Healthy building: an energy efficient air conditioned office with good indoor air quality.

The NORWEB Headquarters in Manchester, UK, is an air conditioned energy efficient office building of unusual design, completed in 1988. It has three stories with overhanging canopies providing solar shading and 21 % solar control glazing. The open plan interior is ventilated by a displacement system with three twist outlets in the floor to each desk position. A detailed questionnaire survey showed this to be one of the 'healthiest' buildings tested so far, with a very low 'building sickness symptom score'. Air temperature, humidity, air speed, fresh air, noise, dust and lighting were monitored and found to lie within accepted guidelines. Fine dust levels were lower than outside. Energy costs monitored over three years proved to be low for a building of this type. The achievement of good indoor air quality combined with energy efficiency is attributed to good passive design features, the displacement ventilation system, a limited smoking policy and active participation of the end user at all stages of the design, construction and management of the building.