28381106-Chapter-2-IBS

CHAPTER 2

INDUSTRIALISED BUILDING SYSTEM

2.0 INTRODUCTION

This chapter will explain in details and provide the literature review of Industrialised

Building System (IBS). This chapter will also cover the literature review of building

systems itself. Generally, the contents of this chapter are; definitions, history, types,

benefits, classification, characteristic, advantages, disadvantages, Open Building

System, Modular Coordination, implementation of IBS in Malaysia as well as its

barriers, IBS scoring system and IBS Roadmap 2003-2010.

2.1 DEFINITIONS OF INDUSTRIALISED BUILDING SYSTEM

Until the present time there has been no single commonly-approved definition of IBS.

IBS can be different things to different industry players. However, there are several

definitions from difference resources that reflected the concept of IBS which widely

accepted by the construction industry.

For the purpose of this research, IBS is best defined according to CIDB Malaysia

(2001). CIDB Malaysia (2001) defines IBS as a construction technique in which

components are manufactured in a controlled environment (on or off-site), transported,

positioned and assembled into a structure with minimal additional site works. As such,

components that are being pre-fabricated in a controlled environment on-site are also

considered as IBS. While there are numerous descriptions of the Industrialised Building

Systems (IBS) concept by local researchers, all of the definitions stressed on pre-

fabrication and mass production.

According to Warswaski (1999), the industrialised building system (IBS) can be defined

in which all building such as wall, slab, beam, column and staircase are mass produced

either in factory or at site factory under strict quality control and minimal wet site

activities. Industrialisation process is an investment in equipment, facilities and

technology with the objective of maximising production output, minimizing labour

resource and improving quality while a building system is defined as a set 10 of

interconnected element that joint together to enable the designated performance of a

building.

In another definition by Esa and Nuruddin (1998) claimed that IBS is a continuum

beginning from utilizing craftsman for every aspect of construction to a system that

make use of manufacturing production in order to minimise resource wastage and

enhance value for end users. Another definition of IBS in the construction industry

includes the industrialized process by which components of building are conceived,

planning, fabricated, transported and erected on site (Thanoon & others (2), 2003).

Meanwhile, elaboration of IBS was also clarified by Junid (1986) whereby the IBS in

construction industry includes the industrialised process which the components are

conceived, planned, fabricated, transported and erected on site. The system balance

combination between the software and hardware components. The software elements

include system design which study the requirements of end user, market analysis,

development of standardise components, establishment of manufacturing and assembly

layout and process, allocation of resources and materials and definition of a building

designer framework. The software elements provide a prerequisite to create the

conducive environment for IBS to expand.

In early literature, Dietz (1971) defined IBS as a total integration of all subsystem and

components into overall process fully utilizing industrialised production, transportation

and assembly techniques.

Parid (1997) defined IBS as a system which use industrialised production technique

either in the production of component or assembly of the building or both.. According

to Trikha (1999), industrialised building system is a building system in which all

building components such as wall, floor, slab, beam and staircase are mass produced

either in factory or at site under strict quality control and minimal on site activities.

Lessing et al (2005) explained IBS as an integrated manufacturing and construction

process with well planned organization for efficient management, preparation and

control over resources used, activities and results supported by the used of highly

developed components.

Rahman et al (2006) defined IBS as a construction system that is built using pre-

fabricated components. The manufacturing of the components is systematically done

using machine, formworks and other forms of mechanical equipment. The components

are manufactured offsite and once completed will be delivered to construction sites for

assembly and erection.

IBS also can be defined as construction systems in which components are manufactured

in a factory, on or off site, positioned and assembled into a structure with minimal

additional site works (IBS Survey, 2003). The word ‘building’ in the IBS term relates to

‘constructing’ and therefore covers all type of structures (not only for buildings

construction). It is a products, system and techniques used in making construction less

labor-oriented, faster than and as well as quality controlled.

Furthermore, the word ‘prefabrication’ also frequent used while define Industrialised

Building System which carried the means “the manufacture of component parts of a

building and its services prior to their assembly on site” (Wilson, Smith and Deal,

1998). Prefabricated techniques can be used in a wide range of application during the

construction process, from the simple prefabricated site hut, up to volumetric units that

are designed for integrating into the building structure.

Beside, the term “Industrialised Building System” can be separate to several phases

which carried its own definition:

(i) ‘Industrialised system’ means to build on-site with elements or components

produced by series in plants. These components are things like floors, walls, column,

beams, and roofs. They are then assembled and erected on the site properly joined to

form the final units. (CIDB, 2001)

(ii) ‘Industrialised building’ is the term given to building technology where modern

systematized methods of design, production planning and control as well as mechanized

and automated manufacture are applied (Ingemar Lofgren and Kent Gylltoft, 2000).

(iii) ‘Building system’ means a building system includes design rules and a product

system whose parts have compatible interfaces, thus permitting the use of several

alternative components and assemblies. The compatibility of the components and

assemblies is assured by means of a dimensional and tolerance system as well as

connection and joints (Ingemar Lofgren and Kent Gylltoft, 2000).

