For years, architects and builders have been trying to find ways to make houses more economical and comfortable to live in, as well as trying to reduce the amount of damage that houses do to the environment. 'Intelligent' housing seems to be the ideal solution. Clever use of building materials and techniques has brought us houses that are easier and cheaper to keep warm than traditional housing. Modern water systems, together with the recycling of washing water from bathrooms and kitchens, means that 'intelligent' houses use 30% less water than conventional homes.