A prefabricated building, informally a prefab, is a building that is manufactured and constructed using prefabrication. It consists of factory-made components or units that are transported and assembled on-site to form the complete building. Various materials were combined to create a part of the installation process.[1]
History
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Friends Meeting House (a Manning cottage, 1840), North Adelaide,Buildings have been built in one place and reassembled in another throughout history. This was especially true for mobile activities, or for new settlements. Elmina Castle, the first slave fort in West Africa, was also the first European prefabricated building in Sub-saharan Africa.[2]: 93 In North America, in 1624 one of the first buildings at Cape Ann was probably partially prefabricated, and was rapidly disassembled and moved at least once. John Rollo described in 1801 earlier use of portable hospital buildings in the West Indies.[3] Possibly the first advertised prefab house was the "Manning 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.[4] One such is the Friends Meeting House, Adelaide.[5][6] 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).[7] In Barbados the Chattel 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.[8]
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 the Renkioi Hospital: a 1,000 patient hospital, with innovations in sanitation, ventilation and a flushing toilet.[9] Fabricator William Eassie constructed the required 16 units in Gloucester 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.[10]
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.[11] 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[12] 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.
Amersham Prefab (COAM)-front room showing solid-fuel firePrefabs 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 cement, 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.[13]
Amersham Prefab's Kitchen (COAM)-showing Belling cooker, Ascot wash heater and fridgeThe 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.[14] 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.[citation needed]
Prefabs and the modernist movement
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Architects are incorporating modern designs into the prefabricated houses of today. Prefab housing should no longer be compared to a mobile home in terms of appearance, but to that of a complex modernist design.[15] There has also been an increase in the use of "green" materials in the construction of these prefab houses. Consumers can easily select between different environmentally friendly finishes and wall systems. Since these homes are built in parts, it is easy for a home owner to add additional rooms or even solar panels to the roofs. Many prefab houses can be customized to the client's specific location and climate, making prefab homes much more flexible and modern than before.
There is a zeitgeist or trend in architectural circles and the spirit of the age favors the small carbon footprint of "prefab".
Efficiency
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The process of building pre-fabricated buildings has become so efficient in China that a builder in Changsha built a ten-storey building in 28 hours and 45 minutes.[16] [17]
Sustainability
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Prefabricated construction generates less carbon footprint, improves energy use and efficiency, and produces less waste, making it more sustainable and environmentally friendly, and compliant with sustainable design standards.[18][19]
Modular Architecture
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The modular architecture allows, thanks to 3D modeling, the design and construction of the modular structure outside the site where it will be installed. [20] This offers several advantages such as more sustainable design, greater cost and time savings and standardization of design. [21] This is especially important for large-scale construction projects. [22]
In communist countries
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A high-rise Plattenbau in Jena, Germany.Many eastern European countries had suffered physical damage during World War II and their economies were in a very poor state. There was a need to reconstruct cities which had been severely damaged due to the war. For example, Warsaw had been practically razed to the ground under the planned destruction of Warsaw by German forces after the 1944 Warsaw Uprising. The centre of Dresden, Germany, had been totally destroyed by the 1945 Allied bombardment. Stalingrad had been largely destroyed and only a small number of structures were left standing.
Prefabricated buildings served as an inexpensive and quick way to alleviate the massive housing shortages associated with the wartime destruction and large-scale urbanization and rural flight.
Prefabricated commercial buildings
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McDonald's 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).[23]
In the UK, the major supermarkets have each developed a modular unit system to shop building, based on the systems developed by German cost retailer Aldi and the Danish supermarket chain Netto.[24]
See also
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References
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With the explosion of e-commerce in recent years, businesses have been scrambling to add warehouse space near distribution hubs. As a result, the popularity of prefabricated steel buildings has skyrocketed as a solution. Just head to the outskirts of any major metropolitan area, and you can’t help but notice clusters of steel warehouses going up seemingly overnight.
There is a good reason for this trend: prefab steel warehouses offer many benefits. They are extremely sustainable, can be up and running in a fraction of the time of other construction types, and offer ample clear span for unmatched mobility.
With that said, there are a couple of challenges associated with steel buildings that must be strategically addressed, such as poor breathability and high thermal conductivity. Fortunately, there are many innovative insulation and ventilation products on the market that can help mitigate these concerns.
For more on the good and the bad of steel structures, keep reading for a detailed analysis of prefabricated warehouse buildings.
