Within a pool concept for the Westphalian town of Lünen, the “Lippe Bad” was opened on September 09, 2011 after a period of construction of two years which has been built according to passive house standards as the first public indoor swimming pool in Germany. The principal and operating company is Stadtwerke Lünen mbH.
The location of the new building in the center at the river Lippe replaces two existing indoor swimming pools and has been design for 230,000 visitors per year. In addition to the utilization by clubs and private guests, in particular the swimming lessons of schools play an important part. An own bus stop directly in front of the building allows the safe access for pupils.
In addition to the construction of the new building part, the task was to rehabilitate a former district heating station from the sixties of the last century to meet passive house standards and to integrate it in the new pool building in a sustainable manner.
Five pools have a total water surface of approx. 830 m². This water surface is divided in a 25 m Vario pool with four lanes and a diving basin as well as a 25 m sports and swimming pool with five lanes. Furthermore, a lifting-bottom basin, a warm water and recreation basin as well as a toddlers’ basin with adjoining baby care room are available. Also areas with chairs which can be used for catering purposes are arranged beside a rest area at the recreation basin. Due to the different temperature zones of the pool areas, the latter are separated by glass wall partitions.
The ground floor accommodates the pool areas and the changing rooms, sanitary and equipment rooms; a spacious lobby area with protruding canopy is provided as entrée. The whole bath equipment and staff rooms are located in the basement floor.
A high-quality 300 mm thick façade, roof and base plate insulation as well as a wood/aluminium post and beam façade with 3fold glazing form the thermal hull, reduce heat losses and allow increased room moisture which in turn reduce evaporation. An highly efficient heat recovery system, water saving fittings, a wastewater treatment system and heat supply by a biogas operated CHP are the major components of the energy concept. The swimming pool water is treated according to the highly efficient ultra-filtration principle and “inline chlorination” which renders the storage of dangerous substances unnecessary.
In addition, a photovoltaic system with an output of more than 100 kW which has been installed at the roof generates the major part of the power demand for the energy saving lighting system which is controlled by the daylight.
In addition to energy efficiency and minimizing of operating costs, particular attention has been paid to the comfort of users by freedom from barriers, use of automatic doors and very good room acoustics to which beside the acoustically effective wall and ceiling areas also the inclined façade and roof areas contribute. Large-area façade openings in combination with skylights render optimum supply with daylight.
Supporting components such as external walls, ceilings and columns consist of reinforced concrete. Non-supporting walls have been built from water-resistant cement slabs and provided partly with a ceramic lining.
The sustained material selection is also reflected by the roof structure which consists of glue-laminated wood and acoustic ceiling members of wood with finished surfaces. This white varnish of all wood components as well as the design of the wall and floor areas with light colored surfaces and fresh colors contributes essentially to the reduction of the use of artificial light.
All operating and utilization conditions of the Lippe Bad are controlled by accompanying monitoring. In this way, experiences and the potential of improvements shall become transparent and applicable to comparable building projects.