The Building and Construction Authority (BCA) will soon be updating its building regulations to include reflectivity requirements for all kinds of facade materials, said National Development Minister Khaw Boon Wan in a blog post yesterday.

This comes on the back of increasingly complex and elaborate building designs being introduced.

"With an increasing number of developers and architects exploring the use of less conventional materials, some form of check and balance is necessary so that design does not come at the cost of comfort and safety," said Mr Khaw.

Currently, such reflectivity requirements only pertain to glass. Under BCA's guidelines, reflective glass with a daylight reflectance exceeding 20 per cent is not allowed to be used on the external surfaces of windows, doors, walls or roofs.

"BCA's building regulation will be revised to include reflectivity requirements for all kinds of facade materials including metal roofs and metal cladding, as soon as the amended regulation is ready," said BCA yesterday.

The regulatory update is useful to ensure that new designs add to the neighbourhood, allowing residents, users and commuters to enjoy, without causing any inconvenience or hardship to anyone, said Mr Khaw.

To date, BCA has received feedback on 18 residential and commercial buildings regarding glare from sunlight reflected from the glass facade, metal roof and cladding of other buildings in the vicinity.

Other cities too are facing similar problems, noted Mr Khaw, citing the example of London's "fryscraper" building, so dubbed because it reflected so much sunlight that its rays could fry an egg nearby, and Hong Kong's International Commerce Centre (ICC). The impact of glare from ICC inconvenienced residents to the extent that it was the subject of debate in their Parliament.

Over in Sydney, regulations are in place to limit the daylight reflectance of all facade materials to 20 per cent. For buildings in the vicinity of arterial or major roads and Sydney Airport, there must be proof of light reflectivity, given safety concerns.