The "Millennium Home" uses a variety of environmental sensors, connected to a small computer, to monitor the state and activity of the "tenant". Typically they detect occupancy of the bed and other furniture, use of the lavatory, state of locks and doors, gas and water taps, movement in the rooms, and door and bed temperature. If the software detects a potentially dangerous situation, the system will first attempt to remove the danger by speaking to the tenant. If this negotiation fails, it will call a volunteer supporter by telephone.