Prefabricated Building
Content
Prefabricated building is a type of building that consists of several factory-built
components or units that are assembled on-site to complete the unit.
Prefabricated homes, often referred to as prefab homes, are specialist dwelling types
of prefabricated building, which are manufactured off-site in advance, usually in standard sections that can be easily shipped and assembled. Some current prefab home designs include architectural details inspired by postmodernism or futurist architecture.
Prefabrication is the practice of assembling components of a structure in a factory or
other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where all assembly is carried out. The term prefabrication also applies to the manufacturing of things other than structures at a fixed site. It is frequently used when fabrication of a section of a machine or any movable structure is shifted from the main manufacturing site to another location, and the section is supplied assembled and ready to fit. It is not generally used to refer to electrical or electronic components of a machine, or mechanical parts such as pumps, gearboxes and compressors which are usually supplied as separate items, but to sections of the body of the machine which in the past were fabricated with the whole machine. Prefabricated parts of the body of the machine may be called 'sub-assemblies' to distinguish them from the other components.
HISTORY
The word "Prefab" is not an industry term like modular home, manufactured home, panelized home or site-built home. The term is an amalgamation of panelized and modular building systems, and can mean either one. In today's usage the term "Prefab" is more closely related to the style of home, usually modernist, rather than to a particular method of home construction. Buildings have been built in one place and reassembled in another throughout history. Possibly the first advertised prefab house was the Manning Portable Cottage. A London carpenter, Henry Manning, constructed a house that was built in components, then shipped and assembled by British emigrants. This was published at the time (advertisement, South Australian Record, 1837) and a few still stand in Australia.[1] One such is the Friends Meeting House, Adelaide.[2][3] The peak year for the importation of portable buildings to Australia was 1853, when several hundred arrived. These have been identified as coming from Liverpool, Boston and Singapore (with Chinese instructions for re-assembly).[4] In Barbados theChattel house was a form of prefabricated building which was developed by emancipated slaves who had limited
rights to build upon land they did not own. As the buildings were moveable they were legally regarded as chattels.[5] In 1855 during the Crimean War, after Florence Nightingale wrote a letter to The Times, Isambard Kingdom Brunel was commissioned to design a prefabricated modular hospital. In five months he designed a 1,000 patient hospital, with innovations in sanitation, ventilation and a flushing toilet.[6] Fabricator William Eassie constructed the required 16 units inGloucester Docks, shipped directly to the Dardanelles. Only used from March 1856 to September 1857, it reduced the death rate from 42% to 3.5%. The world's first prefabricated, pre-cast panelled apartment blocks were pioneered in Liverpool. A process was invented by city engineer John Alexander Brodie, whose inventive genius also had him inventing the football goal net. The tram stables at Walton in Liverpool followed in 1906. The idea was not extensively adopted in Britain, however was widely adopted elsewhere, particularly in Eastern Europe. Prefabricated homes were produced during the Gold Rush in the United States, when kits were produced to enable Californian prospectors to quickly construct accommodation. Homes were available in kit form by mail order in the United States in 1908.[7] Prefabricated housing was popular during the Second World War due to the need for mass accommodation for military personnel. The United States used Quonset huts as military buildings, and in the United Kingdom prefabricated buildings used included Nissen huts and Bellman Hangars. 'Prefabs' were built after the war as a means of quickly and cheaply providing quality housing as a replacement for the housing destroyed during the Blitz. The proliferation of prefabricated housing across the country was a result of the Burt Committee and the Housing (Temporary Accommodation) Act 1944. Under the Ministry of Works Emergency Factory Made housing programme, a specification was drawn up and bid on by various private construction and manufacturing companies. After approval by the MoW, companies could bid on Council led development schemes, resulting in whole estates of prefabs constructed to provide accommodation for those made homeless by the War and ongoing slum clearance.[8] Almost 160,000 had been built in the UK by 1948 at a cost of close to £216 million. The largest single prefab estate in Britain [9] was at Belle Vale (South Liverpool), where more than 1,100 were built after World War 2. The estate was demolished in the 1960s amid much controversy as the prefabs were very popular with residents at the time. Prefabs were aimed at families, and typically had an entrance hall, two bedrooms (parents and children), a bathroom (a room with a bath) — which was a novel innovation for many Britons at that time, a separate toilet, a living room and an equipped (not fitted in the modern sense) kitchen. Construction materials included steel, aluminium, timber or asbestos, depending on the type of dwelling. The aluminium Type B2 prefab was produced as four pre-assembled sections which could
be transported by lorry anywhere in the country. The Universal House (pictured left & lounge diner right) was given to the Chiltern Open Air Museum after 40 years temporary use. The Mark 3 was manufactured by the Universal Housing Company Ltd, Rickmansworth. The United States used prefabricated housing for troops during the war and for GIs returning home. Prefab classrooms were popular with UK schools increasing their rolls during the baby boom of the 1950s and 1960s. Many buildings were designed with a five-ten year life span, but have far exceeded this, with a number surviving today. In 2002, for example, the city of Bristol still had residents living in 700 examples.[11] Many UK councils have been in the process of demolishing the last surviving examples of Second World War prefabs in order to comply with the British government's Decent Homes Standard, which came into effect in 2010. There has, however, been a recent revival in prefabricated methods of construction in order to compensate for the United Kingdom's current housing shortage.
