CH2 targets and maximises the penetration of natural light within the building, reducing the requirement for artificial lighting.
The building’s north and south facades are comprised of alternate vertical bands of glass and thick concrete walls containing supply-air ducts (on the south side) and exhaust-air shafts (on the north side). The shafts widen towards the upper levels in order to facilitate air supply and exhaust.
Conversely, the windows are at their widest at street level, narrowing at the upper levels. This enables more light to be admitted to the lower levels of the building, where light access is restricted by surrounding buildings and there is less air demand at the end on the air ducts.
CH2 takes advantage of natural light by:
- locating windows at the highest point of the curved concrete ceilings
- an external ‘light shelf’ on the northern windows that, while protecting the windows from the direct rays of the sun, also bounces natural light into the building
- moveable timber shutters that remain open to catch the morning sun, closing when the sun is in the western sky in the afternoon
- careful positioning and use of blinds to the northern windows. These windows are divided into upper and lower sections, each with its own blind. The upper blinds are only needed when the sun is low in the sky in winter. The lower blind is a partial blind (900mm high), to protect from the direct rays of the sun, while still letting in natural light.