Nedbank made their intention of achieving a 5-star green building clear during the procurement of the professional team, and appointed a dedicated sustainability consultant, accredited with the Green Building Council South Africa, to guide the team towards achieving this goal. WCE Consulting Engineers, a multi-disciplinary consulting firm based in Windhoek, Namibia, and Solid Green Consulting, a sustainability specialist firm based in Johannesburg, South Africa, formed a joint venture and were successfully appointed as the team’s Sustainability Consultant. They were to document the process from start to finish, advise the design team on sustainable solutions and manage each step of the certification process.

Initially, Nedbank Namibia’s new head office achieved a 5-star Green Star Office Design certification. As the building was only three points shy of a 6-star rating, the sustainability consultant advised on the additional measures required to realise a 6-star rating. The client gave the go-ahead, and these measures were implemented to achieve the 6-Star Green Star As-built certification.

Marloes Reinink, director at Solid Green Consulting, says that the entire certification process required vision and dedication from both the client and professional team. All professionals and contractors had contractual obligations and targets to implement, track and report on throughout the Green Star processes. Elri Syfert from WCE was the Accredited Professional on the project and assistance was provided by Annelide Sherratt from Solid Green’s side. WCE also assisted Nedbank in procuring an independent commissioning agent to ensure that future maintenance was properly considered during the design process, and that all systems were correctly commissioned before handover.

The Nedbank Head Office Campus in Windhoek, a visually striking sixteen-storey building located at Freedom Plaza on Independence Avenue, is characterised by strong contemporary geometries.

Furthering industry knowledge and capacity

 The 6-star certification is reserved for highly efficient buildings that also address social issues and contribute to the community. Martha Murorua, Managing Director of Nedbank Namibia, mentions that the achievement showcases the quality of Namibian workmanship.

“Our new head office is a symbol of our commitment to supporting the local economy and creating job opportunities for the people of Namibia,” Murorua says.

With 97% of the contract value allocated to Namibian companies, this building showcases the collective positive impact we can have on empowering and supporting local capacity development.

Furthermore, as part of the innovation points achieved on the project, all major contractors, sub-contractors and consultants completed the GBCSA online course for New Buildings. This elevated the understanding, knowledge and capabilities around sustainability within the Namibian market, and set a benchmark for future developments in this respect.

External louvres act as dynamic façade elements and passive shading devices to limit glazing and heat loads.

Landmark sustainability

The visually striking sixteen-storey building, located at Freedom Plaza on Independence Avenue, and covering a total gross floor area of 10,716m², is characterised by strong contemporary geometries. The ground floor accommodates Nedbank’s public entrance and client interface, client service and a coffee shop.

Energy modelling was carried out by Solid Green very early on during the concept design stage. The intention was to identify design measures that would reduce energy consumption. The most significant design changes resulting from this process were:

• changing the East and West façades from solid panels to etched glass, reducing heat load gains by 50%.
• external louvres acting as dynamic façade elements and passive shading devices to limit glazing and heat loads.
• double glazing to the East, West and North façades, which also assists with noise reduction.
• a split between perimeter and internal office heat load zoning.
• blinds on the North façade to allow for better glare control.

The modelling also identified that, by increasing the size of the photovoltaic system on the roof, the reduction in greenhouse gas emissions would be significant enough to permit the building to target a 6-star As-built certification.

For Rowan McNamara, Director at Kerry McNamara Architects and his design team, the process of achieving a 6-star rating has been very rewarding.

The experience has been unsurpassed in expanding our knowledge and commitment to sustainability and green building. A unique and interesting process was the 3D simulation and finetuning of the façade louvres and performance glazing with the team at Solid Green Consulting. This allowed us to achieve excellent external views for the occupants whilst maintaining thermal comfort and energy efficiency. We are very proud to be a part of this sustainable landmark in the Namibian built environment landscape and congratulate all involved in this achievement.

Energy modelling carried out by Solid Green allowed the design team to achieve excellent external views for the building occupants whilst maintaining thermal comfort and energy efficiency.

Innovations and resource savings

Of the 1,600 tons of reinforced steel used for the building structure, 92% consisted of recycled metal to minimise the embodied energy and resource depletion associated with the use of virgin steel. In addition, the use of Portland cement was reduced by an impressive 47%, by substituting fly ash that came from power stations. And 93% of waste generated during construction was recycled.

Peak electrical demand was reduced by 30% due to the installation of the PV system, with an annual production of 262.8MWh. Energy modelling further established that the energy efficient design and the addition of the PV system achieved a 40% energy saving compared to similar buildings. In total, carbon emissions associated with operational energy consumption have been reduced to 27.1 kg CO2/m²/year from 272.6 kg CO2/m²/year – a 90% improvement compared to a conventional building of this type.

Energy efficient initiatives include the installation of 100% LED lighting as well as a lighting control system that allows daylight harvesting – when the light outside is bright, the lights inside will dim, saving electricity and reducing glare in the office space. To further improve occupant wellbeing and productivity, fresh air is supplied at 33% above the minimum required by the SANS building regulations for conventional buildings.

 Submetering of all substative energy and water loads is in place, and a building management system records energy and water consumption for monitoring, reporting and tuning. In addition, energy and water data is displayed as a learning resource in the building reception area to inform users and visitors about resource consumption.

Rain water and airconditioning condensate is collected, treated and stored, together with treated water collected from sinks and showers. Topped up with ground water collected from a sump, this water is then pumped to the roof and used for toilets, irrigation and façade cleaning. In this way, the building uses 20% less water from the municipal supply and 50% less water ends up in the municipal sewer system.

Another exciting feature, and one where Innovation credits were awarded, is the Sun Cycles Innovation. A small shop has been set up in the basement where employees as well as tourists can rent a Sun Cycle e-bike to be used in the Windhoek CBD for short business trips and city tours. Cycling facilities with showers and lockers have also been included to promote sustainable transport. In addition, a green cleaning policy has been implemented to address environmental best practices for cleaning the interior of the building. The building’s waste is also being monitored and reported each year, so that waste reduction targets can be established.

In conclusion

Murorua believes that Nedbank’s commitment to sustainability and positive social impact puts the bank among world-class leaders in building practices, setting an inspiring example of what can be achieved through collaboration. She concludes, “The 6-star rating is testament to our collective dedication and perseverance. Let’s keep pushing forward towards even bigger achievements.”

Project Team

Owner: NedProperties (Pty) Ltd
Sustainability Consultant & Accredited GBCSA Professional: WCE Consulting Engineers / Solid Green Consulting
Project Manager: Emcon Consulting Group
Architect: Kerry McNamara Architects Inc.
Civil & Structural Engineer: WCE Consulting Engineers
Electrical & Mechanical Engineer: Emcon Consulting Group
Quantity Surveyor: Herselman Van Greunen Quantity Surveyors
Independent Commissioning Agent: Ecolution
Main contractor: Namibia Construction (Pty) Ltd