Advantages of Prefabricated Steel Structures
Although there are many advantages of prefab steel structures, some of the most pertinent for warehouses are elite sustainability, short construction times, and ample clear span.
Elite Sustainability
One of the greatest advantages of prefabricated steel buildings is their elite sustainability. These buildings are made from durable materials designed to last for decades with minimal maintenance or upkeep. This durability reduces the need for repairs and replacements, conserving resources and minimizing environmental impact.
Additionally, steel is one of the most recyclable materials on the planet. This recyclability allows steel buildings to be repurposed and reused, further reducing their environmental impact. In fact, steel buildings can often be disassembled and re-erected multiple times, making them the ideal choice for temporary or relocatable warehouses.
Short Construction Times
Another significant benefit of prefabricated steel buildings is their short construction times.
Steel buildings are made in a factory using precision-engineered components that are then shipped to the construction site for quick assembly. This process can take significantly less time than traditional construction methods, which require the building to be constructed on-site from scratch. According to the American Institute of Steel Construction (AISC), prefabricated steel buildings can be erected in as little as two to four weeks. This is a major advantage for businesses looking to get up and running quickly.
For example, a company that needs to expand its manufacturing capacity could build a new prefabricated steel warehouse in a fraction of the time it would take to build a traditional brick-and-mortar structure. This reduced construction time can save businesses money and help them start generating revenue sooner.
Ample Clear Span
A final advantage of prefabricated steel warehouses is their interior clear span. This means that there are no interior columns or supports, which can get in the way of operations and make it difficult to move around large equipment or materials. This clear span is made possible by the use of long-span steel beams and trusses, which can cover distances of up to 100 feet or more.
This clear span design provides several benefits, including the efficient use of storage space, as there are no columns to get in the way of storage racks or other equipment. Additionally, clear span warehouses can have uninterrupted workflow allowing equipment to move through the building without obstruction. Overall, the interior clear span of prefabricated steel warehouses is a significant advantage for businesses that require large, open spaces for their operations.
Disadvantages of Prefabricated Steel Structures
While there are many advantages of using prefabricated steel warehouses, there are a handful of items to consider to keep them functioning their best. However, with the proper techniques and tools for insulation, many of these concerns are largely alleviated.
Poor Breathability
One of the most important considerations for prefabricated steel buildings is their poor breathability. This is because steel is a non-porous material that does not allow air to pass through it easily. This can lead to a number of problems, such as increased condensation, mildew, mold growth, and rust.
Fortunately, there are a number of ways to improve steel building ventilation. These include:
Installing louvers:
Architectural louvers
allow air to flow into and out of the building, which helps to reduce condensation and improve ventilation.
Using a vapor barrier: A vapor barrier is a material that helps to prevent moisture from getting into the building. Vapor barriers are commonly on the building’s insulation to be most effective.
Installing fans: Fans can help to circulate air and remove moisture from the building.
By taking these steps, you can improve the breathability of your steel buildings and reduce the risk of problems caused by moisture.
High Thermal Conductivity
Another challenge associated with steel buildings is their high thermal conductivity. As they can quickly transfer heat, maintaining comfortable interior temperatures can be problematic in areas with extreme temperatures.
One way to mitigate this issue is to use spray foam insulation metal building solutions. This type of insulation creates a barrier between the steel and the outside temperature to protect against heat transfer.
Closed-cell spray foam is a popular insulation choice for metal buildings because it has a high R-value and is resistant to moisture, mold, and pests.
Expansion Challenges
A final argument against prefabricated steel buildings is the limited scope for future expansion. These structures are designed and constructed based on specific requirements. Expanding or modifying them later can be challenging, depending on the nature and extent of additions and the initial design of the building.
In general, pre-engineered steel buildings can only accommodate expansion if the addition is an extension of the existing building in a direction parallel to the ridge of the existing building. This means expanding the length of the structure rather than its width is generally the simplest method of expansion.
One possible approach to creating multi-story prefabricated steel structures is to use structural n decking and other load-bearing support to add additional floors. This method works great for small expansions aimed at better utilizing the vertical space of a steel structure.
Know the Pros and Cons of Prefab Steel Warehouse Buildings
Prefabricated steel buildings are one of the most popular solutions for the rampant demand for warehousing space. However, like any type of structure, prefab steel has its share of pros and cons that must be taken into consideration before breaking ground on a project. For the latest news and notes on all matters construction-related, explore the resources at Construction Marketing Association for the leading insights in the industry!