Office Khulisa

Like much of the current ventures of TWS Architects, Office building Khulisa, situated in Parktown North, strives to incorporate practical forms of passive design and those of earth conscious alternatives.

Khulisa possesses two essential functions of passive design; the first focuses on Orientation. Of the consideration of orientation, one will find therein three intermediary functions that specifically deal with natural light, cooling and heating. The building, designed rectangular, is situated with its length façade facing north. On this northern facade one metre “overhangs” are created by the balcony at first floor level and the roof which serve to screen the full-height windows of both floors. In addition adjustable screens are situated on this facade as devices to manipulate glare and sunlight. These forms of design work to direct sunlight penetration -- therefore mitigating heat in the summer; in the winter the screens can be moved to allow sunlight where required.

Carrying the same principle, the West and East façades of the building have been designed to accept direct sunlight in winter but screen it off in summer. These cleverly designed forms of practicality work with the rising and the setting of the sun which, in Johannesburg, rises South Easterly and sets south westerly in summer – thereby reflecting off the angled screens whilst the sun is still low enough to penetrate these faces of the building – and rises North Easterly/sets North Easterly in the winter thusly changing its angle to drag into the screens rather than being reflected.

The second essential function of passive design is one of compatibility and alternative concern. A portion of the roof is sloped towards the North and hence raised towards the South providing the opportunity for clerestory lighting on the south face. Panels of photovoltaic cells, angled because of the slant, will be directed north towards the sun for optimal efficiency. The southern clerestory windows can be ably opened in summer thereby providing escape for hot air and promoting natural circulation of air without any form of mechanics. The building is intentionally surrounded with strategic vegetation which will provide cooler air to the surroundings in summer.

Construction of the building should be underway in 2010 and the unique design of TWS architects actualised in its solidarity and form