2 History of Modular & Prefabrication Construction The history of modularization, prefabrication, and preassembly contains a variety of trends. It consists of a series of upswings and downswings centered on wars, economic shifts and housing booms.The following will summarize the history of the Pre-Fabricated construction industry.Several instances in history can be viewed as early forms of prework. A few significant instances stand out. Documented examples of prefabrication can be found as far back as the 1600’s. As early as 1624, the English brought with them to Cape Ann a panelized house of wood for use by the fishing fleet. This house was subsequently disassembled, moved, and reassembled several times.Another example of prefabrication by Europeans can be seen in the 1850’s. Britain’s Great Exhibition of 1851 featured a building called the Crystal Palace. Joseph Paxton designed and oversaw the construction of this huge 1848-ft. by 454-ft.structure. Paxton’s design, sketched out in less than two weeks, consisted of light and cheap materials: iron, wood, and glass. The dimensions of the building were based on 24-ft. intervals because this was the maximum size of a sheet of glass that could be manufactured at a reasonable cost. The construction period lasted only a few months and consisted of assembling the prefabricated components. After the Exhibition, the palace was taken apart, piece by piece, and moved to Sydenham. Broken glass was even remelted, providing some of the replacements.
3 The following will summarize the history of the Pre-Fabricated construction industry. Contd… There are numerous other examples of what could be considered very early uses of prefabrication or modularization, such as Stonehenge. Encyclopedia Britannica dates the modern form of prefabrication back to 1905.Modern prefabrication in the United States can be said to have started over 100 years ago, when the wooden frame house was developed. These houses introduced into home construction the first elements of prescheduled procedures upon which modern mass production are based.For the U.S., prework originated in the housing industry. This can also be seen in the very early 1900’s with housing catalogs. Both Sears and Aladdin provided a ready-made “house-in-a-box” that could be purchased and delivered as an actual “mail order house.” After it arrived, instructions were included for the purchaser to construct the house himself using standard tools. Every piece and component that would be necessary was provided and ready to be put in place. This technique is referred to as “scientific home building” by the catalogs.
4 Know about Prefabricated Houses before you buy… The following will summarize the history of the Pre-Fabricated construction industry. Contd…The post-World War I years brought a strong stimulus to prefabrication, but mainly in Europe. The U.S. continued to experiment with prefabrication, while Europe built with it. The Europeans promoted and advanced prefabrication as an industrial development during this time.Know about Prefabricated Houses before you buy…Prefabrication, pre-assembly, and modularization are well-established strategies for construction. They have the potential to reduce project duration, improve productivity, reduce labor costs, and streamline the supply chain.Prefabrication and modularization have been steadily advancing in the housing sector of construction since its early days of inception.
5 PrefabricationThe word “Prefab” does not describe just one exact style of home building. Prefab is term that includes older-style kit homes, panelized and modular building systems. Prefab houses are quicker to build, but their quality is not significantly lower, in today’s modern era we get high quality Prefabricates houses manufactured by worlds largest companies and they are more sturdy then the conventional houses, also most importantly come with a “Warranty”, which in turn is “Value to your Hard earned money”.Prefabrication normally involves one skill or trade, such as electrical, piping, or rebar. Prefabrication can be defined as “a manufacturing process, generally taking place at a specialized facility, in which various materials are joined to form a component part of a final installation”. These prefabricated components often only involve the work of a single craft. Any component that is manufactured offsite and is not a complete system can be considered to be prefabricated.ModularizationModularization is generally referred to as the preconstruction of a complete system away from the job site that is then transported to the site. The modules are large in size and possibly may need to be broken down into several smaller pieces for transport. Usually more than one trade is involved in the assembly of a module.
