The Local Government (Household Charge) Act 2011 provides the legislative basis for the household charge. The definition of "building" in section 1 is relevant when considering whether a residential property is liable to the household charge. "Building" includes (a) part of a building, and (b) a structure or erection of any kind and of any materials, or any part of that structure or erection, but excludes a structure that is not permanently attached to the ground, a vessel and a vehicle (whether mobile or not). In this regard, a structure that is not permanently attached to the ground is excluded from the definition of building in the Act and is not liable to the household charge.