Transcript Slide 1

All About Modular & Prefabricated
Construction…
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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.
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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.
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The following will summarize the history of the Pre-Fabricated
construction industry. Contd…
The post-World War I years brought a strong
prefabrication, but mainly in Europe. The U.S.
experiment with prefabrication, while Europe built
Europeans promoted and advanced prefabrication as
development during this time.
stimulus to
continued to
with it. The
an industrial
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.
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Prefabrication
The 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.
Modularization
Modularization 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. 5
Preassembly
A 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.
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Time to Build
Building 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 afterdelivery additions, the whole process may take a few months but is much quicker
than standard homebuilding.
Cost
Prefab 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-Green
Prefabricated 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.
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India
Ready Made Homes – Prefabricated Houses
Buying 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 Innovations
Timely 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 money
If 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
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How Prefabricated / Eco homes save your money. Contd…
stream of builders," says Sachin Sandhir, managing director, RICS South Asia, a selfregulatory 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 onsite. 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. 9
STRONG FOUNDATION
Developers 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.
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STRONG FOUNDATION. Contd…
Buildings constructed using prefab technologies have a life span of 30-50 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 Characteristics
Modularization, 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.
Advantages
The 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
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costs.
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.
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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 Impacts
There 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.
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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.
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