Current uses
A house being built with prefabricated concrete panels.
The most widely used form of prefabrication in building and civil engineering is the use of prefabricated concrete and prefabricated steel sections in structures where a particular part or form is repeated many times. It can be difficult to construct the formwork required to mould concrete components on site, and delivering wet concrete to the site before it starts to set requires precise time management. Pouring concrete sections in a factory brings the advantages of being able to re-use moulds and the concrete can be mixed on the spot without having to be transported to and pumped wet on a congested construction site. Prefabricating steel sections reduces on-site cutting and welding costs as well as the associated hazards. Prefabrication techniques are used in the construction of apartment blocks, and housing developments with repeated housing units. The quality of prefabricated housing units had increased to the point that they may not be distinguishable from traditionally built units to those that live in them. The technique is also used in office blocks, warehouses and factory buildings. Prefabricated steel and glass sections are widely used for the exterior of large buildings. Detached houses, cottages, log cabin, saunas, etc. are also sold with prefabricated elements. Prefabrication of modular wall elements allows building of complex thermal insulation, window frame components, etc. on an assembly line, which tends to improve quality over on-site construction of each individual wall or frame. Wood construction in particular benefits from the improved quality. However, tradition often favors building by hand in many countries, and the image of prefab as a "cheap" method only slows its adoption. However, current practice already allows the modifying the floor plan according to the customer's requirements and selecting the surfacing material, e.g. a
personalized brick facade can be masoned even if the load-supporting elements are timber. Prefabrication saves engineering time on the construction site in civil engineering projects. This can be vital to the success of projects such as bridges andavalanche galleries, where weather conditions may only allow brief periods of construction. Prefabricated bridge elements and systems offer bridge designers and contractors significant advantages in terms of construction time, safety, environmental impact, constructibility, and cost. Prefabrication can also help minimize the impact on traffic from bridge building. Additionally, small, commonly used structures such as concrete pylons are in most cases prefabricated. Radio towers for mobile phone and other services often consist of multiple prefabricated sections. Modern lattice towers and guyed masts are also commonly assembled of prefabricated elements. Prefabrication has become widely used in the assembly of aircraft and spacecraft, with components such as wings and fuselage sections often being manufactured in different countries or states from the final assembly site. However this is sometimes for political rather than commercial reasons - e.g. Airbus
Advantages of prefabrication[edit]
1. High capacity- enabling the realization of important projects 2. Factory made products 3. Shorter construction time- less than half of conventional cast in situ construction 4. Independent of adverse weather conditions during construction 5. Continuing erection in winter time until -20 °C 6. Quality surveillance system 7. Opportunities for good architecture 8. Healthy buildings 9. Reduced energy consumption 10. Environmentally friendly way of building with optimum use of materials, recycling of waste products, less noise and dust etc. 11. Cost effective solutions 12. Reduction in construction time 13. Safety in construction 14. Increase in the quality of construction. 15. Reduction of construction waste
[1]
Disadvantages[edit]
1. Leaks can form at joints in prefabricated components. 2. Transportation costs may be higher for voluminous prefabricated sections than for the materials of which they are made, which can often be packed more efficiently. 3. Large prefabricated sections require heavy-duty cranes and precision measurement and handling to place in position. 4. Larger groups of buildings from the same type of prefabricated elements tend to look drab and monotonous. 5. Local jobs may be lost, if the work done to fabricate the components being located in a place far away from the place of construction. This means that there are less locals working on any construction project at any time, because fabrication is outsourced.
