Incandescent lighting on the parliamentary estate has been gradually replaced with lower energy lighting over the last five years, mostly during routine lamp changes. Therefore, the only cost of compliance has been the cost of the bulbs themselves which is offset by their increased life and will begin to produce savings within 500 hours of use. Due to the size and complexity of the estate, detailed records of light bulbs are not kept, but virtually no incandescent lighting remains within areas (a) the Chamber and (b) the Press Gallery. In (c), areas open to the public, the vast majority of incandescent light bulbs have been replaced over the last 12 months with halogen lamps which consume some 30 per cent. less power. On (d), the remainder of the Commons part of the estate, the only incandescent light fittings that the House has been unable to replace are those using small bayonet caps as these are not currently available. LED lighting is also currently being evaluated in several locations and low energy induction lighting is used widely such as in the Chamber and courtyards.