Businesses in the other building completion category carry out finishing work that helps make a building ready for use, but does not fall neatly within a single specialist trade. Work may be undertaken on new buildings, extensions and refurbished properties, and can include making good surfaces, completing details left after major construction, fitting finishing elements and carrying out minor repairs. The precise range depends on the contractor's skills and the type of building. Customers may also find services such as building snagging, sealing gaps, installing or adjusting fixtures and fittings, cleaning or treating building exteriors, and restoring or finishing surfaces. Some contractors coordinate several small completion tasks, while others focus on a particular process or material. Structural alterations, electrical work, plumbing and other regulated or specialist tasks may need to be handled by appropriately qualified tradespeople.