Why reward developers for building green homes but not the people who buy them? This is a question posed by founding members of the Professional Green Building Council, who are lobbying banks to offer special mortgage deals to buyers of flats it has certified as environmentally friendly when they start to go on sale next year. They want buyers to benefit along with developers who get incentives to include green features in their flats - although those benefits have been reined in recently after the government plugged loopholes in the scheme. 'This is a win-win proposal. While giving the banks more clients and the chance to make larger loans, the measure would help increase the demand for green homes that consume resources like electricity and water efficiently,' council director Wong Kam-sing said. He said close to 20 residential and commercial projects had already been registered for assessment by the council and the first certified residential estate - comprising more than 1,000 flats in Kowloon - is expected to be on the market by the end of next year or early 2012. Green mortgages, widely adopted by banks overseas, provide money to buyers at a lower interest rate and with reduced service fees for new green homes or second-hand ones that will have their energy efficiency improved. Last month, the Development Bureau announced that all new residential developments should go through a green assessment by the council from April next year, with the results included in brochures. Talks have already begun between the council and major banks, including HSBC, which has shown interest in launching green loans. 'We believe green purchases will make a positive impact on society,' an HSBC spokeswoman said. Under overseas practices, a green flat must achieve minimum environmental standards - in particular on energy consumption - set by governments or green building councils. As well as generating loan business and improving their corporate images, the banks receive government incentives, including tax breaks on the reduced interest. The green building assessment, conducted by anonymous engineers and architects of the council, looks at how the design of a development has improved the environment, including how much energy, water and waste will be saved. A certification with a ranking of platinum, gold or silver will then be given to the development based on its performance. 'The new policy gives a benchmark to banks and enables them to identify apartments that really contribute to our environment,' Wong said. 'Having created a supply of green apartments, it's time to stimulate demand for them to transform the market.' In Australia, where energy demand often peaks in winter, buyers engaged in green mortgages offered by Bendigo Bank are required to incorporate a minimum of two energy-saving designs in their homes, such as double-glazed windows to reduce heat loss. The deal offers a 0.5 per cent discount on the interest rate and waives the monthly service fee as long as the homes comply with environmental standards required in their states. In the United States, banks are encouraged to partner with the Environmental Protection Agency to provide energy-efficient loans known as Energy Star mortgages. More than 8,500 builders have enrolled in the programme and more than a million certified green homes have been built, according to the agency. Successful applicants can deduct the full mortgage interest from federal and state income taxes while lenders receive free marketing resources from the agency. TD Canada Trust, a bank serving more than 11 million customers in Canada, not only offers an interest-rate discount of 1 per cent, but also gives buyers a cash rebate of up to 1.5 per cent of their mortgage if they use certified kitchen appliances, solar panels and heating systems. But back in Hong Kong, none of the six major banks approached by the South China Morning Post - HSBC, Hang Seng Bank, Standard Chartered Bank, Bank of China Hong Kong, Bank of East Asia or Citibank - offered green mortgage deals. Both HSBC and Citibank said that they would explore the feasibility of such loans according to market developments. Chau Kwong-wing, chair professor of the Department of Real Estate and Construction at the University of Hong Kong, said green mortgages would be attractive only when interest rates were high. 'There would be no incentive for banks to launch it immediately, given the current low-interest environment. It will be more appealing when interest rates rise,' he said.