Under the federally funded research project "Individual Mass Production of Intelligent Houses", the architectural office Maier, Stutensee has developed a concept with various partners in the years 2000 to 2002, which combines the advantages of the mass production of buildings, while taking into account ecology and the economy of individual planning.

Based on this concept, we created a little more than 900 spots with living units and apartments between 2002 and 2012. All rooms have a controlled exhaust air system with individual ventilation openings in the window area. For energy reasons, all opening sashes of the windows were fitted with magnetic contacts. When you open a window, the individual room control switches the heating to the frost protection position

The residential buildings are so efficient that at that time the buildings were below the high level of the Energy Saving Ordinance (EnEV) and KfW40 or KfW70 funds could also be applied for in the years 2008/2009 and 2012/2013.

The energy cost can be reduced by up to 30-50% compared to conventional construction methods and designs. The following points are or were taken into account:

Reduction of heat consumption through:

- Compact design
- Structural measures such as 18 - 20 cm thick thermal insulation of the facades
- Reduction of thermal bridges (thermal insulation under the foundations, connection details)
- Sophisticated heating system with wall heating and intervention in user behavior (window contacts)
- Networked heating control with individual room controls
- Controlled exhaust system that minimizes ventilation losses

Efficient use of energy e.g through:

- Regenerative heating of the system in our residential building in Hagenschießstr. 1 and 3 in Pforzheim through the use of geothermal energy and heat pumps.
- District heating supply through combined heat and power generation in the properties Nancystr. 18, 20 and Tennesseeallee 14, Karlsruhe.
- Some buildings are equipped with photovoltaic systems.

The Studierendenwerk Karlsruhe operates four photovoltaic systems. Three of them are located in the residence hall Nancystrasse in Karlsruhe. One system is located on the roof of the cafeteria at Adenauerring in Karlsruhe, which was financed through students’ contribution fees.

The following is brief information about the systems:

The system, which went into operation in April 2005, was the largest private photovoltaic system in Karlsruhe at the time.
The residence hall uses the electricity generated by the system, which was installed in 2022.

We have installed a thermal solar system to generate thermal energy in the residence hall Adenauerring 7 in Karlsruhe. The heat generated is used directly by the residence hall, thus reducing the consumption of district heating and therefore also the costs.

District heating:

We use district heating in 60% of our student residences. That is 1.961 student rooms out of 2.662. Furthermore, we are planning new buildings, if feasible, with district heating and look into the possibility of converting the residential complexes not yet supplied with district heating.

Green electricity:

Since January 1st, 2022, we supply our student residences with green electricity.

Cogeneration units:

In 2021, we replaced the aging and outdated heating system in the residence halls Zähringerstr. 4 and Bernhardstr. 11/Rudolfstr. 20 in Karlsruhe. A new heating system with a gas-condensing boiler was installed in order to reduce future energy consumption. In addition, a combined heat and power plant, or CHP for short, was installed, which supplies the buildings with heat and electricity. From an energetic, financial and ecological point of view, the respective buildings should directly use the CHP generated electricity.
With the renovation of the heating systems, we also met the requirements given by the law EWärmeG of the state of Baden-Württemberg. The law stipulates that at least 15% renewable energy must be used when renovating a heating system. Electricity generated on site reduces the strain on the public power grid. At the same time, the Studierendenwerk becomes more independent of price developments on the electricity market regarding this student residence.
In the residence Zähringerstrasse 4, we can expect a CO² saving of approx. 1 ton/year over the calculated life of the system of ten years. In the property Bernhardstr. 11/Rudolfstr. 20, CO² savings of approx. 8.8 tons/year can be expected over the calculated life of the system of ten years.

Windows open, heating off

For energy reasons, we have been equipping the opening sashes of the windows with window contacts for years. The window frame has been installed with an invisible room temperature controller. When the window is open, the supply line is interrupted, which de-energizes the heating actuator (closed without current) so that the valve can be closed.
We have been using this system successfully for years (“windows open, heating off”) and thus saving energy. This system can be used for floor and wall heating systems as well as for conventional standard radiators.

Ventilation

In the residence rooms, there is predominantly a controlled exhaust air system with individual air intake openings in the window area. This enables a constant indoor air quality.

Consumption certificates in the form of energy certificates are available for all residences. The energy certificates provide information about the energy quality of buildings and are part of the Energy Saving Ordinance (EnEV), which came into force in October 2007.

The residences‘ average energy consumption was determined to be 97.85 kilowatt-hours per square meter per year.

For certain products used in the residences, we pursue a kind of "common parts strategy" as much as possible. For example, the furnishing of the rooms is almost identical in the various residences, despite different procurement periods. This facilitates the possible the provision of spare parts and an exchange of products within the various residence halls.

We also try to implement the same practice with the floor coverings, e.g. tiles and linoleum.