Off-site fabrication[edit]
Off-Site fabrication is a process that incorporates prefabrication and pre-assembly. The process involves the design and manufacture of units or modules, usually remote from the work site, and the installation at the site to form the permanent works at the site. In its fullest sense, off-site fabrication requires a project strategy that will change the orientation of the project process from construction to manufacture to installation. Examples of off-site fabrication are wall panels for homes, wooden truss bridge spans, airport control stations.
Prefabricated commercial buildings[edit]
Tesco modular store in Zubří, Czech Republic
McDonalds uses prefabricated structures for their buildings, and set a record of constructing a building and opening for business within 13 hours (on pre-prepared ground works).[15] In the UK, the major supermarkets have each developed a modular unit system to shop building, based on the systems developed by German cost retaillers Aldi and Netto. Assembly and Finishing
With all modules complete and shipped to the site, the foundation prepped and ready, the prefabricated modular buildings are crane set into place and connected to the foundation and each other for a solid and durable completed building. Utilities are connected and your choice of exterior finishes are added, including perfectly matched to neighboring buildings. The resulting prefabricated modular buildings are environmentally-friendly, with the all the same architectural aesthetics you would expect from conventional buildings. And with a greatly reduced time to occupancy, your business can start generating revenue sooner, and accelerate your return on investment. The ModSpace Construction Services Team can deliver environmentally-friendly prefab office buildings that meet the highest green standards, including LEED certified. Factory-control makes the best use of materials and produces less waste. Reduced energy consumption compared to on-site construction. Minimal site disruption minimizes production times and long-term footprint. Comparatively better sustainability though strategic reuse and repurposing of prefabricated office buildings.
The component nature inherent in every prefab office building allows them to be quickly and easily configured and reconfigured to meet your changing needs. Add, remove prefabricated modules at minimal expense. Reduce disruption with offsite manufacturing and quick onsite modification. Adjust and adapt floor plan to support new workflows and evolving business needs. Greater design control and therefore fewer change orders. ModSpace delivers more overall value to every prefab office project with end-to-end Design-Build capabilities. Our inhouse team of architects, engineers and construction professionals can take your modular construction project from white board to brick and mortar in less time. From your ModSpace single point of contact you’ll get more information right upfront and the expert advice you need to make well-informed, confident decisions regarding the best building and process for you.
components or units that are assembled on-site to complete the unit.
Prefabricated homes, often referred to as prefab homes, are specialist dwelling types
of prefabricated building, which are manufactured off-site in advance, usually in standard sections that can be easily shipped and assembled. Some current prefab home designs include architectural details inspired by postmodernism or futurist architecture.
Prefabrication is the practice of assembling components of a structure in a factory or
other manufacturing site, and transporting complete assemblies or sub-assemblies to the construction site where the structure is to be located. The term is used to distinguish this process from the more conventional construction practice of transporting the basic materials to the construction site where all assembly is carried out. The term prefabrication also applies to the manufacturing of things other than structures at a fixed site. It is frequently used when fabrication of a section of a machine or any movable structure is shifted from the main manufacturing site to another location, and the section is supplied assembled and ready to fit. It is not generally used to refer to electrical or electronic components of a machine, or mechanical parts such as pumps, gearboxes and compressors which are usually supplied as separate items, but to sections of the body of the machine which in the past were fabricated with the whole machine. Prefabricated parts of the body of the machine may be called 'sub-assemblies' to distinguish them from the other components.
