The newest addition to the United Nations Office in Nairobi (UNON) should be a real showcase of sustainability. Destined to host the global headquarters of the United Nations Environment Programme (UNEP) and UN-Habitat, it has the distinction of being one of the first energy neutral offices in Africa.
Construction work started in May 2009 and is due to be completed by the end of 2010. To keep the environmental impact to a minimum, it incorporates a range of green building techniques and uses local materials wherever possible. Efficient energy, water and waste management are key considerations in its design, the way it is built and the choice of equipment throughout. To meet the aspiration of 'energy neutrality', however, it also needs its own power source. So its rooftop array of solar photovoltaic (pv) panels has been specified to generate, on average, as much electricity as the building and everyone working there consumes.
By providing space for 1200 staff, it will meet most of the requirement for additional office accommodation at the UN's beautiful Gigiri compound near Nairobi, where the workforce is set to grow from 2500 at present (in more than 30 different UN organizations) to 4000.
Once completed, the building will have 16,500 square metres of usable space in four interconnected blocks, arranged around a central atrium. All cooling will be taken care of by natural ventilation. Green zones and wells of natural light have been designed in to the interior space, with the atrium's translucent roof allowing daylight to illuminate the central area. There will be solar panels to provide hot water, solar glass in the windows, and low energy lighting controlled by motion sensors. Waste separation, collection and recycling are well catered for, while the water management features run all the way from rainwater harvesting through water-efficient plumbing fixtures and dual flush toilets to the recycling of grey water and creation of an artificial wetland.
The 'energy neutrality' equation has been worked out carefully. Neutrality, as opposed to autonomy, does not mean that its solar pv system produces each watt of electricity actually consumed, but that its production over a full year equals or exceeds the building's total consumption. At night or on rainy days the offices will have to draw power from the national grid, since the pv system has no battery storage. At other times the system will be happily powering not just the new building but others in the Gilgiri compound too, and on most weekends there will probably even be a surplus going into the grid. Kenyan legislation does not currently provide for any kind of feed-in tariff, but, with electricity in short supply nationwide, this example may encourage a closer look at the case for changing those regulations.
The United Nations is funding the building's construction, at a total cost of approximately 1.4 billon Kenyan Shillings (USD 18 million). This includes fitting it out with the solar glass, low-energy lighting. water-efficient plumbing and so on. On the other hand it does not include the cost of the solar pv, for which there is a separate budget arrangement, with its capital outlay being paid back gradually over the life of the system out of operational savings.
The whole project has been an object lesson in the importance of careful planning and coordination, establishing common team goals to optimize sustainability outcomes, and helping to channel funding towards the areas with the greatest environmental, social and financial returns.
Every aspect of energy use is being scrutinized to identify possible savings. The two main areas are lighting (indoor, outdoor and security lighting) and office equipment (including computer workstations, servers and their cooling systems, and other IT infrastructure). On lighting alone, the potential for savings from energy-efficient lamps and motion sensor controls has been estimated at 193.325 megawatt hours per year, which equates to avoiding emissions of approximately 143 tonnes of carbon dioxide equivalent (tCO2eq).
The overall benefits include:
• an increased focus on sustainability
• a more inviting, congenial modern workplace for staff
• maximum use of natural light and air
• reduced office emissions, waste, energy and water consumption
• environmental, economic and social benefits for the region
• the development of local technological skills
• long term environmental benefits
• long term financial savings
Many of the measures being applied at Gigiri are relevant and replicable in other African countries. When completed, this should be an exemplar of sustainable building, an inspiration both for UN facilities worldwide and for new and existing buildings throughout Kenya and the rest of Africa. Achim Steiner, Director General of UNON and Executive Director of UNEP, sums up this ambition: “We want to show that it is possible to build a high standard international office, using renewable energy and minimising the environmental footprint, in a developing country in Africa, which meets or beats standard construction and operational costs.”