With this approach, we do not have to stock special spare parts, furniture parts or floor coverings for each dormitory, instead we store everything centrally and use it when needed. In this way, we reduce the material requirements for the respective products in the context of new buildings and renovations.

Flooring

The Studierendenwerk Karlsruhe has been using linoleum, a sustainable floor covering, in many of its residences for decades. More than 1,500 residences in Karlsruhe and Pforzheim have this floor covering.
According to the manufacturer, up to 98% of the ingredients are of natural or mineral origin. The production is CO²-neutral and therefore does not contribute to global warming.
The floor covering meets our high usage requirements and we have been contributing to climate protection for years through the selection of our floor coverings.

Lighting

As part of new buildings and renovations, we plan to install LED lighting in the residences. Independent of this, we will gradually retrofit the lighting with LEDs in our currently owned residences.

Bedding

We offer our tenants bed linen free of charge during their stay. International students in particular use this offer repeatedly. After the end of the rental period, the tenants can return the bed linen to us, which will then be washed by a dry cleaning company and then made available to the next tenant if requested.

When our tenants ask themselves which means of transport is the best way to get to their destination, there are a number of options available in our student residences or in the immediate vicinity. Some of our residences are very conveniently located to the respective universities, which are reachable by public transport or on foot. Of course, the cheap semester ticket also pays off here, which students can use so that they can leave their own car behind.

For students who do not have their own bike, the Studierendenwerk Karlsruhe has also entered into a cooperation agreement with kvv-nextbike, which guarantees students cheaper use of rental bikes. kvv-nextbike bicycles can be found in many of our residences some of which are parked right in front of the residence. This offers climate-friendly mobility. Of course, there are also parking spaces for your own bike in our properties. Almost all of our residences have covered bicycle parking spaces. In addition to bicycle sheds or bicycle cellars, there are also inexpensive bicycle boxes for individual storage of bicycles.

Bikes left behind by previous students are sorted out and initially stored. Students always leave behind bicycles in our residences. After an appropriate period of time, we been offer a bicycle auction, which we have held for years, where these found bicycles then go under the hammer. The bicycle auction usually takes place at the beginning of the semester in the area of the dining hall at Adenauerring and is always very popular, as many bargains can be found here!

Should you need to use a car, you can use car sharing. There are car-sharing stations at various residences.

Overall, we offer a number of options for climate-friendly mobility.

Our potential tenants can already find out about the respective distances from the residences to relevant places, such as the next bus stop, the KIT Campus South or the city center, on our homepage. Even when the contract is signed, they are often made aware of the well-developed pedestrian and bicycle-friendly road network in Karlsruhe and the relatively short distances, which the use of a car because of the climate friendly alternatives.

The staff at the Housing Department use service bicycles very regularly.

As a manager of 20 student residences in Karlsruhe and Pforzheim, our top priority is still being able to offer needs-based living spaces at socially acceptable rents. One of our aspects here is that tenants save as much energy as possible or avoid wasting it as much as possible.

With the information and notes listed below, we want to raise awareness of this topic. Among other things, adjusted behavior can keep rising rents within limits.

Care should be taken to:

- Switch off the interior lighting when leaving a room, kitchen or apartment.

- Defrost the freezer compartments of the refrigerators regularly. This not only extends their service life, but also reduces the energy required for cooling immensely. This is certainly easier to implement, especially in the cooler seasons.

- Place a suitable lid on the saucepan while cooking and use the stovetop that matches the size of the pot. In most cases, you can shorten the cooking process and use the residual heat to finish cooking.

- Use the baking attachment of the toaster for baking 1 – 2 rolls or buy them fresh at the baker.

- Do not preheat the oven. Many old recipes still state that the oven must be preheated. This is actually no longer necessary with the current quality of electric stoves.

- To “shock the air” in living and sanitary rooms - even in winter - i.e. to open the windows fully for a short time (approx. 10-15 minutes) instead of leaving the windows tilted open for a longer period of time. Of course, you should switch off the heating when airing.

- Completely close the window. The handle should be pointing all the way down.

- Do not cover the radiators with furniture or curtains, so that there is optimal circulation and rapid room heating.

- Completely switch off TVs, laptops and tablets; do not not put them in standby mode. When not in use, the energy consumption can be significantly reduced by switching it off completely, which is definitely worthwhile for many devices over a longer period of time. Even a charger connected to an outlet, to which no device is connected, still consumes electricity.

- Wash at a cooler temperature. Today's detergents are able to deliver very good washing results even at 30 degrees, so that washing programs at 60 or 90 degrees are often not necessary. If you can use a drying room, this form of drying would be preferable to using a dryer.

FLIP THE SWITCH!

On September 1st, 2022, Deutsches Studierendenwerk (DSW) started an energy saving campaign called "Flip the Switch". The aim is to motivate students, especially the tenants in the dormitories, to save energy.

With FLIP THE SWITCH, DSW has put together many good tips on how to save energy in everyday life.

You can read more on FLIP THE SWITCH .