Improved Air Quality - A lot of the indoor air quality issues identified in new structure result from elevated humidity levels from the framing materials. Since the modular structure is substantially finished in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new structure is removed.
Modular buildings have been argued to have benefits over traditional buildings, for many different reasons.
Indoor construction. Construction is different from weather, which may boost work efficiency and averts damaged construction material.
Environmentally friendly building procedure. The controlled environment of the mill allows for more accurate construction when permitting the additional materials to be recycled in house. 
Quality. Combining traditional building techniques, quality manufacturing and third party agencies who provide arbitrary inspections, testing, and certification services for quality control, commercial modular buildings are made in strict compliance with appropriate local, state, and federal rules and regulations. On account of the requirement to transport modules to the final site, each module must be constructed to independently withstand travel and installation prerequisites. Thus the closing module-to-module meeting of independently durable components can yield a last product that is more durable than site-built structures. SIPs panels are a mild yet lasting mix of board and closed-cell polyurethane (PU) or expanded polystyrene (EPS) insulation. They also provide superior damp and cold resistance when compared to wood and other materials, and are immune to both compression shrinking and cold bridging.  Modular units may also be made to fit in with outside aesthetics of any existing construction and modular units once constructed can be virtually indistinguishable from a site-built construction.
Ability to support remote locations. Especially in countries where potential markets may be located far from industrial facilities, such as Australia, there may be much higher costs to build a site-built house in a remote area or a place experiencing a construction boom like mining towns. Modular buildings can also be beneficial in providing medical and sanitary facilities at which time, space, and money are an issue.
Modular construction may also provide an advantage in similar categories from the International Green Construction Code.
Modular construction allows for the construction and the site work to be performed simultaneously. According to some materials, this can reduce the overall completion schedule by as much as 50%. This reduces labor, financing and supervision costs. To save even more time and money, nearly all engineering and design disciplines are part of the production process. Also unique to modular structure is the capacity to simultaneously construct a building's floors, ceilings, walls, rafters, and roofs. During site-built construction, walls cannot be set until floors are set up, and ceilings and rafters can't be added until walls are erected. On the flip side, with modular construction, walls, floors, ceilings, and rafters are all built at precisely the exact same time, and then brought together in precisely the same mill to form a building. This process can allow modular building times of half that of traditional, stick-built structure.
Flexibility. An individual can continually add to your modular construction, including creating high rises. When the demands alter, modular buildings can be disassembled and the modules relocated or refurbished for their next usage reducing the requirement for raw materials and minimizing the total amount of energy expended to create a construction to meet the new demand. Essentially, the whole building could be recycled in some instances.
Low waste. With the same plans being constantly built, the producer has records of precisely what amount of substances are needed for a specified job. With the consistency, most builders can design systems which use common lengths of timber, wallboard, etc.. cut items with maximum efficacy, or have the ability to order special spans in bulk. While waste from a site-built residence may generally fill several large dumpsters, construction of a modular dwelling generates much less waste. According to the UK group WRAPup to a 90% decrease in materials can be accomplished through the use of modular construction.