A building maintenance unit (BMU) is an automatic, remote-controlled, or mechanical device, usually suspended from the roof, which moves systematically over some surface of a structure while carrying human window washers or mechanical robots to maintain or clean the covered surfaces.
BMUs are almost always positioned over the exterior of a structure, but can also be used on interior surfaces such as large ceilings (e.g. in stadiums or train stations) or atrium walls.Building Maintenance Units are developed and customized exclusively to suit the target building for exterior access and maintenance of building façade. Mounted permanently at roof level, a BMU is the safest and most complete form of the suspended access system, providing full lateral, horizontal and vertical movement of the working platform. BMUs provide hoisting heights of up to 400m and jib outreach up to 35m, enabling safe access to even the tallest and most complex building façades. The cradles have a typical working load limit of 250kg, although additional loads can be designed into the systems to facilitate glass replacement winches for future maintenance of the building. Nowadays many companies offer a range of BMU machines that can either be fixed position or run on anchored or free-laid tracks.
Alternatively, companies provide trackless machines that can travel on a concrete surface with the aid of a guide rail, enabling the terrace area to be utilized for pedestrian access. For buildings with particularly challenging façade features, like large towers, parapets or screens, building maintenance units can incorporate a variety of bespoke functions into its machines to overcome the most demanding situations.
Taking aforementioned information into consideration, we can deduce that introduction of building maintenance unit has been the paramount invention in continuously evolving construction industry.