HISTORY
The word "Prefab" is not an industry term like modular home, manufactured home, panelized home or site-built home. The term is an amalgamation of panelized and modular building systems, and can mean either one. In today's usage the term "Prefab" is more closely related to the style of home, usually modernist, rather than to a particular method of home construction. Buildings have been built in one place and reassembled in another throughout history. Possibly the first advertised prefab house was the Manning Portable Cottage. A London carpenter, Henry Manning, constructed a house that was built in components, then shipped and assembled by British emigrants. This was published at the time (advertisement, South Australian Record, 1837) and a few still stand in Australia.[1] One such is the Friends Meeting House, Adelaide.[2][3] The peak year for the importation of portable buildings to Australia was 1853, when several hundred arrived. These have been identified as coming from Liverpool, Boston and Singapore (with Chinese instructions for re-assembly).[4] In Barbados theChattel house was a form of prefabricated building which was developed by emancipated slaves who had limited
rights to build upon land they did not own. As the buildings were moveable they were legally regarded as chattels.[5] In 1855 during the Crimean War, after Florence Nightingale wrote a letter to The Times, Isambard Kingdom Brunel was commissioned to design a prefabricated modular hospital. In five months he designed a 1,000 patient hospital, with innovations in sanitation, ventilation and a flushing toilet.[6] Fabricator William Eassie constructed the required 16 units inGloucester Docks, shipped directly to the Dardanelles. Only used from March 1856 to September 1857, it reduced the death rate from 42% to 3.5%. The world's first prefabricated, pre-cast panelled apartment blocks were pioneered in Liverpool. A process was invented by city engineer John Alexander Brodie, whose inventive genius also had him inventing the football goal net. The tram stables at Walton in Liverpool followed in 1906. The idea was not extensively adopted in Britain, however was widely adopted elsewhere, particularly in Eastern Europe. Prefabricated homes were produced during the Gold Rush in the United States, when kits were produced to enable Californian prospectors to quickly construct accommodation. Homes were available in kit form by mail order in the United States in 1908.[7] Prefabricated housing was popular during the Second World War due to the need for mass accommodation for military personnel. The United States used Quonset huts as military buildings, and in the United Kingdom prefabricated buildings used included Nissen huts and Bellman Hangars. 'Prefabs' were built after the war as a means of quickly and cheaply providing quality housing as a replacement for the housing destroyed during the Blitz. The proliferation of prefabricated housing across the country was a result of the Burt Committee and the Housing (Temporary Accommodation) Act 1944. Under the Ministry of Works Emergency Factory Made housing programme, a specification was drawn up and bid on by various private construction and manufacturing companies. After approval by the MoW, companies could bid on Council led development schemes, resulting in whole estates of prefabs constructed to provide accommodation for those made homeless by the War and ongoing slum clearance.[8] Almost 160,000 had been built in the UK by 1948 at a cost of close to £216 million. The largest single prefab estate in Britain [9] was at Belle Vale (South Liverpool), where more than 1,100 were built after World War 2. The estate was demolished in the 1960s amid much controversy as the prefabs were very popular with residents at the time. Prefabs were aimed at families, and typically had an entrance hall, two bedrooms (parents and children), a bathroom (a room with a bath) — which was a novel innovation for many Britons at that time, a separate toilet, a living room and an equipped (not fitted in the modern sense) kitchen. Construction materials included steel, aluminium, timber or asbestos, depending on the type of dwelling. The aluminium Type B2 prefab was produced as four pre-assembled sections which could
be transported by lorry anywhere in the country. The Universal House (pictured left & lounge diner right) was given to the Chiltern Open Air Museum after 40 years temporary use. The Mark 3 was manufactured by the Universal Housing Company Ltd, Rickmansworth. The United States used prefabricated housing for troops during the war and for GIs returning home. Prefab classrooms were popular with UK schools increasing their rolls during the baby boom of the 1950s and 1960s. Many buildings were designed with a five-ten year life span, but have far exceeded this, with a number surviving today. In 2002, for example, the city of Bristol still had residents living in 700 examples.[11] Many UK councils have been in the process of demolishing the last surviving examples of Second World War prefabs in order to comply with the British government's Decent Homes Standard, which came into effect in 2010. There has, however, been a recent revival in prefabricated methods of construction in order to compensate for the United Kingdom's current housing shortage.
Current uses
A house being built with prefabricated concrete panels.
