Fulton Mak – Updated on Feb 25, 2009 – SCMP
Green features are still hard to find in Hong Kong’s concrete jungle, despite the rhetoric on sustainable and ecologically friendly construction and mounting concerns about environmental protection.
The chief obstacles to going green highlighted in a number of surveys are perceptions among developers of higher initial costs and a longer payback period.
But the truth is that sustainable features are not necessarily more expensive and some are already being introduced with the promise of showing immediate cost savings, say supporters.
Structural auditing, they added, was one of the invisible green measures that could produce immediate results.
Simply put, structural auditing involves establishing a group of experts including structural engineers to vet a project proposal and recommend modifications or a redesign of a building’s structural framework.
The auditing process may be conducted not only on projects still on the drawing board but also on those already under construction, according to Hossein Rezai-Jorabi, group director at Web Structures, a civil, structural and geotechnical engineering consultancy.
“We have shown that it makes construction easier and more cost-effective. Average savings can total about 30 per cent of the structural cost of the building,” said Mr Rezai-Jorabi. “This translates into something like 5 per cent of total construction costs, including architectural fees.”
Helping clients minimise expenses is a priority, said Mr Rezai-Jorabi. In addition, the objective is to be at the forefront of the environmental protection movement and to reduce pollution.
By way of example, he said, through modifying the structural design, the use of steel reinforcement could be significantly reduced to between 100 and 150 kilograms of steel reinforcement per cubic metre of concrete, compared with an industry norm of 150kg to 200kg.
Such a saving would depend on the building’s structure, height, and the type of materials used, but the multiplier effect of the savings would help make significant reductions in pollution arising from producing steel and cement, as well as the transportation required to get the materials to construction sites.
An example of the green trend in construction is the newly built One Island East.
When designing and building this 70-storey commercial property in Quarry Bay, Swire Properties employed building information modelling and building life-cycle management to reduce costs and construction time, and to increase efficiency and reduce waste.
With the help of 3D design software, virtual buildings can be built and procured on a computer allowing identification of design co-ordination errors, reducing construction waste, and improving material procurement, labour resourcing and overall site productivity, according to a report by CLSA U, an executive education research programme of the brokerage and investment bank headquartered in Hong Kong.
This allows the team to eliminate 15 to 25 per cent of construction waste and reduce construction costs by 10 per cent.
Meanwhile, concrete crushers were used during demolition of the previous buildings on the site and a waste management plan was adopted to facilitate recycling, with the result that only 1 per cent of waste was disposed of in landfills compared with an average industry standard of 20 to 30 per cent.
The new building uses indirect office lighting designed with adjustable illumination levels that reduces energy consumption by up to 60 per cent, and extra large low-emissivity glazing panels that ensure maximum light penetration with minimum energy loss, heat gain and noise.
The result is that One Island East secured the highest platinum rating of the Building Environmental Assessment Method.