Low carbon design aims high

Atkins | 03 Dec 2014 | Comments

Smart buildings and a fresh approach to urban planning could herald a brighter future for the world’s fastest-growing cities.

With its sleek lines and gleaming glass façade, the H2 low carbon building in Tianjin, China, radiates neo-modern kerb appeal. But the beauty of this building is more than skin-deep. Completed this year, H2 – a mixed-use development which includes offices, shops, restaurants and exhibition spaces – is one of the most energy-efficient buildings in the country.

This achievement was in the spotlight recently when H2 received an award in the “Best innovative green building” category of the 2014 MIPIM Asia Awards, which recognise innovation and achievement in the region’s property industry.

The nine-storey block is the low carbon centrepiece of the Modern Services District of the Tianjin Economic-Technological Development Area (TEDA), about 80 miles south-east of Beijing. H2 is accredited to four different green certification rating systems and is the first office building in the world to achieve this distinction.

In addition to its role as a commercial building, H2 is designed as a showcase for green building technologies – all the way from its low carbon basement demonstration area to its 50-metre high landscaped roof garden, which helps keep the building cool in summer.

Atkins provided master planning and architectural design services for the project, as well as coordinating all the stakeholders to ensure all design intentions were implemented and embraced during the build. Atkins’ architectural department in China has more than a dozen projects under construction.

H2 reflects China’s growing determination to halt the environmental damage that has beset its economic expansion over the past 30 years. Increasing interest in green certifications – which exceed the minimum energy efficiency standards laid down by governments – testifies to that commitment. The green building schemes under which H2 is accredited are China Three Star, CASBEE (Japan), BREEAM (UK) and LEED (US).

Green labelling schemes such as these provide independent recognition of not only a building’s low carbon and resource efficiency credentials (including aspects like energy, water, and biodiversity) but also its ability to provide a comfortable, safe and attractive environment for the people who work in it.

The schemes take into account factors such as indoor air quality and comfort, the availability of daylight and a view out of the building. Focusing on these quality of life attributes is good not only for building users – workers in green buildings tend to be healthier – but also makes business sense, because productivity is higher. All these factors help to attract investment from overseas.

“Multinational companies, such as banks and law firms, want to know that a building is going to perform to the standards they are accustomed to in Europe and the US,” says Sean Lockie, director, carbon and sustainability, Faithful+Gould. “If you’ve got people all over the world, you want to make sure they’re in accommodation with similar performance standards. Organisations want spaces that perform predictably, and green rating systems help with that.”

Building to green benchmarks often means striking a balance between environmental objectives on the one hand and user comfort on the other. Achieving that balance can be tricky. For instance, some of the things that make life better for occupants – such as a good view out of the window – can lead to increased energy consumption through greater heat loss of solar gains, if they aren’t designed correctly.

Predominantly west facing buildings, for example, are exposed to the full force of the afternoon sun. This exposure increases the need for energy guzzling air conditioning.

“Factors such as the orientation and shape of the building have an impact on energy efficiency, but often the view out of the building is important,” says Peter Chan, technical director for sustainable building design at Atkins.

Getting the balance right depends on multidisciplinary collaboration. “Atkins’ architectural and engineering teams work together from the start,” says Chan. “We wouldn’t ask the architectural team to alter the orientation of the building, but we would advise them on design measures to minimise solar heat gains, such as shading devices and double/triple glazing systems.”

In the case of H2, the decision was taken to orient the building’s long axis to face south. This orientation helps in two ways.

First, it maximises natural light for people working in the building.

Even people whose desks are set some distance from the windows get the benefit of daylight, because of horizontal “light pipes” that channel natural light into the building.

Second, a south-facing elevation is ideal for harvesting solar energy. H2’s photovoltaic array is an integral part of the building’s façade and can generate 60kW – enough to power around 300 PCs and monitors when the sun shines.

The north face of the building is triple glazed to minimise heat losses during the icy Tianjin winter. The project is described by the design team as an “ecological sandwich” – a reference to the building’s distinctive rectilinear profile and multi-layered curtain walls.

The H2 low carbon building in Tianjin, China.

Green buildings such as H2 can be more expensive to design and construct than conventional structures, but not all green buildings cost more. Research cited in a recent World Green Building Council report suggests that the cost premium for a green building over a conventional code-compliant one is in the range of -0.4 to 12.5 per cent.

But these upfront costs can be recouped. H2, for example, is designed to use 30 per cent less energy than a conventionally designed building, so running costs are lower.

“When you look at economics in terms of sustainability, you need to consider the life-cycle costs of the building, including the operational cost,” says Chan. “A green building might cost more initially, but there are huge operational savings throughout the life of the building. So if you look at the whole-life cost, it actually saves you money.”

Smarter buildings are integral to the greening of cities, but they aren’t the end of the story. What happens between buildings – and beyond them – also has significant implications for sustainability. New approaches to planning are helping to minimise the negative effects of urban development, and to create more attractive and liveable cities.

“Planning sets the die for what will happen further down the line, and it has the single greatest influence on overall carbon reductions,” says Mark Hewlett, associate for low carbon and sustainability at Atkins. “The scale is important in terms of what you can achieve in integrating urban planning and design, transport and utility infrastructure provision. What we are doing at Atkins is creating new planning approaches that link in with what we do in other areas, using a highly integrated, holistic approach.”

Launched in May this year, Atkins’ Eco-Low Carbon (ELC) urban planning methodology was developed with funding from the UK’s Foreign and Commonwealth Office and co-funding from the Chinese government. The central role of urban planning, with “front loading” of ELC approaches and methods from the earliest stages of the urban planning process, is increasingly recognised as vital in implementing the vision of China’s National New-type Urbanisation Plan (2014-2020), released in March this year.

The ELC urban planning methodology is closely aligned with Atkins’ global Future Proofing Cities (FPC) initiative. The FPC approach provides city planners and managers with a holistic, integrated, solution-focused framework to address the key global challenges of the 21st century of human induced climate change, resource scarcity and ecological degradation and to develop truly sustainable cities. FPC concepts and methods have been adapted and tailored for Chinese urban planning based on international and Chinese best practice.

“In essence, for urban planners ‘eco’ means open space and ‘low carbon’ means buildings and infrastructure, including transport,” says Hewlett. “One of the key things we focus on is the relationship between land use and transport, because a lot of urban sustainability issues revolve around optimising the relationship between these two fundamental elements of the plan.”

Open space planning is a vital part of the equation. “Increasingly, this is focused on trying not only to protect areas of high ecological value, but also to incorporate and enhance ecological assets of different types within the plan, with a strong emphasis on climate responsive and context sensitive approaches,” says Hewlett.

The many benefits of multifunctional green spaces in cities include recreation and general amenity, higher land values, enhancing biodiversity, providing shade and wind breaks, reducing urban heat island effects, improving water quality and reducing the impact of surface water runoff in drainage systems. And attractive, intelligently planned open space encourages the uptake of “slow transport” – walking and cycling – rather than carbon-intensive car journeys, with additional health and well-being benefits.

“If your land use supports a lower carbon transport network, you’re typically looking at a 30 per cent or more potential reduction in transport related carbon emissions straight off the starting block, compared with a plan that isn’t optimised,” says Hewlett. “Ecolow carbon approaches can have impressive benefits. It’s just a question of plotting the right path. The ELC urban planning methodology provides clear, practical, step-by-step guidance for hands-on use as an everyday working tool, designed to be fully integrated with the Chinese urban planning system.”

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