The “Petroleum Tower” Prominent and contemporary in style, the proposed GNPC New Corporate edifice, affectionately nicked named, the “Petroleum Tower” proudly stands as a symbol of natural wealth, as a symbol of aspiration and strong promise of the people of Ghana. This tower of “layers” takes its inspiration from the layers of life which are traversed before the precious black gold is found. A silhouette of glass behind these layers of concrete slabs in natural state, represents a vial of the precious liquid. The choice of natural and fair faced concrete is in consonance with the natural layers of sediments where oil is discovered. These slabs actively play a strong role of shielding the glass from the elements especially from the strong sun rays of Accra. DESIGN OVERVIEW Two layers of Design define the concept of this project, A Podium, the Tower/Main Frame incasing a glass vial. The first of these, the Podium, acts as a natural concert base punctured triangularly to reveal the glazing of the assess points. The second is the Glass Tower; a “glass vial” emerging from layers slashed from an oblong of 40m by 60m over a height of 75m and seated on the Podium. Employing an inspired use of generous overhangs to prevent direct solar ingress into the internal spaces through operable glass windows allow fresh air exchanges on all sides of the building. THE ATRIUM In the center of the “glass vial” unfolds a Atrium, a space with semi- sheltered public areas capped by a transparent glass roof supported by an interplay of steel trusses which allows in natural lighting bringing alive the indoor spaces and natural ventilation to minimize the energy demands required for cooling the edifice. The Atrium appeals to the mind and the senses and gives a sensuous experience to visitor of the building putting them at the center of things while encouraging promenading and movement through space, enjoyment of nature and social life and providing a visual antidote to the oppressive interiors and the formless external spaces of today SUSTAINABILITY FEATURES — Target LEED Certification in Design; Construction, Operations and Maintenance certification (for both "as design" and "as build") — Between 30-40 % reduction in energy use (compared to common practice building in Accra) — Use of natural light and natural ventilation (mixed mode) to minimize energy demand — Sun pattern driven building orientation to minimize solar exposure and energy requirements for cooling — Automatic presence detectors/sensors and high efficiency lighting — Overhangs optimized to provide shading from intensive solar radiation, reducing energy requirements for cooling — Heat recovery through the centralized fresh air supply system — Potable water demand minimization though rain water harvesting and condensate recovery from cooling units. — Use of water harvested for toilet flashing and irrigation STRUCTURE The structural skeleton consist of: 8m square grid of reinforced concrete columns plus an interconnecting slab system, reinforced concrete walled lift shafts and stairs to aid the columns and to resist lateral earthquake and wind loadings. Overhanging the outer columns are slabs of up to 6m length, and in decreasing dimensions to 1.5m. The overhang portion is to be an overhang for shading the glazed walls and windows. Structured fins along the main column grid lines are to be provided at the inner facing of the cladding glazing, to produce a vierendeel effect to aid in the cantilever resistance.
