Location: Sydney, NSW
The site is located on the south-west corner of the CUB site, on the corner of Abercrombie and O’Connor Streets. The public domain plan for the CUB redevelopment creates new streets to the north and east, resulting in the Block 8 development being a new, free-standing building with frontages to markedly diverse orientations and urban contexts.
Of particular note is its eastern address across Carlton Street to the new Central Park, and its frontage to Abercrombie Street with exposure to afternoon sun and an intense traffic environment.
The CUB site is in the midst of a changing, rapidly emerging new precinct and place. To the north, a dense commercial mixed-use precinct is now being transformed by UTS into an exciting, inner-city education-based campus. To the immediate west and south lies historic Chippendale, a vibrant, inner-city suburb with a rich mix of traditional residential and light industrial buildings being adapted to new uses. It is presently isolated from the CUB site by the high Abercrombie Street traffic volumes.
Transition and integration with this inner-city fine grain to the south and west, as well as with the much denser and taller development to the immediate north is a key urban design consideration for the Central Park Block 8 site.
TCA have devised a conceptual design strategy that creates a distinctive architecture reconciled with the commercial brief targets and an interpretation of the building envelope constraints.
We felt that the envelope as currently described – an inherently boxy, squat form with a smaller box mounted axially on top – creates a kind of formalised, “wedding-cake” architecture as opposed to a more visually arresting and contemporary idea of slender forms arranged to gain access to natural light, air and permeability.
We therefore decided to interrogate the envelope; to understand the principles that informed it and if changes were to be considered then they would need to ensure that these principles remained intact. The primary intentions of the building envelope appear to be threefold:
– to build the edges of the building to the boundaries, that is to create street-defining built form,
– to ensure a defined level of solar access to existing development to the south and new parklands to the west,
– to provide a transition in the scale of built form, descending from higher and bulkier in the north towards the lower and more finely grained existing development to the south.
The latter two intentions are prescribed in the controls by solar access planes and façade setbacks. We therefore felt that if we constrained all new built form to within the solar planes and developed a reasoned architectural strategy for scale transition, we could make a good argument for variation to the envelope provided improved public domain and residential amenity outcomes could be demonstrated.
This approach has resulted in a quite different built form concept. Instead of a 7-storey “box” to the entire Abercrombie Street frontage with a secondary setback above, the design proposition is to split the building envelope east to west, into two distinct forms of 12 and 7/8 residential levels. This creates a vertical slot or chasm through the building, dramatically revealing the common circulation elements located centrally within the plan. Importantly, it also articulates the building form into two parallel elements that suggest both residential typology and the possibility of public movement between the street and the new Park.
This passage within the building is a kind of hybrid, multi-valent space. It is essentially public and open 24/7 at ground level for building and retail access, but is also the organising spatial element at each level of the building. The primary core containing lifts, services and fire stairs is located in the taller northern form, with bridges at each of the lower six levels providing access to apartments in the lower southern form. Part of the roof of this lower piece is planned for residents communal open space and activities.
The building is cleaved to comply with the solar planes as they slice through its basic prismatic volume. This creates a sculptural expressiveness at the upper levels and is amplified by the weaving vertical surfaces of the passage cut through the building to the Park.
An expressive approach to surface and materiality will re-inforce the basic architectural parti of the building. The street facades are planar, taut metallic skins punctuated by a lively pattern of openings to windows and terraces. The passage is treated differently: it has more complex surfaces of solid and void, open to the sky but punctuated by bridges. Strong colour is proposed to accentuate its arterial, almost visceral function at the heart of the building.
We also felt that this building and site would be suited to an alternative approach to the customary handling of the built form to ground plane relationship – that it did not need to bond resolutely with the city floor at the boundary, but rather that its primary forms could float over the gently sloping terrain tracing the sites natural topography, thereby inviting public access into and through the site.
This strategy opens up vistas and creates a stronger sense of connection between Chippendale and the new Central Park. It is a welcoming gesture to the existing community to the west, instead of presenting the Abercrombie Street face of the building as a barrier.