WHEN PEOPLE CHOOSE a hotel, they do not ask about the width of the walls or the general standard of soundproofing. But if a guest is kept awake half the night by a blaring television in the next room, or by other loud noises, such questions will come up very fast. Winston Suen, director of corporate engineering at Langham Hotels International, believes every guest should have a restful sleep, and that involves attending to details other people might overlook. 'We involve acoustic consultants at the beginning of a building project,' Mr Suen said. 'You can't rely on an architect for the acoustics, and failure to take noise issues into account can create a nightmare. Acoustics are affected by the design and the choice of the internal and external building materials.' Mr Suen is aware of the expectations of five-star guests and therefore ensures that the internal walls of group hotels effectively insulate one room from the potential noise levels of high-quality entertainment systems next door. 'We have a maximum volume for television sets, and we make sure the plumbing for showers and toilets is so done that other guests do not hear the sound of running water.' Mr Suen is responsible for providing technical guidance on a wide range of issues. This includes advising on the operation of internet protocol phone systems, fans, water pumps, kitchen equipment, laundry rooms, lifts and escalators. His special interest is energy conservation. 'I like projects which involve that. There is a payback on the initial investment and it promotes a good image in the community and with guests,' he said. Mr Suen is developing engineering standards for group hotels which incorporate principles to follow energy conservation whenever there is a modification or upgrade. 'For example, we will install air-conditioning units with water-cooled chillers, which use less electricity and produce lower carbon dioxide emissions. We are also looking into solar power for some hotels,' Mr Suen said. Also on the way are state-of-the-art room control systems to allow greater use of timer switches for lights and air-conditioning. Mr Suen is aware, however, that too much technology in the room could be confusing to some guests. 'We have to balance the benefits of hi-tech systems with not making things too complex for guests,' he said.