Module B1 Study Book - the Graduate School of the Environment

Energy Consumption Figures:
• Actual total annual energy consumption was 60% higher than
expected. With an overall figure of 144kWh/m2 in 1998 falling to
135kWh/m2 in 1999, compared with target of 83 kWh/m2.
In 1999, electricity: 48 kWh/m2 (target 36 kWh/m2)
gas: 87 kWh/m2 (target 47 kWh/m2)
• High office electricity load is largely due to a high-performance
computer suite in the ground floor, operating continuously.
• Main increase caused by space heating requirements, brought about
in part by building envelope integrity. Air leakage was measured as
being 60% greater than the target air leakage index of 7.5m3/hr per
m2 in the offices & almost twice the target value in the rest of the
building. This has lead to the commissioning of a full air leakage
audit with proposed remedial measures.
3.2 The Commerzbank Headquarters, Frankfurt, Germany
Architects: Foster and Partners, London
• World’s first ecological tower: challenges conventional sealed box; 60
stories high
• Winter gardens spiral up the tower to be visual focus for four-storey
clusters of offices, linked to a central atrium, running full-height
through building and acting as a ventilation chimney
• Triangular plan: lifts and stairs located at corners to free up the core;
16.5m floor slabs
• Brings outside into the plan; maximizing daylighting; provides views
across city
• External temp reaches 35 degrees C. Aim to naturally ventilate for
65% of year
Lecture: Intelligent buildings, offices 79