The environmental medicine, which takes place at FNF, is only found in few other hospitals in Europe. For the first time the ecological principles will be the basis of the future extension of the hospital. This includes energy production, energy- saving measures, materials, air change, utilisation of daylight, waste disposal and treatment of the recreational areas. The patients of FNF need an extremely clean indoor climate without any kind of degassing. The buildings and the constructions have on one hand to fulfil these needs and on the other hand to minimise the consumption of energy. Materials collecting dust cannot be used, the use of metal must be minimised and open wood constructions have to be avoided. Mineral materials like glass, ceramics, tiles and plaster are suitable. The new building at the FNF will definitely contribute to the ecological debate in Germany and through the partners of the hospital in the whole world. The aim of this proposal is to improve the conditions for the users of the buildings by using innovative (natural) sources in order to minimise metal used in the living rooms. By improving the daylight conditions, the need of electricity in the living rooms is being reduced, and by implementing the transparent insulation on the outer wall, the feeling of comfort inside the house will rise. In parallel the energy consumption will be reduced. The innovative element will primarily be used in order to improve comfort, daylight conditions and indoor climate for the users of the buildings and secondarily to reduce energy consumption and CO2 emission. An ordinary design approach for a hospital building project would fulfil the present requirements to the building envelope, have full mechanical ventilation and in some cases mechanical cooling with control strategies aiming at very tight tolerances of indoor climate. In comparison to this situation, several innovative aspects of the present proposal focusing on occupant demand in stead of building demand can be emphasised. The selected design team is a joint collaboration of German and Danish architects and consulting engineers and one of the main ideas is to exchange national expertise between the consultants. This can be exemplified by the strong position of German consultants on building materials and the strong position on insulation, daylighting, and ventilation of Danish consultants. Windows and constructions will be insulated with ordinary thermal insulation or transparent insulation to a certain level based on an energy efficiency approach. Special attention will be given to windows, because a lot of heat is lost through glazing and frames in the windows. In this project the windows are treated as multi-functional building components with respect to all the different parameters influencing the indoor climate and energy consumption and double skin facades will be introduced as well. A step towards a satisfying indoor air quality is a careful selection of building materials exposed to the indoor environment. Double skin facades with integrated natural ventilation and passive cooling Double skin facades are planned to be built into the glass facades facing east and west. By using these elements the innovative energy is integrated in an intelligent architectural way. The system is created in such a way that the qualities of the glass are used differently according to time of the year and the weather. During summer the glass can reject the radiation heat of the sun and by using a system of lamellas exclude the heat of the sun. During winter the system is closed and thereby keeps the hot air inside the buildings. By implementing the double skin facades the daylight conditions are improved and the use of electricity is reduced. The implementation of double skin facades gives a noise reduction from the mechanical ventilation and thereby increases the well being of the patients. Transparent insulation is planned on the facades facing south or west in order to improve the physiological conditions of the building and thereby the comfort for the patient regarding daylight and heating. Natural ventilation and passive cooling are sustainable, energy efficient and clean technologies and can improve the indoor climate provided good control strategies and components. The innovative efforts in the present proposal will focus on implementation of control strategies and components based on the findings of the detailed building simulation. The ventilation principle is hybrid with fan assistance in extracts from bathrooms. The inlet air will be preheated via a ribbed heat pipe system with low-pressure positioned in the facade and this element will be developed as part of the project. A roofed glass room is planned as a common entry between two patient areas. As a combined shielding of the sun and an innovative energy element PV integrated in the glass is planned. The system will be grid connected and sized according to the need of electricity of the glass-covered room and according to the architecture. The shielding of the sun increases the comfort and produces electricity at the same time. In order to complete the energy concept a CHP plant is included, in connection with a boiler for natural gas. In order to get the highest performance of the CHP plant and thereby the best economic solution the CHP plant is supposed have a running hours of approximately 5 500h per year. From the energy concept it is realised that the CHP plant is the most economic energy source for the FNF. The annual energy demand for heating (space heating, heating of ventilation air and domestic hot water) are reduced 41% for the demonstration project compared to a new build reference project. This reduction is due to an increased insulation level, transparent insulation and passive solar utilisation. The heat demand for ventilation is increased by use of natural ventilation without heat recovery, but this is compensated by a large reduction in electricity consumption for fans. The annual electricity demand (artificial lighting, fans and equipment) is reduced by 57% compared to a new build reference project. This reduction is due to the hybrid ventilation system, the utilisation of daylight and the use of energy efficient lighting installations with dimming. For the total energy demand an expected reduction of 46% (534 MWh) will be achieved in this project. Copyright 2005 All rights reserved. Supported by the European Commission.