There is a written environmental policy, objectives and targets for performance. NMEC has been toiling to make travelling to the Dome easier and greener. Water use, too, has been targetted as a chance for NMEC to show off its sustainability credentials.
Even the choice of material for the Dome's skin is now hailed as an environmental victory. By rejecting pvc in favour of a less damaging, more durable, fabric, even the green pressure groups would be proud of the structure. Or would they?
The Dome scores highly for bringing a derelict site back into constructive use. The ground had been contaminated by the gasworks that once stood in this part of the Greenwich peninsula.
It makes good environmental sense, therefore, to redevelop this unwanted, run-down part of London. It makes good political sense too, given the government's intention of building on brownfield sites wherever possible.
Fifteen acres of the site are to be set aside for landscaping, as an attractive backdrop for the Dome. The NMEC is also trying to encourage wildlife into the riverbank area by constructing an 'ecological terrace' with native plant species, and nooks and crannies for birds and animals to make their homes.
The Dome was originally intended to be up for five to seven years, with the main emphasis on the 12 month life of the millennium exhibition. Tony Blair's decision last year to make the Dome a permanent legacy changed that, but by then many key design decisions were already set in stone.
Building services have been conceived as a short-life project – designers thinking no more than five years ahead. They have been hamstrung by not knowing how the building will be used after 2000, and have made the best of a bad lot by designing in enough redundancy and flexibility to leave most options open.
It seems likely that much of the services infrastructure will be ripped out after the exhibition. Much of the m&e plant could be removed before the end of its useful life.
Ordinarily this would be a far cry from the best environmental option. But here, components were chosen for resale when the exhibition ends. Ken Carmichael, building services team leader, says standard, packaged plant was specified with this in mind.
He sees good prospects for reselling hv switchgear, chillers, air handling units and transformers, with possible sales of pumps and standby generators.
The NMEC even checked with the City that there was a second-hand market for the key items of plant they chose before making purchases.
Partly as a consequence of the 12 month design horizon, the Dome will use electricity instead of gas to stabilise temperatures. A one year life supposedly did not warrant investment in gas infrastructure for heating and cooling, so gas will only be used for catering.
Using electricity presented an additional advantage in the shape of quicker installation – waiting for new gas mains would inevitably have held up construction.
No estimates have been made of total energy consumption in the Dome, says Gregor Harvie, NMEC's environmental coordinator and 'troubleshooter'. He claims that so long as the services for exhibition spaces remain an unknown quantity, it is impossible to offer even a ball-park figure.
Dome wall material and its performance
The Dome wall has been made from a woven glass fibre. This is coated in polytetraflouro-ethylene (ptfe or teflon) – one of the most expensive plastics you can buy. The coating used for non-stick pans, ptfe was chosen deliberately so that the Dome would clean itself.
This combination of woven glass and ptfe is also a very durable material. The NMEC reckons it will last for 30 years. After this, Buro Happold engineers say it could be replaced by a new, even longer lasting material.
However there are three downsides to the material. First, it will not biodegrade at the end of its life, making it unsuitable for use as landfill. Second, its manufacture is very energy-intensive. Third, environmental watchdog Construction Resources says that, although it can normally be recycled, this will probably not be possible for the Dome's ptfe because it is bonded to glass fibre.
The double-layer skin used for the Dome wall was chosen largely because it stops condensation forming on the outer wall from falling upon visitors' heads. It also has the extra advantage of providing some thermal insulation, trapping up to 700 mm of air.
Gregor Harvie claims that about 10% of the sun's light will penetrate the Dome's skin – some 3000 lux on a bright summer day ie enough to warrant wearing sunglasses.
This focal point for millennial celebrations could have a massive impact on the environment.
Water use and recovery
The Dome wall offers another major opportunity for an environmental home run: a built-in rainwater collection device. With an area of close to 10 000 m2, the Dome roof has an enormous potential to collect water in a storm. Just as we should be saving energy wherever possible in buildings, so too there are pressures to save and reuse water. Particularly if current climate change predictions prove correct, and South East England does become drier. Droughts will be more frequent and we will be forced to do more to cut water use.
