Queen of the Curve

Queen of the Curve

The dramatically curved facade and doublevolume entrance facing the intersection of Bancor and Amarand Avenue places emphasis on the pedestrian arrival experience.

The latest addition to Menlyn Maine – a mixeduse precinct in Waterkloof Glen in Pretoria’s eastern suburbs is Park Lane West. Menlyn Maine combines office, residential, retail and entertainment in a Green Living Precinct, with a distinctive character through its emphasis on innovative architecture and urban design. The development supports pedestrian connectivity in an effort to stimulate walking within the precinct, thus promoting a healthier, greener lifestyle.

This seven-storey building, primarily intended as office space, faces onto a prominent traffic circle on one of the main pedestrian routes through the precinct. It will, however, incorporate a groundfloor restaurant and co-working space in addition to offices. Its five-floor basement houses 630 parking spaces.

Given its prominent position, a certain architectural presence was necessary. The shape of the plot – and the fact that buildings in Menlyn Maine are built to the boundary line – prompted the curved glass façade, which serves as the building’s most eye-catching feature and imparts its main identity. It also provides a visual prompt to the building’s pedestrian entrance on the intersection of Bancor and Amarand Avenue.

LEAF Structures won the association of steel tube and pipe manufacturers (ASTPM) tubular category at the 2020 Saisc awards for the atrium skylight at Park Lane West, Menlyn Main.

Leaf Structures was briefed with creating a modern skylight with lightweight steel members and a clean geometry that would bring the right balance of heat and light into the atrium below.

The structural frame comprises 11 duo-pitched, three-pin beams made of rectangular hollow sections and two duo-pitched gable ends with stub columns. A thrusting three-pin beam design was selected to minimise the size of the steel beams, while not transferring a bending moment to the concrete supports. A combination of round and rectangular tubes was used for  ongitudinal lateral bracing. Hollow sections enabled the effective use of concealed pinned and bolted moment connections, resulting in a neat structure with minimal site welding. 

In addition to the clean lines of the structural frame, one of the skylight’s most eye-catching features is its distinctive 2.2m wide by 3.3m long point-supported glass panels. Each panel weighs approximately 350kg and is made up of two 10mm thick fully tempered glass lites laminated together. The elimination of redundant structures (often aluminium frames) on the cladding system, by using a point-support system and glass-to-glass joints, resulted in a highly transparent skylight. The total skylight clad area (glass surface) is 465m2 and of that only 12m2 is obstructed by support attachments (rotules) and silicone joints. The reduction of visual obstructions on the cladding element resulted in a skylight with more than 97% transparency. The high yield strength of the S355 tubes made it possible for small beams to be used, while the hollow sections produced neat, hidden connection details, making the structure aesthetically appealing. In addition, due to the stringent deflection requirements of the glass, both during installation and over the long term, the high stiffness of the structure meant the joints between each glass panel could be sealed with just a strip of silicone. No mullions were required, resulting in a skylight that provides exceptional and optimal passage of light into the atrium below.