Enhancing the energy efficiency of buildings through the use of solar energy is just one of the ways building services engineers are helping to combat global warming. Hong Kong's appetite for development is criticised for not giving enough thought to the effect grand buildings may have on the environment. But attitudes are changing and more energy-efficient technologies are being adopted. Solar panels used with thermal storage techniques, the recycling of rainwater for flushing and irrigation, and devices to harness wind power are just some of the technologies deployed at the Electrical and Mechanical Services Department building in Kowloon Bay, which serves as a showcase for greener building service designs. 'The latest trend of the profession is towards sustainable design,' said Kevin Cheng, of the Hong Kong Institution of Engineers. 'We try to create healthier and safer indoor environments which use natural resources more efficiently. How to construct a building with less wastage that is more energy efficient, with more comfort and better safety, are all objectives of the building services engineer.' 'Light-piping' of natural light or the light sources of the upper-floors into the rest of the building can also reduce the electrical demand on a building's plant room. Further efficiency comes with sustainable design, for instance, in how the building's facade can transfer heat from outside to the interior, and the type of materials used. 'It doesn't mean we've done something very wrong in the past so that our buildings are not functioning efficiently,' said Paco Tang, lecturer in real estate and facilities management at Hong Kong Institute of Vocational Education. 'It's because we've gained knowledge from our experiences, so we have more resolve from university research institutions to make buildings more efficient and environmentally friendly. We have been using more energy efficient products in the past 20 years,' said Mr Tang. 'I wouldn't say we are leading here, but we are definitely not far behind.'