## 7 Manufacturing, Transportation, and Installation Dimensions
[81] assessed design details for the dimensions, weight, and floor area of volumetric timber items by analyzing modular products made by eight suppliers and the modular products used in 60 modular timber projects. The length of a typical modular unit is often from 6 to 12 m [96]. The significant variation in lengths is a result of the adaptable design. Shorter lengths are derived from functional modules, such as bathrooms, separate from residential units. Modules less than 5 m long are functional or flexibly designed modules. Modules longer than 10 m are generally made for apartments. The most variable building types in module length are apartments and social housing structures, followed by hotels. This can be attributed mainly to the combination of modules tailored to fulfill the diverse demands for different types of living spaces. Shorter lengths are typically fused to generate more expansive areas. Shorter lengths are typically merged to create larger areas. For student housing, nursing homes, and hospitals, the modules do not typically use a combination design method. Nevertheless, the dimensions of the module may still vary depending on the application;for instance, certain modules may need to be configured without obstacles and with slightly increased lengths to facilitate wheelchair access [81]. Most timber volumetric modules have a width ranging from 2.50 to 4.00 m. The module's intended function has little significant influence on its width. However, the modules utilized in apartments and social housing encompass an extensive range. Hotel modules exhibited the highest degree of variability in terms of width. Transportation conditions primarily contribute to the concentration of width values between 2 and 5 m. Typically, modular rooms exceeding a width of 5 m are constructed by integrating multiple 3D modules, commonly found in offices and educational facilities requiring more space [81]. Ceiling height is also a significant architectural consideration in timber buildings. More than half of the modules that were investigated by [PERSON] et al. [81] had heights in the interval [3.00, 3.50] m. The MEP (mechanical, electrical, and plumbing) system area is positioned either above the ceiling or below the floor of the room module, depending on the construction technique. [PERSON] and [PERSON] [97] proposed a height range of 2.40 to 2.70 m from floor to ceiling (including finishes) for residential purposes, irrespective of the country or region. The Tall Buildings Statement of London [98] recommends a ceiling height of 3.20 m, reflecting the need to accommodate facilities and services. According to [PERSON] et al. [48], measurements considering the distance between the floor of one level and the floor of the next range from 2.81 to 3.30 m, with an average of 3.00 m. Only two out of the thirteen buildings they analyzed exceeded the 3.20 m suggested by the Tall Buildings Statement of London [98]. The largest floor area of 50 m\({}^{2}\) is used for hotels and residential buildings. The standard floor space for volumetric modules ranges from 15 to 25 m\({}^{2}\)[81]. Timber modules can be divided into functional and room modules based on the difference in mass. Functional modules encompass various facilities, such as luxatories (including saunas) and equipment rooms. The mass of timber room modules falls into the range of 5 to 15 t, and the mass of an equipment room is less than 25 t [81]. The dimensions of a standard modular unit are constrained by transportation and lifting requirements. In addition, the maximum lifting capacity of most tower cranes used in building projects is around 20 tons, and the cost of a tower crane with a lifting limit of over 20 tons might increase by up to 60%. Hence, transportation and lifting requirements serve as the primary limitations in establishing both the module size and hoist weight. In the case of high-rise buildings, the modules at the base experience substantial vertical loads.