Perhaps the most comprehensive definition of IBS is IBS in the construction industry

includes the industrialised process by which components of a building are manufactured

transported and erected on site and managed to produce lean construction. The system

includes a balanced combination between the software and hardware components. The

hardware elements are categorised into three major groups which includes frame

system, panel system, and box or modules system. Meanwhile the software elements

include system design, market analysis, development of standardised components,

establishment of manufacturing and assembly layout and process, allocation of

resources and materials and definition of a building designer conceptual framework.

2.2 CLASSIFICATION OF BUILDING SYSTEM

There are four types of building system in Malaysia according to Badir- Razali

building system classification. (Badir et al. 1998). The building systems are namely

conventional column-beam-slab frame system with timber and plywood as formwork,

cast in-situ system with steel or aluminium as formwork, prefabricated system and the

composite building system is shown in Figure 2.0. Each building system is represented

by its construction technology, functional and geometrical configuration. There from

the four systems, excluding conventional building system, are identified as

industrialised building system.

Figure 2.0: Types of building system in Malaysia (Badir et al. 1998)

2.2.1 Conventional Construction Method

Badir et al, (1998) stated that conventional building method is defined as

components of the building that are prefabricated on site through the processes of

timber or plywood formwork installation, steel reinforcement, and cast in-situ.

Conventional buildings are mostly built of reinforced concrete frames. The traditional

Building System

ConventionalColumn-Beam–Slab FrameSystem withTimber andPlywood asFormwork

Cast in-situ System with

Steel or Aluminium

as Formwork

PrefabricatedSystem

CompositeBuilding

construction method uses wooden formwork. It is much more costly for construction

which includes labour, raw material, transportation and low speed of construction time.

2.2.2 Cast-In-Situ Construction Method

According to Badir et al, (1998), this system is suitable for a country where

unskilled labour is limited. There is no heavy machinery or high technology involved.

The system is technically applicable to almost all types of building. Formwork is used

as a mould where wet concrete is poured into a temporary system. The temporary

system also acts as a temporary support for the structures.

The objective of an in-situ method is to eliminate and reduce the traditional site-

based trades like traditional timber formwork, brickwork, plastering and to reduce

labour content. A carefully planned in-situ work can maximise the productivity, speed

and accuracy of pre-fabricated construction. Cast in-situ method uses lightweight pre-

fabricated formwork made of steel/fiberglass/aluminium that is easily erected and

dismantled. The steel reinforcement is placed within the formwork as they are being

erected and concrete is poured into the mould. When the concrete is set according to the

required strength, the moulds are dismantled. The workers can be easily trained to erect

the moulds and set the steel reinforcement. Its advantages over the traditional

construction method include, low skill requirement, speedy construction, low

maintenance, durable structure and less cost.

2.2.3 Composite Construction Method

Badir et al, (1998) stated that the objectives of composite construction method

(partially pre-fabricated) are to improve quality, reduce cost, and shorten construction

time. The concept of partial industrialised system is derived from the composite nature

of full industrialisation, and is used to describe a manufacturing or production strategy

that selectively uses some industrialising aspects, while avoiding or postponing the use

of others. The pre-fabricated construction method is combined in such a manner that the

features applied could be prominently demonstrated, especially composing various

works such as temporary facilities, building frames, building finishes, and equipments.

2.2.4 Fully Pre-fabricated Construction Method

In this method of construction, all elements that can be standardised are pre

fabricated in the factory. Normally, this method would involve the assembly of precast

elements such as floor slabs, in-filled walls, bathrooms, staircases, etc. into place for

incorporation into the main units, columns and beams. This method of construction has

reduced the amount of site labour involved in building operations and increased the

productivity of the industry. Precast building systems can reduce the duration of a

project if certain conditions are met. The last three construction methods are considered

as non conventional construction methods. These types of construction are specifically

aimed at increasing productivity and quality of work through the use of better

construction machinery, equipment, technology and materials.

2.3 CLASSIFICATION OF INDUSTRIALISED BUILDING SYSTEM

According to Badir et al. (1998), IBS can be classified according to several aspects;

i) Classification according to structural system

ii) Classification according to material

iii) Classification according to relative weight of components

2.3.1 Classification according to structural system

According to Abraham Warszawski (1999), IBS system can be classified according

structural systematic aspects. IBS can be classifies into three categories as:

Linear system or frames (beams and column)

Panel System

Rectangular or Boxes system or Three dimensional system

Figure 2.1, Figure 2.2 and Figure 2.3 shows the concept of the system as classified

above.

2.3.1.1 Frame system

Frame system is system that use column and beam as the main structure member

where columns and beams support all the building weight. The walls need to be light

and easy to install and concrete panels are introduces as flooring element (Badir et al.,

1998).

2.3.1.2 Panel system

In panel system, loads are distributed through large floor and wall panels where

walls support the building weight. This system is applicable to buildings which

functionally require a large number of walls such as apartment house, hotel and

hospital. This system is not applicable to buildings with large spans or many stories

(Badir et al., 1998).