The most widely used form of prefabrication in building and civil engineering is the use of prefabricated concrete and prefabricated steel sections in structures where a particular part or form is repeated many times. It can be difficult to construct the formwork required to mould concrete components on site, and delivering wet concrete to the site before it starts to set requires precise time management. Pouring concrete sections in a factory brings the advantages of being able to re-use moulds and the concrete can be mixed on the spot without having to be transported to and pumped wet on a congested construction site. Prefabricating steel sections reduces on-site cutting and welding costs as well as the associated hazards. Prefabrication techniques are used in the construction of apartment blocks, and housing developments with repeated housing units. The quality of prefabricated housing units had increased to the point that they may not be distinguishable from traditionally built units to those that live in them. The technique is also used in office blocks, warehouses and factory buildings. Prefabricated steel and glass sections are widely used for the exterior of large buildings. Detached houses, cottages, log cabin, saunas, etc. are also sold with prefabricated elements. Prefabrication of modular wall elements allows building of complex thermal insulation, window frame components, etc. on an assembly line, which tends to improve quality over on-site construction of each individual wall or frame. Wood construction in particular benefits from the improved quality. However, tradition often favors building by hand in many countries, and the image of prefab as a "cheap" method only slows its adoption. However, current practice already allows the modifying the floor plan according to the customer's requirements and selecting the surfacing material, e.g. a
personalized brick facade can be masoned even if the load-supporting elements are timber. Prefabrication saves engineering time on the construction site in civil engineering projects. This can be vital to the success of projects such as bridges andavalanche galleries, where weather conditions may only allow brief periods of construction. Prefabricated bridge elements and systems offer bridge designers and contractors significant advantages in terms of construction time, safety, environmental impact, constructibility, and cost. Prefabrication can also help minimize the impact on traffic from bridge building. Additionally, small, commonly used structures such as concrete pylons are in most cases prefabricated. Radio towers for mobile phone and other services often consist of multiple prefabricated sections. Modern lattice towers and guyed masts are also commonly assembled of prefabricated elements. Prefabrication has become widely used in the assembly of aircraft and spacecraft, with components such as wings and fuselage sections often being manufactured in different countries or states from the final assembly site. However this is sometimes for political rather than commercial reasons - e.g. Airbus
Advantages of prefabrication[edit]
1. High capacity- enabling the realization of important projects 2. Factory made products 3. Shorter construction time- less than half of conventional cast in situ construction 4. Independent of adverse weather conditions during construction 5. Continuing erection in winter time until -20 °C 6. Quality surveillance system 7. Opportunities for good architecture 8. Healthy buildings 9. Reduced energy consumption 10. Environmentally friendly way of building with optimum use of materials, recycling of waste products, less noise and dust etc. 11. Cost effective solutions 12. Reduction in construction time 13. Safety in construction 14. Increase in the quality of construction. 15. Reduction of construction waste
[1]
Disadvantages[edit]
1. Leaks can form at joints in prefabricated components. 2. Transportation costs may be higher for voluminous prefabricated sections than for the materials of which they are made, which can often be packed more efficiently. 3. Large prefabricated sections require heavy-duty cranes and precision measurement and handling to place in position. 4. Larger groups of buildings from the same type of prefabricated elements tend to look drab and monotonous. 5. Local jobs may be lost, if the work done to fabricate the components being located in a place far away from the place of construction. This means that there are less locals working on any construction project at any time, because fabrication is outsourced.
Off-site fabrication[edit]
Off-Site fabrication is a process that incorporates prefabrication and pre-assembly. The process involves the design and manufacture of units or modules, usually remote from the work site, and the installation at the site to form the permanent works at the site. In its fullest sense, off-site fabrication requires a project strategy that will change the orientation of the project process from construction to manufacture to installation. Examples of off-site fabrication are wall panels for homes, wooden truss bridge spans, airport control stations.
Prefabricated commercial buildings[edit]
Tesco modular store in Zubří, Czech Republic
McDonalds uses prefabricated structures for their buildings, and set a record of constructing a building and opening for business within 13 hours (on pre-prepared ground works).[15] In the UK, the major supermarkets have each developed a modular unit system to shop building, based on the systems developed by German cost retaillers Aldi and Netto. Assembly and Finishing
With all modules complete and shipped to the site, the foundation prepped and ready, the prefabricated modular buildings are crane set into place and connected to the foundation and each other for a solid and durable completed building. Utilities are connected and your choice of exterior finishes are added, including perfectly matched to neighboring buildings. The resulting prefabricated modular buildings are environmentally-friendly, with the all the same architectural aesthetics you would expect from conventional buildings. And with a greatly reduced time to occupancy, your business can start generating revenue sooner, and accelerate your return on investment. The ModSpace Construction Services Team can deliver environmentally-friendly prefab office buildings that meet the highest green standards, including LEED certified. Factory-control makes the best use of materials and produces less waste. Reduced energy consumption compared to on-site construction. Minimal site disruption minimizes production times and long-term footprint. Comparatively better sustainability though strategic reuse and repurposing of prefabricated office buildings.
The component nature inherent in every prefab office building allows them to be quickly and easily configured and reconfigured to meet your changing needs. Add, remove prefabricated modules at minimal expense. Reduce disruption with offsite manufacturing and quick onsite modification. Adjust and adapt floor plan to support new workflows and evolving business needs. Greater design control and therefore fewer change orders. ModSpace delivers more overall value to every prefab office project with end-to-end Design-Build capabilities. Our inhouse team of architects, engineers and construction professionals can take your modular construction project from white board to brick and mortar in less time. From your ModSpace single point of contact you’ll get more information right upfront and the expert advice you need to make well-informed, confident decisions regarding the best building and process for you.
