Approved Document G (ADG) provides guidance on the supply of water to a property, including water safety, hot water supply, sanitation and water efficiency. The guidance focuses on the supply of sanitary, drinkable water to buildings, including cold drinking water, hot water supplied to bathroom appliances including baths, showers and sinks next to toilets (or in an adjoining room) and to food preparation areas in kitchens, and any water needed for the purposes of washing. Hot water systems also require extra safety precautions when they are unvented. This 2015 edition of ADG incorporates the 2016 amendments, made to section G2: Water Efficiency, which requires the water efficiency calculator to be completed for new dwellings where a shower will not be provided.