6 SIPs (Structural insulated panels) PreassemblyA common definition for preassembly is “a process by which various materials, prefabricated components, and/or equipment are joined together at a remote location for subsequent installation as a unit”. The preassembly may be completed at the job site in a location other than the place of final installation. The preassembly process can involve adapting sequential activities into ones that are parallel. A preassembly often contains only portions of systems, and work from a variety of crafts is typically necessary. Preassembly is generally considered to be a combination of prefabrication and modularization. It may use fabricated components made offsite and then assembled near the site. These units can then be installed at the site, similar to modules.SIPs (Structural insulated panels)Structural insulated panels (SIPs) are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are typically made by sandwiching a core of rigid foam plastic insulation between two structural skins of oriented strand board (OSB). Other skin material can be used for specific purposes. SIPs are manufactured under factory controlled conditions and can be custom designed for each home. The result is a building system that is extremely strong, energy efficient and cost effective. Building with SIPs will save you time, money and labor.
7 Time to BuildBuilding a house at a factory can be done in as little as a few days. Delivering the house will take time to plan out and can cause some delay. Assembling the house will also only take a few days. Due to factory conditions, inspections and some after-delivery additions, the whole process may take a few months but is much quicker than standard homebuilding.CostPrefab homes are close in cost or slightly higher to other standard homes built on site, but in general they are somewhat cheaper as compared to conventional houses because of their Go-Green concepts, you may initially pay more but in the long run you save on your heavy bills of maintenance over many things of utility in your house.Go-GreenPrefabricated homes are more environmentally friendly because they are mostly constructed inside a controlled factory setting, where it is much easier to build to precise specifications, with the exact materials, keeping waste to a minimum. Some architects of prefabricated homes now specifically use materials made from recycled products. An example of such a material is insulation derived from discarded denim.
8 Ready Made Homes – Prefabricated Houses IndiaReady Made Homes – Prefabricated HousesBuying a ready-made modular kitchen or bathroom is now par for the course for a number of Indians. But what if you could go to a store, buy a house and get it assembled on your plot?With pre-fabricated or prefab technology becoming popular, this might become a reality in a few years.Realty InnovationsTimely delivery of properties is important for both builders and buyers. From the buyer’s point of view, early possession of an apartment means early freedom from rent payments.How Prefabricated / Eco homes save your moneyIf the buyer is an investor, he can start earning rental incoming early. Also, once its project is complete, the builder can invest the capital in new projects and earn more profits."Given the requirement of 26.5 million affordable housing units in India and project execution challenges and shortage of human resources, the traditional 'brick and mortar' construction is giving way to prefab structures and materials. Prefab technologies can be used to build homes quickly and cost-effectively, especially as traditional construction costs continue to rise. As the cost of borrowing is steep and developers are facing a liquidity crunch, time means money. Modular construction is faster and adds to the revenue
9 How Prefabricated / Eco homes save your money. Contd… stream of builders," says Sachin Sandhir, managing director, RICS South Asia, a self-regulatory body of real estate professionals.“Prefab homes use latest technology and minimize defects through stringent quality checks.”“Quote by SACHIN SANDHIR, Managing Director, RICS South Asia.Prefab technology involves use of factory-manufactured components in building. Some commonly used prefab materials include steel frames for structures, panels made of wood, cement, gypsum and other materials for floors, walls and ceilings, factory-made doors, windows and ventilators.In large construction projects, various modules of the structure are cast off-site in factories and then assembled on the site.In the process, prefab materials such as wall and terrace blocks, wall panels, steel frames and plaster boards are used along with innovations such as the dry-wall technique. In prefab technology, the entire building can be designed using architecture software. Later components such as steel frames, wall & ceiling panels and floor tiles can be custom made.The components are then brought to the construction site and the structure is assembled on-site. Houses using steel frames for structure can have multiple stories without pillars, beams and concrete. Alternatively, the main structure and outer walls can be constructed using the conventional techniques and inside partitioning and interiors done with prefab materials.