To pre-empt such concerns, the Dome and associated buildings will be fed with recovered water, collected from three sources:
Thames Water and the NMEC are jointly designing the water supply systems to deliver 500 m3 of potable water per day. This will meet the Dome's entire water needs for flushing toilets. A further 500 m3 of potable water per day will be supplied by Thames Water for all other purposes.
The recovered water will be treated using biological aerated filters, membrane filtration, plus chlorination. While this may sound like overkill for simply flushing the loo, Thames Water says it is necessary to kill pathogens and prevent biological regrowth in the water distribution system.
Specially designed reedbeds, situated between the Dome and the Thames, will purify rainwater from the roof before chlorination. Peter English, NMEC's Dome development manager, says that after treatment the recovered water will actually be "better quality than the water drunk in many parts of the world."
Transport and waste management
Visitors to the Dome will hopefully make full use of public transport options: buses, trains into nearby Charlton, riverboat from central London, coaches, and tube trains to the Jubilee Line Extension. The NMEC hopes that motorists will use park and ride facilities on the north and south banks of the Thames.
No car parking places are to be provided for visitors to the Dome. What other large-scale development can boast such a solid commitment to more sustainable forms of transport? It presents a stark contrast to the supermarket being built in the nearby Millennium Village, where 850 parking spaces are planned.
Cycling will not be left out of the transport equation. The Dome will be on the Sustrans route along the Thames, a bike park is planned, and the London Borough of Greenwich is putting up £0.5 m for signposting to the Dome.
But – and this is a big but – the majority of the Dome's 12 million visitors will be travelling from afar. Some will travel to Greenwich from abroad, by aeroplane, with the massive energy cost this entails. Others will inevitably drive as close as they can get to the Dome, choking south east London's roads.
NMEC itself estimates only 1% of visitors will arrive by bike or on foot. So simply in getting there, most will use limited fuel resources and add to CO2 emissions.
As well as transport issues, NMEC has spotlighted waste for attention. NMEC's Environmental Bulletin proclaims that it is "declaring a war on waste." However, it has scant detail on lines of attack, suggesting that the waste battle plans have yet to be drawn up.
Putting the Dome into context
The government says sustainable development includes "Effective protection of the environment; acting to limit climate change, protecting air quality and landscapes." It also involves "Prudent use of natural resources like oil, gas and water1." The Dome's sophisticated water recovery systems and its objective of educating visitors about sustainability are commendable. Reusing this tract of contaminated land is similarly beneficial and worthy of praise.
It may divert development from other schemes and so "protect landscapes" indirectly. It may also help to regenerate this part of London. Bringing employment and investment to a depressed part of the city also counts as a laudable stepping stone to sustainability.
However, building what amounts to a massive tent, heated and cooled using electricity, and intended to attract 12 million people per year, could hardly be considered a "prudent use of natural resources." There was always an irony in a building designed for only 12 months use laying claims to being "sustainable." Now it looks set to be permanent, those claims seem even more dubious.
Is the Millennium Dome a friend of the earth?
"Some of the worst 20th century mistakes have been repeated on this supposed flagship 21st century site. Muddled, ill-conceived and rushed through, [the Greenwich millennium site as a whole] does not represent sustainable regeneration.” This is the verdict from Jennifer Bates’ detailed investigation into the Dome and the redevelopment of the Greenwich peninsular2. Bates is Friends of the Earth Greenwich’s spokesperson and resident Dome expert. She also cites evidence that the cost of the millennium exhibition could provide “a home for all the UK’s homeless, a hospital bed and a nursery place for all who need one.” Moreover, she claims that theDome itself is set to become “a glorified trade fair for the sponsors – and a part lottery-funded one at that!” However, the FoE has welcomed the use of recovered water in the Dome, a riverboat transport system, walking/cycling provision, and NMEC’s plan to make the dome itself a car-free zone – although Bates contends that more could have been done to improve transport facilities. Not wishing to throw stones without offering solutions, FoE have made a series of recommendations related to the Dome’s building services:Source
Building Sustainable Design
Reference
1Department of the Environment, Transport and the Regions, Opportunities for change, 1998. 2Friends of the Earth Greenwich, The Greenwich Millennium Site: how not to regenerate Britain, (being compiled).
