Due to its location in the CBD, the building – which has eight floors and a GFA of 8720sqm – is well connected to local amenities and existing public transport infrastructure, and offers proximity to accommodation for staff or visitors. This enabled the project to achieve a high score under the Green Star Transport credits.

Zendré Compion, Senior Sustainable Building Consultant at Solid Green, explains that organisations should consider sustainability at the earliest stages of a new office project. “Choosing an existing building over a new building has major implications,” she says.

The impact of new construction, with the associated waste and urban sprawl, is significant. Green Star therefore rewards refurbishment projects for reusing as much of the existing building as possible, in this case the whole structure and façade; as well as for ‘Reuse of land’ under Land Use and Ecology, and for not impacting topsoil. In this instance, the building’s contribution to revitalising the city centre was also considered.

Compion adds that refurbishment projects are also rewarded for reduced environmental impact through a slightly simplified set of criteria because the material value comprises less than 1% of the contract value, so a number of the Green Star material credits fall away such as timber, concrete and steel.

While older buildings may be a challenge on some fronts, a potential benefit to refurbishment is that many of them were designed with good passive design principles – a practice that was slowly eroded as building thermal comfort became increasingly easy to manage with automated systems. In this case, the NERSA building has smaller glazed elements, large overhangs, external vertical blinds where the afternoon summer sun hits the building, and narrow floor plates.

A key focus for the refurbishment was the upgrading of the building’s major mechanical and water systems – which made it possible to target Indoor Environmental Quality (IEQ), Energy (ENE) and Water points. Energy modelling of the refurbished building design was carried out and the results indicated an improvement of 42% in Greenhouse Gas Emissions associated with operational energy consumption compared to a notional building model.

Energy uses of 100kVA or greater and all major water uses are sub-metered and managed through an efficient energy management system. Upgraded roofing insulation will improve the indoor thermal comfort and reduce the amount of energy used for building cooling; and internal blinds have been specified on all windows to reduce daylight glare. A total overhaul of building mechanical, electrical and wet services has improved energy efficiency. The outdated mechanical equipment was replaced by a VRF system, improving the system COP and general performance. In addition, hot water for amenities is heated using a heat-pump, thus improving efficiency and saving electricity.

Occupancy sensors were positioned throughout the circulation and common areas as well as bathrooms and storerooms, and energy efficient lighting was installed throughout the building. The lighting design was also updated to include efficient luminaires that provide appropriate lighting levels with much reduced energy consumption.

Potable water consumption has been significantly reduced through the installation of dual flush and low flow sanitary fittings, and rainwater harvesting for toilet flushing. Waste collection and recycling is being undertaken by waste and recycling service providers, with measures being put in place to improve the rate of recycling – such as the provision of confidential paper bins for white paper; flattening and storing of cardboard boxes; and the separation of wet waste (mostly from the canteen) from recyclables and landfill.

To inform occupants and users of all the building’s incorporated service and management systems, a Building User Guide was compiled, and educational material has been provided on a screen in the building foyer to communicate water and energy consumption data with occupants. This will enable the facilities management team to optimise the building’s environmental performance and minimise its environmental impact; and will go a long way to ensuring that all future alterations, additions and program changes are consistent with the intent of the purpose of the Building Users’ Guide and the health of the environment.

Compion explains that there were a few challenges in the Green Star certification process.

When working with an older building, with no physical extensions or additions and alterations, there was no room for targeting points through innovation. There were also some challenges in getting all the existing building information from old drawings. And logistically, the tenants remained in the building during construction so the refurbishment had to happen floor by floor, which made the process relatively slow and caused some discomfort to the building users at the time.

That being said, we are looking forward to see many more refurbishment projects in the future and hope that clients can make the leap to think of the sustainability of their building projects early in the design process. This is one important way in which we will be able to reduce overall construction sector impacts, and further revitalise inner cities.

The post NERSA’s existing building achieves 4 Green Stars appeared first on Solid Green Consulting.

Image credit Abland.

“The HVAC system implemented therefore provides a high proportion of good quality outside air,” she explains.

Smoking inside the building is prohibited; and only interior finishes with low Volatile Organic Compounds have been specified for the fitout. In addition, all gaseous and fire suppression systems and thermal insulants used have an Ozone Depleting Potential (ODP) of zero.

An energy model was generated in the design stages of the building to ensure that thermal comfort levels are within the ASHRAE Standard 55-2004 Acceptability Limits for at least 98% of occupied hours. Various energy initiatives were implemented to reduce the overall energy consumption of the building. All individual spaces or enclosed spaces are individually switched with occupancy sensors to offer greater flexibility for light switching; and care was taken to ensure that the office lighting is not over designed, and that artificial lighting with minimal energy consumption was specified.

Image credit Abland.

This reduction in operational energy consumption will ensure that Greenhouse Gas Emissions are minimised during the building’s lifecycle. As data gathering is essential to assessing opportunities for energy savings, sub-metering of major energy consuming systems was implemented.

Sub-metering of major water consuming systems is also in place. The building was designed to reduce the consumption of potable water for the building’s fire protection and essential water storage systems; and occupant water usage was limited to 0.4L/day/m2 thanks to the specification of water efficient fittings.

Image credit Abland.