10 STRONG FOUNDATIONDevelopers have already started using prefab materials in buildings.“We are using pre-fabricated concrete panels as shear walls and roof slabs, which are assembled like Lego blocks. Apart from prefab panels, complete kitchen and bathroom units are also being assembled as separate units with complete electrical and plumbing systems. These kitchens and bathroom ‘pods’ are then fit into place,” says Executive Director of a New Delhi based Construction Company.Prefab construction reduces construction time and improves the quality of the building. Though prefab materials are 15-20% expensive than the traditional ones, higher efficiency and less wastage and labour costs can bring down the overall cost substantially for large buildings. They also eliminate the need for auxiliary activities such as plastering, electrical wiring and plumbing as these are done at the casting stage itself.The use of prefab techniques can also result in better cost efficiencies over the life span of the buildings. By opting for pre-fabricated building solutions over traditionally constructed homes, one can achieve savings both in the short term & over the life of the structure. Usually, pre-engineered or pre-fabricated houses show better performance, as factory- or assembly-line- produced homes are manufactured to stricter norms. Such building solutions use cutting edge technology and reduce the number of manufacturing defects given the strong quality checks that can be put in place.
11 STRONG FOUNDATION. Contd… Buildings constructed using prefab technologies have a life span of years, equivalent to the lifespan of structures using conventional methods.Using prefab materials in buildings also gives flexibility in terms of expansion and modification. Most of these buildings are modular with independent blocks that can be added or removed. Computer-aided design & certain materials produce structures which can be easily assembled and dismantled a number of times without damage. Also, additional changes in the structure can be made on-site in short span.Prework Method CharacteristicsModularization, prefabrication, and preassembly each has advantages and disadvantages. The extent to which they are used is a function of many factors that are unique to each project and jobsite.AdvantagesThe overall cost for a project that uses offsite work can be less than a traditionally stick-built undertaking in certain instances. This can be caused by a variety of factors. The local labor for onsite work may be very expensive or inefficient. Severe onsite conditions and weather problems can lead to costly delays that can be avoided through prework. Also, onsite interference and worker congestion can be avoided, increasing productivity and lowering costs.
12 Advantages. Contd…The onsite construction duration can be substantially shortened through the use of prework. More work for a project can be completed before going to the site so that the construction schedule is decreased. This can be an important factor for owners with compressed schedules.Overall project safety can be improved through the use of offsite work. The risk to owners and contractors of worker accidents and lost time is reduced with construction work that is transferred away from the jobsite. Onsite work can be less safe due to ever changing conditions, elevated work, and congestion. Manufacturing and offsite work reduce all of these factors to provide a safe and productive environment. Quality can also be improved through the use of offsite work. Controlled factory and production conditions and repetitive procedures and activities, along with automated machinery can lead to a higher level of quality than can be attained onsite.A positive side-effect of using prework is potentially decreased environmental impact of the project. This is partly due to reduced jobsite construction duration and a decrease in field labor requirements. Labor availability can be an advantage as well for offsite work.
13 Disadvantages and Impacts Advantages. Contd…There is generally a constant, employed workforce for offsite prefab plants. Weather is less of a factor for prework, providing an additional advantage over stick-build site work. The prefabrication and modularization shops take advantage of controlled environments that are not affected by harsh weather. Work is not interrupted and productivity can remain at a high level. Simultaneous production, or parallel work, can be exploited with the use of prework. Instead of performing tasks in a strictly linear sequence onsite, construction activities can be broken up and completed simultaneously at multiple locations. This process shortens the construction duration and reduces onsite congestion by dispersing the workers.Disadvantages and ImpactsThere are also several impacts to the use of prework. Some of the impacts may be beneficial in the long run, such as pre-project planning. Transportation costs can be a disadvantage to offsite work. This is especially true for large modularized sections that must be transported over a long distance. Size constraints and limitations exist, based on the method of travel, which directly leads into cost and schedule considerations.
14 Disadvantages and Impacts. Contd… There is a need for increased engineering effort upfront. This means that design work and extensive planning must be completed before prework can begin. Interference analysis is required and lift planning, for example, must be completed well in advance. In practice, these activities can lead to a better performing project. While there may be a sense of inflexibility associated with prework, because it is much more difficult to make modifications after a project has begun, it may in fact lead to better scope control.******