The rise of eco-towers

  • 22nd November 2016|
  • eco-towers|
  • green architecture|
  • skyscrapers|
  • sustainability|
  • sustainable cities
  • |Mark Heptonstall

The United Kingdom is not staying behind, with London’s Strata, The Shard, Pan Peninsula Tower and several others in the pipeline. But are these luxury residential skyscrapers truly sustainable?

Sustainability, or the reflection of the upper class aspirations?

New green skyscrapers are mushrooming across London: there are now 233 high-rises approved and waiting to start construction. The demand is strong and there is serious money to be made: buyers are ready to pay a 31% premium to secure a view of the capital, while a river view can add 9% to the property value.

But eco towers are spreading beyond the capital – The Beacon, the flagship residential development in Hemel Hempstead is the perfect example of this trend. Described as ‘iconic landmark,’ the proposed 16 storey tower will contain 208 apartments, a gym, leisure facilities, coffee shop, green roof, internal arboretum (!), a community meeting room, a digital library with free public computer access, premium offices on the ground floor and an underground parking.

The dwelling is designed to achieve EPC rating A+, which is reserved for carbon neutral buildings. The tower will be equipped with two 60KW ground source heat pumps and air-source heat pumps along with VRV air-conditioning to heat the offices, gym and reception areas. These technologies will be integrated with a CHP boiler and closed vented system to provide both heat and hot water. This solution will cut CO2 emissions by 70% compared with a standard design installation, according to Lumiere Developments, the company standing behind the project.

The Beacon exterior will feature Building Integrated Photovoltaic Panels (BIPV), creating a ‘solar ledge’ running around each level of the building and creating the highest density solar farm in the country, the company claims. The PV system will generate 50% of the building’s net electricity (after considering net annual export/import).

The most distinctive feature, however, will be a large internal arboretum with tropical trees. Covered with BIPV panels, the design is intended to create a greenhouse effect within the dwelling and minimise heat loss. In buildings, the common areas, such as corridors, usually feature lower temperatures than flats. This difference leads to loss of heat. In contrast, the Beacon is designed to achieve the zero temperature gradients: the heat generated from ground source heat pumps and radiant heat from the sunlight will rise the temperature in the common areas to the level of the temperature in the flats. This strategy is expected to cut energy wastage by 10%.

To add more greenery to the building interior, each floor will be surrounded by a balustrade containing living plants.

The dwellings will use energy efficient LED lights with PIR switches. In communal areas, the switches will have long delays, which will result in a 70% reduction of lighting usage when compared to standard lighting technologies and strategies.

The Beacon windows will be made of triple glazing, coated with anti-reflective film reducing the absorbance of the direct sunlight by as much as 25% to keep the dwellings’ interiors cool.

Each flat will be equipped with combined heat and power boilers, double panel fin radiators with digital programmable thermostatic radiator valves (TRV’s), A+ rated appliances, as well as energy saving wall sockets with remote switches, allowing appliances to be switched off rather than being left on standby.

NEST/HIVE or similar programmers will be used to lower the temperature when the flats are empty and rising before the residents are to return, reducing the heating needs by an estimated 10%.

The Beacon will also feature advanced water saving and reclamation solutions. The atrium roof and green roof will be inclined to facilitate water collection. The collected water will be used to irrigate plants at each floor level, an arboretum on the ground floor and the green roof during prolonged dry spells.

Recycling points will be located on each floor and electric cars and electric bikes will be available to residents for hire. The car park will be automated and cars parked by a robot.

The list of green features is impressive, but also a bit overwhelming. When some solutions (such as ground source heat pumps, PVs, LED and others) sound as a good choice, the others, like on-floor planting schemes, or most of all, an internal arboretum housing palms, orange and apple trees are more difficult to justify. Such complex systems are very expensive to build and operate. Are they necessary? Do they deliver tangible benefits? Or are they just meant to attract affluent clientele ready to pay extra price for such luxuries and raise the developer’s profits?

Moreover, the complexity of such systems increases the risk of failure. It is good when everything works well and according to the design, but when one important element fails, the entire experience could be easily ruined. What if the water collection system develops a fault, for example? The residents will be left with a building filled with dying plants? Similarly, automated parking might be necessary in London city centre, but not in this location; it is expensive and high maintenance.

There are known cases when the technology intended to impress, created a bitter disappointments among the residents instead. It happened when the build-in turbines in the London’s Strata (designed to help heat and cool the building) were not turning when the building first opened. One of the residents described his experience then as ‘living in an eco-experiment that went wrong’.

Sustainable, but for whom?

The social aspect is another issue rising controversy around green skyscrapers. There is not a sustainable city without social cohesion, experts say. But the vast majority of the planned and already under construction eco towers are luxury ones and therefore they do not contribute to solving the problem of affordable housing shortages.

Apartments in refurbished South Bank Tower range from around £2 to 20 million. In Strata, a two-bedroom apartment will cost you around £1 million. A studio flat in Pan Peninsula Tower is under £400,000, but if you are after a duplex one on the highest floor- the price rises close to £2 million. And outside the capital there is not much cheaper. In the Beacon, prices range from £218,000 for a starter home to £1 million for a penthouse.

Eco-towers are, in practice, private vertical cities operated as safety deposit boxed by foreign investors, some claim. And because of their elitism and exclusivity, eco-towers contribute highly to social schism creating more harm to local communities, than benefits.

Balancing the pros and cons

The supporters of green skyscrapers do not agree. New eco-towers become the landmarks, positively transforming the physical landscape in which they are present and deliver high quality homes, they argue. They are also good for the neighbourhoods raising the property prices and driving economic activity in an area. In the London’s South Bank district, for example, 100% of new residential towers built in the last decade have either introduced or financed additional public and or green space. Also, nearly 80% delivered extra office space while 67% created additional retail space.

Eco-towers advocates also point skyscrapers, when properly developed preserve and protect so valuable in urban environments green space.

Research suggests high rise buildings are the most sustainable form of urban development. They are criticised for high energy usage and greenhouse emissions production, but this is only a part of the picture. Yes, buildings in general ARE the highest contributors to CO2 emissions, but transport is the very close second.

If you build high rise buildings you get denser urban populations. In such environment, people are more likely to walk, cycle, or use public transport to get to work and around. Conversely, building lower dwellings and spreading them over a longer distance often results in much higher vehicle use. The study, conducted by the think tank New Climate Economy, concludes that taller and denser buildings can significantly reduce the cities carbon footprint.

Low rise building have larger land footprint. This means, more arable and other valuable land would be consumed by cities opting for lower density developments. The alternative is to expand the building footprint vertically.

Summary

The concept of green skyscrapers remains controversial. No doubt, living in an eco-tower is not for everybody. Some of us would never feel comfortably in such environment, the others would never be able to afford it considering current pricing levels. What are your opinions? Would you like to live in an eco-tower? What green features would you like to see there? (Or, maybe you live already? If so, please share your experience). Do you think there should be more residential high rise building constructed in the UK?

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