Chiel Boonstra An Office Building Project Tax Office extension, Enschede Environmental design in practice

Tax Office Enschede “One of the first real cases of integrated passive design and active occupant control”

Energy Comfort 2000 European Thermie demonstration project Building as an energy system Integrated passive design + active control strategies Improved indoor environment Higher productivity

Key issues Tax Office Site location Flexibility Low primary energy use  Passive ventilation  Daylighting concept  Photovoltaic-cells Occupant control Sustainable materials / water systems

Site location Former railway-area Close to railway, regional and local bus station Close to enschede city centre Existing building retained through extension and renovation

Passive ventilation-concept Natural supply Via wind-pressure independent vents in facades Natural extraction Via chimneys on atrium Mechanical extraction Under extreme low wind conditions and high temperatures

Daylighting concept High daylight window Solar reflecting, light admitting glazingLightshelf Equal light distribution over office rooms Low vision window Clear glazing + light regulation + solar shading

Control strategiesManual: Windows, air supplyBoth: Night ventilation, lighting, heating, shadingAutomatic: Exhaust

EC 2000 monitoring programme Breakdown of energy flows Long term monitoring in typical rooms Short term monitoring, e.G. Airtightness Occupant questionnaire according to format european AUDIT study in 50 buildings

Conclusions monitoring High user satisfaction: reduced absence Daylighting and control appreciated Summer temperature requirements are met High reduction of electricity use Heating is 70% of total energy demand