Vertical visions.

Informed by climate and energy use, Ken Yeang's latest series of bioclimatic skyscrapers show how these concerns can be reconciled with a testing commercial brief.

Since the completion of Ken Yeang's Aga Khan Award-winning Menara Mesiniaga (AR November 1995) -- a cylindrical landmark building that has become an icon of Yeang's bioclimatic skyscraper series -- he has been engaged on a series of city centre towers in Kuala Lumpur and Penang, all nearing completion. Three of these projects, Menara Budaya and Central Plaza (37 and 27 storeys respectively, both shown here) in Kuala Lumpur's `Golden Triangle', and Menara UMNO (25 storeys) in central Pulau Pinang, form a set: each tower has almost identical programmatic characteristics but with varying site conditions and orientation.

The towers all incorporate a plinth of seven car parking floors with generous covered and naturally ventilated entrance courts, together with retail facilites such as banking halls and restaurants at ground level. Above the parking floors, the lettable office spaces all incorporate perimeter columns to yield the maximum free floor plate area. Each tower also has some communal uses at roof level, such as a terrace garden or swimming pool, and all incorporate some form of vertical atrium or sky court.

Menara Mesiniaga is set in a business park close to the airport and was customised for the exclusive occupation of IBM's Malaysian agency. In contrast, the towers of Budaya, Central Plaza and UMNO are all for multi-lettable occupancy, and are realised on slim, restricted urban sites in high land-cost locations with exacting construction budgets. Essentially these towers represent the acid test both of Yeang's philosophy and his ability to deliver added value in a highly competitive marketplace.

The crucial factors that make of these office buildings a user-friendly experience are all functions of Yeang's bioclimatic agenda. Astute design decisions on orientation result in elements such as lift cores (usually naturally ventilated and daylit) acting as solar shields; plan shaping to reduce insolation; natural ventilation options for the office spaces related to `thin' plan forms (also a function of the site plan) and the incorporation of painted balconies and recesses together with eggcrate and louvre solar shading. Northern facades are fully glazed to permit strategic views, often to distant hills.

While the orientation, the variety of forms and structural innovations are generated largely by climatic concerns, each of these design elements is also related to the economical provision of floor plates. The principles of Yeang's bioclimatic agenda are laced with his concepts of vertical urbanism. As a set, these towers incorporate an increasingly sophisticated range of materials and detailing, including marble and laminated float glass, and display a range of whole-building colour types, from pink (Central Plaza) to white (Budaya).

Taken together, the three towers provide proof of Yeang's ability to develop a strict typology and deliver a marketable product. Perhaps equally significantly, the marketplace is gradually coming to recognise that his architecture offers much more than commercially acceptable development. Ken Yeang's studio has a slogan posted conspicuously on a wall: `Everything depends on execution, having a vision is no solution'. However, his bioclimatic agenda is also a vision, and it continues to supply a real solution to the problems of contemporary architecture.