The REWE Group operates stores throughout Germany and Austria. Energy and other resources are used to run these stores every day. The company is determined to systematically reduce the energy that these stores use and to design its buildings in a more sustainable manner.
Three areas of action were defined in the pillars Energy, Climate and the Environment of the group-wide sustainability strategy: Climate-relevant emissions, energy efficiency and conservation of resources. The REWE Group’s Green Building strategy is part of these three areas of action the REWE Group’s goal is to lower the amount of energy and resources used by its stores by applying the Green Building concept.
RG1: Green Building
“More sustainable products belong in more sustainable stores.” Based on this conviction, in 2008, the REWE Group began developing a new generation of supermarkets that make sustainability come alive for customers and employees and make a measurable contribution to sustainable development.
Modern, energy-efficient stores play a significant role in the measures to achieve the strategic objective of climate neutrality by 2040. In addition to the Green Buildings as important lighthouse projects, the focus is also on existing stores (for more information, refer to Climate Protection on a Company Level).
The Green Building concept of the REWE Group combines modern architecture with energy-efficient technologies and the use of renewable energies. For example, primary energy consumption was cut by up to 40 per cent compared with conventional stores. By successfully introducing the Green Building concept, the REWE Group has made the environmental and business case for building and operating more sustainable retail properties. Because the REWE Group frequently leases its stores, the support of investors and landlords for more sustainable building concepts must be gained. Criteria such as economic value, flexibility of use and commercial development costs are key arguments for this proven construction concept. Evidence of customers’ positive responses to this concept can be seen in above-average customer frequency and the related rise in sales revenue.
Next generation of Green Buildings
In May 2021, the first REWE pilot store with a new Green Building concept opened in Wiesbaden, Germany. The pilot store is not an ongoing development of the previous Green Buildings; rather, the decision was made to create a completely new design. At the start of 2016, the first ideas to create a new generation of REWE Green Buildings to succeed the existing concept were seeded. In summer 2016, this led to an architectural competition where REWE as the client remained anonymous to allow the architects the greatest possible freedom of thought. The result is the REWE Green Farming store in Wiesbaden: a pilot store and a prototype for the next generation of sustainable REWE supermarkets. A new, adaptable and sustainable modular store concept that can be customised to suit different locations and conditions in terms of design and construction. Although the store in Wiesbaden has a rooftop farm, the new concept does not envisage this for every new REWE Green Farming store. Rooftop farms will be included only at suitable, selected locations.
This urban farming area on the roof of the store includes a combination of basil growing and fish farming with a closed cycle. The fish dung is used to fertilise the plants, which are also supplied with rainwater. This reduces resource consumption and ensures healthy plant and fish farming. The farm supplies basil and fresh fish to a large number of stores in the region.
The stacked timber design of the roof and columns is an important building block in the use of sustainable material. The timber is completely visible and is not chemically treated. The design uses European coniferous timber from certified forestry inside and certified larch wood for the external supports that are subject to weathering. With its arch-like design, the innovative stacked timber support structure creates a very special atmosphere for shoppers. Since the individual elements are modular, future stores can be built much faster and easier than with conventional designs. The timber elements are also connected with bolts. At the end of the store’s life cycle, this will allow it to be demolished in such a way that the material can be reused – an important step towards a circular economy in the construction industry. In addition, with this concept, more timber is used in the building, which means that more CO2 is stored permanently.
The glass front and back facades of the store allow customers to see inside the store and employees to look out at their surroundings. Daylight is used optimally and is also introduced via a large atrium in the store. Large roof overhangs offer good protection against the sun. Outside the store, an innovative parking area layout minimises the paved area with no adverse effects on the parking spaces. The result is more than 1,000 square metres of permeable greenery that is planted with insect-friendly grass, bushes and numerous trees. For a holistic concept, the store focuses on regional and fresh produce.
