alternatives. Here it became clear that fuel cells are not currently suitable for shopping centers as these need large quantities of warm water and have high energy consumption throughout the day. Other technologies like geothermal energy have had many questionable and often illegal side effects at many locations, such as the heating of ground water. However, we have increased our fundamental research in cooperation with different universities to develop new approaches and to test their feasibility and their real impact on the environment.

Parallel to this we continue to look for improvements through innovative detail solutions. An example of these efforts can be found at the Ernst-August Galerie in Hanover:

• An intelligent control system enables natural aeration and exhaust via the roofs. Mechanical cooling is no longer necessary as positive pressure in the stores has been reduced and the stored night-time coolness is now sufficient to create a pleasant temperature. In this way 162,000 kWh energy consumption has been saved on air-conditioning, which corresponds to 35 tons of CO₂.
• To satisfy both the requirements of modern design and sustainable energy usage, ECE has asked that new LEDs for façade lighting be developed.
• As an escalator uses relatively a lot of energy, a new control system has been designed for intermittent operation. This essentially makes the escalators traffic-dependent. With high customer traffic, the escalators are fully operational. If the flow of customers decreases, the escalators slow down and speed up again when a customer steps onto the system. Only with very low customer traffic do the escalators go into standby mode.
• Additionally a 250 kilowatt photovoltaic plant has been integrated into the Ernst- August Galerie‘s roof system which saves 50 tons of CO₂ annually.

For us, sustainability also means using our own resources to get other people involved. For example, environmental groups operate information booths in the centers‘ mall and introduce the public to energy-efficient products. The fight against global warming must not be allowed to stop at the shopping center‘s exit.

by Jens-Ulrich Maier

Some concrete examples

Architecture

Tinted glass reduces the need for cooling

Shopping centers are only heated a few days a year. Unlike many buildings, which rely on optimising insulation to save on energy costs, here the smallest possible heat input is the decisive costsaving method:

• Solar control glass reduces air-conditioning needs and provides the necessary light intensity in the stores.
• Extensive "green roofs" create valuable biotopes in the city, balance swings in temperature and contribute to energy cost savings.
• Energy-efficient motors with low SFP values (specific-fanpower) handle the center's ventilation. Generously large heat exchangers with a reclamation index of 70 percent help reduce heating and air-conditioning needs.
• The rooms for cast resin transformers are primarily in the outer walls to avoid the necessity of a separate mechanical cooling process.
• Strict standards apply to insulation used in vehicle-accessible roofs. Foam glass is used for this purpose, also called cellular glass. Mostly recycled glass is ground up, heated, mixed with carbon and expanded.
• Use of durable German products (Jura marble, regional sand stone, native lumber) reduces transportation needs. And unlike the case when using materials from China, South America or Egypt, we can be sure that the native supplying quarries are restored.

It is especially important that shopping centers be able to adapt to the continually changing customer needs and retail trends without having to carry out major construction:

• By using static construction systems (no pre-stressed construction, no continuous beams) with sufficient load reserves, retail areas can usually be flexibly divided and converted.
• For the same reason, reserve space is planned into building technical systems for eventual changes in usage. The power supply system for the leased areas is equipped with electrical lines with variable connected loads.

Site selection

• Urban city sites reduce traffic as increasingly more customers travel to them with pubic transport, on foot or by bicycle.
• Furthermore, urban sites are an expansion of existing developed structures and can serve to strengthen them.
• Compact, developed sites reduce the necessary sealed natural ground; a shopping center's use of space is thus much better than that of a normal department store, as many functions (personnel rooms, restrooms, elevators) can take advantage of a shopping center's inherent synergy.
• Most sites do not undergo new construction but are rather converted. For this reason no new ground is sealed. Comprehensive construction and ground water experts assure that no significant ground water lowering will occur which can sometimes require major soil restoration.

Realisation

Smart lighting designs save electricity

• For every construction site, detailed equipment plans and logistics concepts are developed to create optimal operations on the construction site. Supply and clean up of construction sites are handled via rail or water transportation whenever possible. It is also determined if a stationary concrete mixing facility can help to reduce traffic around the site.
• Special construction debris collection bins assure that waste and trash is already sorted during construction.
• Reusable system formworks help to save on resources.
• The use of sound-absorbing enclosures for construction equipment protects construction site neighbours as well as workers from noise exposure.

Operation

Intelligent escalator management systems save energy

• With the help of modern, computer supported control panels (DDC system, direct digital control) heating, air-conditioning and ventilation are continually monitored and dynamically adjusted to actual needs.
• Energy-saving lighting, motion detectors and changing light levels throughout the day save on electricity.
• The center's air-conditioning is turned off 30 minutes before closing time to reduce energy consumption.
• The center's air-conditioning is turned off 30 minutes before closing time to reduce energy consumption.
• By comparing operating costs of all ECE managed centers, higher-than-average usage is identified and corrected.
• District heat supply and green electricity reduce CO₂ emissions. Conservative estimates indicate that the conversion of most of DES shopping centers to green electricity has alone cut back CO₂ emissions by 10,000 tons annually, the equivalent of 450 2-person households.
• The centers' waste is sorted.
• Cleaning contracts stipulate that environmental products must be used.