Construction World December 2016

C

Professional Services

90 RIVONIA ROAD: NEW OFFICES FOR WEBBER WENTZEL Sited on a prominent corner in the financial hub of Sandton, 90 Rivonia was procured through an RFP process in which the tenant wished to consolidate several disparate business units into a united campus to flexibly accommodate growth and engender collective pride.

The architecture expresses the major tenant’s positioning as an African law firm, concerned with transparency, equity, and humanity. The architects focued on the use of contemporary yet timeless design, internationally referential and locally grounded. The core concept creates a place responding to the site specifics, knitting the company into the supporting environment. It has seven floors of parking – four below and three above ground, balancing sensible urban design with commercial construction realities – fed by multiple accesses at different levels. The E-plan form places a strong spine against the eastern boundary, from which three north-facing fingers stretch out. The environmental focus was at the forefront of the design, construction, and operational phases of 90 Rivonia. The sustainable design approach with integrated technology realised a reduced carbon footprint, improved working space, and lowered operational costs. Full utilities backup ensures grid independence and business continuity. Sensor-driven light fittings and thermal storage HVAC flatten the peak load energy demands, and the conservation and re-use of water with water-efficient sanitary fittings reduces the potable water demand. Individual metering of utilities consumption for different zones allows monitoring and response to leaks and inefficient use. 90 Rivonia has a 4-star GBCSA rating. A number of design innovations are worthy of mention at 90 Rivonia. The commercial reality of accommodating a large number of parking bays in a city centre building often separates the street and the building with above ground parking. At 90 Rivonia, this was mitigated by stepping the parking floors back to create a tilted podium which steps down to the street edge to draw people in to the scheme. The design of the new building brought together various departments of the tenant who were previously housed in separate buildings, creating new opportunities for learning and working together, and casual exchange.

The façade design combined a number of approaches to glazing, the most innovative of which is the floor-to-ceiling naturally- ventilated double-façade with a 600 mm cavity between an external single glazed jumbo glass panel connected with stainless steel pushers to an internal performance double glazed SIGU. The cavity’s inherent shading prevents radiant heat and maximises daylighting without glare, and the naturally ventilated panels allow air in and out to cool the façade minimising the load on the HVAC system. Set inside the cavity, automated sun-responsive blinds address direct solar angles adjusting for the suns path and cloud cover, and override switches provide individual control for building occupants. The facade design comprises double facades around cavities, single facades, and mechanically fixed stone and tile panels. The technical and environmental advantages of the double façade system are discussed above, and a further advantage is that the entire façade is designed considering disassembly, improving sustainability and resource management. The use of these innovative designs and technologies has increased knowledge transfer amongst the construction teams and the asset and facilities management teams. The client’s clear show of confidence in the location in redeveloping 90 Rivonia has contributed to the growth of the Rivonia/Katherine precinct and the implementation of a City Council urban design framework for the area. The construction technology choices and building systems are being adopted in other contemporary developments demonstrating the impression the scheme has made in the community and the industry. The design choice to open the scheme to the street and create a large garden, rare in the CBD, has contributed to the positive perception of the development.

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Project information • Company entering: GLH Architects • Client: Redefine Properties • Start date: April 2013 • End date: December 2015 • Main contractor: Group Five Building • Architect: GLH Architects • Principal agent: SIP Project Managers • Quantity surveyor: Brian Heineberg and Associates • Consulting engineer: PURE Consulting

Construction WORLD

DECEMBER • 2016