Project specific Environmental and Waste Management Plans were developed and implemented during the construction phase to establish guidelines that minimise the environmental impact associated with construction activities, and to minimise the contribution of waste going to landfill.

As transparency in terms of perceived Green Building premiums is extremely important to help drive sustainability in the sector, Lakeview Phase II completed the financial transparency criteria to assist the GBCSA with market research and to help create a broader public awareness around the actual cost of Green Buildings.

“Nedbank has once again confirmed its dedication to driving green building in the property sector by committing to both 4-Star Green Star Office V1.1 Design and 5-Star As-Built certifications. This includes operational benefits expected from 45% energy savings compared to an average office building,” Sherratt concludes.

Collaborating with a client and professional team who share a common vision has made the certification process that much easier and has allowed each professional to push for sustainable solutions within their area of expertise, resulting in the significant achievement of the 5-star rating in As-Built.

Project Team

OWNER & CLIENT: Nedbank
DEVELOPER: Abland
ACCREDITED PROFESSIONAL & SUSTAINABLE BUILDING CONSULTANT: Solid Green Consulting
ARCHITECT & WET SERVICES: MWLF Architects
ELECTRICAL ENGINEER: Claassen Auret
FIRE ENGINEER: IFE SA International Fire Engineering
LIFT SPECIALIST: Quality in Motion
MECHANICAL ENGINEER: Spoormaker & Partners
QUANTITY SURVEYORS: Quanticost
STRUCTURAL ENGINEERS: WSP
MAIN CONTRACTOR: Tiber
PROJECT MANAGER: Morta Project Management
LANDSCAPE DESIGNERS: Connie Pretorius Landscaping
IRRIGATION CONSULTANT: Controlled Irrigation

The post As-Built certification for Lakeview Phase II appeared first on Solid Green Consulting.

Green building initiatives implemented since the design certification include ice storage, rainwater harvesting, and innovation credits. Says Annelide Sherratt, sustainability consultant at Solid Green and the accredited professional (AP) on the project:

Working with a like-minded professional project team, developers and client such as those on Lakeview Phase II, who share common views on sustainability, made the project a pleasure to work on and allowed each professional to push for sustainable solutions within their area of expertise.

The 12,542m2 office building consists of 4 office levels and 3 basement levels. The project implemented several environmental initiatives to improve wellbeing of the occupants in the building that in return contributes to enhanced work performance. Sherratt explains that:

As humans spend over 90% of their lives indoors, exposure to air pollutants can be far greater indoors than outdoors. The HVAC system implemented here therefore provides a high proportion of good quality outside air to counteract the build-up of indoor pollutants. The building prohibits smoking inside the building to further ensure optimum air quality; and only interior finishes with low Volatile Organic Compounds have been specified within the fitout.

To achieve a high level of thermal comfort for the building occupants, the building was modelled in a simulation program. Various energy initiatives were also implemented to reduce the overall energy consumption of the building. As the behaviour of the building occupants is crucial to the building’s energy performance, energy submetering was installed for all substantive energy uses within the building, to facilitate ongoing monitoring and management of energy consumption; and a Building Management System (BMS) was incorporated to actively control and optimise the effectiveness of building services.

Occupancy sensors are installed throughout the building to provide flexibility related to light switching and to prevent wasting energy in unoccupied spaces. The project also incorporates artificial lighting with minimal energy consumption, that provides optimum illuminance levels without being over designed. Hot water is provided by small high performance electric under-counter geysers installed in the kitchenette areas.

Overall, the project design and building services achieved a 45% improvement in Carbon Emissions over a SANS 204 notional building through energy modelling. Chilufya Lombe, director at Solid Green Consulting, explains:

The building has reduced its peak electrical demand by providing an ice storage system for the chiller plant. Instead of having a large chiller, a combination of a chiller and an ice storage facility has been designed. This system allows the building to have a chiller that is 50% smaller than a conventional building. The ice works as a thermal storage device: at night, the chiller runs to create ice and, during the day, this ice is used for the cooling system to supplement the chiller.

Additional sustainability initiatives were implemented that focus on the reduction of potable water consumption, with the aims of easing demand on municipal water sources as well as contributing to more cost-efficient operations of the building. Water efficient sanitary fittings have been specified that help occupants to use water sparingly. Sub-metering for major water consuming systems is in place, to detect any leaks so that little to no water is wasted. Rainwater harvesting has been incorporated as an alternative water source for landscaping; and smart irrigation systems and indigenous landscaping have been incorporated to use water as efficiently as possible.

Innovative sustainable initiative, over and above what is required by Green Star, have also been implemented for the project. The developer committed to certifying the project with multiple ratings – both Green Star Office V1.1 Design and As-Built certifications. As transparency in terms of a Green Building Premium is extremely important to help drive sustainability in the building industry, Lakeview Phase II completed the financial transparency criteria that will assist the GBCSA with market research and inform the public regarding the cost of Green Buildings.

Making a difference in the Sustainability sector is to consistently lead by example and motivate for change,” Sherratt concludes. “Through the commitment and close collaboration of the developer, the client and the professional team, Lakeview Phase II successfully demonstrates how an office building can drive excellence in the South African construction industry.

For more information about this project, see the project page for Lakeside Phase II.

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