Modular or volumetric construction uses pre-engineered modular units, which are transported from the factory to the site, and are installed as fitted out and serviced ‘building blocks’. The modular units may be room-sized or parts of larger spaces which are combined together to form complete buildings, such as residential buildings and hotels. Light steel framing is an integral part of modular construction, as it is strong, durable, light in weight and dimensionally stable. It is used as the internal framework of the units to which a variety of cladding and finishes may be attached. The framework is sufficiently stiff and robust that it protects the internal finishes against damage during transportation and lifting into place.
The application of modular construction is most economic in the repetitive production of a large number of similar, often room-sized units where the economy of scale can be realised. Critical portions and service installations are made ‘off the critical path’ and where quality can be assured. Modular toilets, bathrooms, lifts, service plants etc. can also be introduced into otherwise conventional buildings.
The sizes of modular units are dictated by the economics of Transportation. Units can also be provided with open sides to create larger internal spaces. All modular buildings are designed to be ‘permanent’ in terms of compliance with Building Regulations, although they are by definition relocatable and reusable. Both speed of construction and improved quality create business-related benefits to the client by early return on capital invested, or less ‘down-time’ in use of existing facilities in building extensions. ‘Quality’ implies fewer callbacks and in- service problems. Increasingly, construction is seen as a dirty and disruptive operation, which affects neighbouring properties and the road network. Modular construction reduces the time on site, is much less noisy and produces negligible waste. Furthermore, deliveries to site can be timed to suit the local conditions.
Modular components are typically constructed indoors on assembly lines. Independent building inspectors are on site to supervise the construction and ensure that the our company adheres to all building codes during assembly. Modules' construction may take as little as ten days but more often one to three months. Completed modules are transported to the building site and assembled by a crane. Placement of the modules may take from several hours to several days. Once assembled, modular buildings are essentially indistinguishable from typical site-built structures. While mobile manufactured buildings often decrease in value over time, a well-built modular building should retain value similarly to site-built structures.
The entire process of modular construction must place great importance on the design stage. This is where practices such as Design for Manufacture and Assembly (DfMA) are used to ensure that assembly tolerances are controlled throughout manufacture and assembly on site. It is vital that there is enough allowance in the design to allow the assembly to take up any "slack" or miss-alignment of components. The use of advanced CAD systems and manufacturing control systems are important for modular construction to be successful. This is quite unlike on-site construction where the tradesman can often make the part to suit any particular installation.
Typically, our modular dwellings are built to local, state or council code, resulting in dwellings from a given manufacturing facility having differing construction standards depending on the final destination of the modules. For example, homes built for final assembly in a hurricane-prone area may include additional bracing to meet local building codes.
Building strength Modular homes are designed to be stronger than traditional homes by, for example, replacing nails with screws, adding glue to joints, etc. This is to help the modules maintain their structural integrity as they are transported on trucks to the construction site.
For eg.:-When FEMA studied the destruction wrought by Hurricane Andrew in Dade County Florida, they concluded that modular and masonry homes fared best compared to other construction due to fix foundation.
Modular buildings can be assembled on top of multiple foundation surfaces, such as a crawl space, stilts (for areas that are prone to flooding), full basements or standard slab at grade. They can also be built to multi-story heights. Motels and other multi-family structures have been built using modular construction techniques. The height to which a modular structure can be built depends on jurisdiction, but a number of countries, especially in Asia, allow them to be built to 24 floors or more. Exterior wall surfaces can be finalized in the plant production process or in the case of brick/stone veneers, field applications may be the builders' choice. Roof systems also can be applied in the field after the basic installation is completed.
Because construction of modular buildings can occur simultaneously with the site and foundation work, projects can be completed 30% to 50% sooner than traditional construction.
60 - 90% of the construction is completed inside a factory, which mitigates the risk of weather delays. Buildings are occupied sooner, creating a faster return on investment.
Modular buildings are built to meet or exceed the same building codes and standards as site- built structures, and the same architect-specified materials used in conventionally constructed buildings are used in modular construction projects – wood, concrete and steel.
The indoor construction environment reduces the risks of accidents and related liabilities for workers.
PMC relies on advanced BIM for visualization to assess the energy performance and identify the most cost-effective efficiency measures. PMC is ideal for the use of this technology where the construction process is already a collaboration of systems, materials and people—much like the software itself.
Modular units may be designed to fit in with external aesthetics of any existing building and modular units, once assembled, are virtually indistinguishable from their site-built counterparts.
Modular buildings can be disassembled and the modules relocated or refurbished for new use, reducing the demand for raw materials and minimizing the amount of energy expended to create a building to meet the new need.
When building in a factory, waste is eliminated by recycling materials, controlling inventory and protecting building materials.
Because the modular structure is substantially completed in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new construction is eliminated.