The projects architectural expression is primarily one of a sculptural rooftop addition that has been precisely driven by the project’s technical and spatial requirements as well as the aspiration to reclaim the original 15 metre curtilage which originally framed the building. The proposed rooftop structure seeks to reconcile the disparate requirements noted above by providing a solution that addresses the envelope and technical demands of the future trigeneration facility, whilst providing an outcome that supports and responds positively to the future site conditions, heritage requirements and importantly, aspirations for project’s identity in the context of the GreenSquare Town Centre. The rooftop addition has been conceived as an extension of the original building, a new layer of history much like those that can be read in the layers of brickwork that make up the existing facades. In this regard it is an object that grows from the building as opposed to one that simply rests upon it to promote itself.
The proposed sculptured roof-top crowning element is to be formed from bays of interlinked blades of varying depths spaced to meet open area requirements for ventilation. They will be finished in a weathered copper toned metallic finish to compliment the materiality of the original building. The structure uses the technical constraint of 80% free open area to create a screened enclosure that results in an optical visual play through its materiality and form, play of light and shadow, and ever-changing transparency (resulting from the varying blade depths as one circumnavigates the building). The enclosure has a lightness but at the same time a weightiness that compliments and responds to the solidity and mass of the original building. This visual play is further enhanced by a deceptive structural design solution that eliminates secondary sub-framing accentuating the optical play of solidity and lightness. The combination of these techniques allows it to take on an ethereal quality elevating it from a purely pragmatic and technically responsive building to one befitting of civic quality and pride.
The ‘up-scaling’ the overall building envelope as a consequence of the rooftop addition results in a scale shift that elevates it to a more appropriate scale relationship with that of the future surrounding buildings that will vary in height from 18 storeys to the north to 8 storeys to the south. At the same time, the scale and rectilinear form of the rooftop addition also respects the original building’s robust rectilinear geometry, and this is further enhanced by establishing a flush alignment between scalloped rooftop structure and the existing perimeter masonry walls. An expressed shadow gap articulates the junction between the new and the old, and doubles as a concealed perimeter box gutter.
Existing window openings are dealt with in varying ways as determined by either technical (acoustic) requirements, as well as aesthetic and overall compositional requirements. Proposed window treatments consist of either restored original windows, restored windows with new flush-set glazing located externally for acoustic performance requirements, entirely removed and replaced with new acoustic flush-set glazing as a contemporary insertion, or removed entirely and bricked-in with recycled bricks in a stack bond pattern and slight setback as a remnant marking of the original window opening. In some instances, window sills have been slightly lowered to act as viewing windows into the engine rooms of the trigeneration plant, which is response to one of the key project aspirations to become a showcase facility for the public to observe, engage and interact with. The proposed treatment of the exiting windows provides a modulation to the facade that results in a balanced reading of the buildings past use whilst acknowledging it’s current state as an adaptive re-use facility.