For its pilot store in Wiesbaden-Erbenheim, the REWE Group is hoping to be awarded the platinum certificate from the German Sustainable Building Council (DGNB) (see also Certification by the German Sustainable Building Council).
The pilot store is currently being analysed with regard to potential improvements. The findings will be used in a standard concept so that sample construction specifications will be available for a future roll-out throughout Germany at many different locations. Parallel to this, DGNB is developing a multiple certificate for the latest generation of green REWE stores so that they can be built efficiently and sustainably and also be certified. The REWE Green Farming store in Wiesbaden already achieves the economic targets that were set, which is why deriving an optimised “blueprint” will also be practically feasible from a financial aspect. In new buildings, the new concept will replace the previous Green Building concept.
In May 2022, at the German Retail Real Estate Congress, the store was named “Store of the Year 2022“ by the German Retail Federation (HDE).
The elements of the Green Building concept
The concept includes the following elements, which are applied in accordance with the needs of the business location:
- Daylight architecture: Ribbon windows on up to four sides of the building and additional dome roof lights facilitate the use of natural light, which is complemented by an energy-efficient LED lighting concept. The natural light tremendously enhances the quality of time that customers and employees spend in the store.
- Atrium: The large atrium, together with the glazed façades, ensures energy-efficient use of daylight.
- Rooftop farm: Aquaponics, a combination of aquaculture and hydroponics, in the rooftop farm creates very good conditions for the cultivation of basil. The fish dung is used as a fertiliser. This system enables food production without pesticides and 90 per cent less water consumption than conventional farming, as the water is used twice.
- Organic building materials: The characteristic structural frame of a Green Building is formed by wood, a renewable resource. This is also the case with the front façade and, in many cases, with the roof shell. Environmentally friendly and recyclable building materials are also used in other areas.
- Renewable energies: Green Building stores use 100 per cent certified green power, just like all other stores, warehouses and travel agencies of the REWE Group. Additional photovoltaic systems will be installed where practical.
- Heating: For heating purposes, no fossil fuels are required thanks to the use of heat pumps and the waste heat of refrigeration systems.
- Use of rain water: To clean floors, flush toilets and water outdoor areas, rain water is collected in containers.
- Refrigeration systems and units: CO2, a natural refrigerant, is used for normal and combined refrigeration and deep-freeze systems. Propane, another natural refrigerant, is used for plug-in freezers. Buffer-storage units are used to recover heat. Glass-door refrigerated display cases for meat and dairy products help to prevent losses of refrigerated air. The energy efficiency of refrigeration units is increased by using integrated LED lighting systems and energy-saving fans and by forgoing the use of glass heaters for glass panels on freezer units.
- Sociocultural factors: Green Building stores are largely barrier free. They are also equipped with restrooms for the physically disabled and with baby changing tables. Factors such as visual comfort, ambient air and bicycle parking places near the entrance are considered as well.
Certification by the German Sustainable Building Council
In 2013, the REWE Group decided to apply the Green Building concept to all new construction projects and all new leases in Germany as long as fundamental conditions permit its use. The REWE, PENNY and toom Baumarkt DIY stores sales lines have received multiple certifications at the “Gold”* level by the German Sustainable Building Council (DGNB). New buildings are designed in accordance with the Green Building concept or the council’s criteria for sustainable construction practices. By including the criteria in the construction specifications of the sales lines, these requirements also apply explicitly to the leased properties of the REWE Group. At the end of 2021, 315 buildings had been constructed according to the Green Building criteria and another 159 Green Buildings are currently in the building or planning phase.
The DGNB’s seal of quality evaluates a wide range of building features. These include environmental aspects, the stages of the construction process and sociocultural factors regarding well-being, including visual comfort, ambient air, bicycle parking places and customer restrooms. The multiple certification of the building specifications significantly simplifies the certification process because the entire concept has already been subjected to a thorough review. This is a key pre-condition for the fast, cost-efficient development of Green Building stores.