Chiel Boonstra

An Office Building ProjectTax Office extension, Enschede

Environmental design in practice

Tax Office Enschede

““One of the first real cases of One of the first real cases of

integrated passive design andintegrated passive design and

active occupant control”active occupant control”

Energy Comfort 2000

European Thermie demonstration project

Building as an energy systemIntegrated passive design + active control strategiesImproved indoor environmentHigher productivity

Key issues Tax Office

Site locationSite locationFlexibilityLow primary energy use

Passive ventilationPassive ventilation Daylighting conceptDaylighting concept Photovoltaic-cells

Occupant controlOccupant controlSustainable materials / water systems

Site location

Former railway-areaClose to railway, regional and local bus stationClose to enschede city centre

Existing building retained through extension and renovation

Passive ventilation-concept

Natural supplyNatural supplyVia wind-pressure independent vents in facades

Natural extractionNatural extractionVia chimneys on atrium

Mechanical extractionMechanical extractionUnder extreme low wind conditions and high temperatures

Daylighting concept

High daylight windowHigh daylight windowSolar reflecting, light admitting glazing

LightshelfLightshelfEqual light distribution over office rooms

Low vision windowLow vision windowClear glazing + light regulation + solar shading

Control strategies

Manual:Manual:Windows, air supply

Both:Both:Night ventilation, lighting, heating, shading

Automatic:Automatic:Exhaust

EC 2000 monitoring programme

Breakdown of energy flowsLong term monitoring in typical roomsShort term monitoring, e.G. Airtightness

Occupant questionnaire according to format european AUDIT study in 50 buildings

Conclusions monitoring

High user satisfaction: reduced absenceDaylighting and control appreciatedSummer temperature requirements are met

High reduction of electricity useHeating is 70% of total energy demand