2.3.1.3 Box system

The box systems include those systems that employ three-dimensional modules

or boxes for fabrication of habitable units that are capable of withstanding load from

various directions due to their internal stability (Badir et al., 1998).

2.3.2 Classification according to material

i) Timber

Figure 2.1: Frame System Figure 2.2: Panel System Figure 2.3: Box System

There are two types of prefabrication of timber which is ready-cut plus shop fabrication

of joints (column and beam) and structural panels where there are only walls and floors

without column and beam.

ii) Brick and block work

Laying of brick or block are carried out in a mass at factory and transported to site or on

site beside the building under construction in the form of panel and then erected.

iii) Steel

Steel construction essentially contains factors of prefabrication which is one of the

criteria of IBS. Elements are jointed by welding, riveting or bolting on site. The large

proportion of the strength to the weight allows a long-span or high-rise building.

iv) Reinforced concrete

Reinforced concrete has high degree of availability, low material cost, durability, and

fire resistance. There are two basic directions in development of reinforced concrete

IBS component which is panelised components such as walls and floors and precast

frame members such as columns and beams. Jointing at site is the key issue of this

system.

2.3.3 Classification according to relative weight of components

The IBS components can be classified according to their relative weight as in Table 2.4.

Majzub (1977) mentioned that the relative weight of components should be used as a

basis for building classification due to the factor of weight has significant impact on the

transportability of components and has influence on the production method of the

components and their erection method on site.

No General System

System Production Material

1 Frame Light weight frame Wood, light gage metals

System Medium light weight frame Metal, reinforced plastics, laminated wood

Heavy weight frame Heavy steel, concrete

2 Panel system

Light and medium weight panel

Wood frame, metal frame and composite material

Heavy weight panel(factory produced)

Heavy weight panel (tilt up-produced on site)

3 Box system (modules)

Medium weight box (mobile)

Wood frame, light gage metal, composite

Medium weight box (sectional)

Heavy weight box (factory produced)

Heavy box (tunnel produced on site)

Table 2.4: Building system classification according to relative weight of component. (Majzub, 1977)

According to CIDB (2001), the Industrialised Building System is a construction

process that utilizes techniques, products, components, or building systems which

involve prefabricated components and on site installation. Base on the structural aspects

of the system, IBS can be identified into five major groups:

i. Precast Concrete Framing, Panel and Box Systems

Precast concrete elements are the most common IBS type. There are precast concrete

columns, beams, slabs, walls, lightweight precast concrete, and permanent concrete

formworks. Beside, it is also consist of 3D components such as balconies, staircases,

toilets, lift chamber, refuse chambers and etc.

ii. Steel Formwork Systems

Concrete

Concrete

Wood frame, light gagemetal, composite

Concrete

Concrete

They generally involve site casting, and therefore subjected to structural quality control.

So, it is considered as the “low level” or the “least prefabrication” IBS types. However,

this system does offer high quality finishes and fast construction with less site labor and

material requirement. These include tunnel forms, tilt-up systems, beam and columns

moulding forms and permanent steel formworks like metal decks.

iii. Steel Framing Systems

This system commonly used with precast concrete slabs, steel columns and beams have

always been the popular choice and used extensively in the fast-track construction of

skyscrapers. Recent development in this type of IBS includes the increased usage of

light steel trusses. It is consisting of cost-effective profiled cold-formed channels and

steel portal frame systems as alternatives to the heavier traditional hot-rolled sections.

iv. Timber Framing Systems

The products are including timber building frame and timber roof truss. While timber

roof truss systems are more popular, timber building frame systems also have its own

niche market where it is offering interesting designs from simple dwelling units to

buildings requiring high aesthetical values such as chalets for resorts.

v. Blockwork Systems

By using this effective alternative system, the tedious and time-consuming traditional

brick laying tasks are greatly simplified. The construction method of using conventional

bricks has been revolutionized by the development and usage of interlocking concrete

masonry units (CMU) and lightweight concrete blocks.

2.4 CHARACTERISTICS OF INDUSTRIALISED BUILDING SYSTEM

The main features of an industrialised building system are as follows: (Warszawski,

1999).

i. As many of the building elements are prefabricated offsite, at a central facility,

where specialized equipment and organization can be established for this

purpose.

ii. The various building works are incorporated into large prefabricated assemblies

with minimum erection, jointing and finishing work onsite.

iii. Materials and component handling onsite is extensively mechanized; in concrete

work, large standard steel forms, ready-mixed concrete, and concrete pumps are

used.

iv. Design, production, and erection onsite are strongly interrelated. They must be

viewed therefore as parts of an integrated process which has to be planned and

coordinated accordingly.

Industrialised Building System has its own characteristics which are differ itself from

conventional method. There characteristics of Industrialized Building System are

(CIDB, 2001):

i. Industrial production of components though prefabrication; or highly

mechanized in-situ processes

ii. Reduced labor during prefabrication of components and site works.

iii. Modern design and manufacturing methods which has the involvement of

Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM).

iv. Systematic Quality Control such as ISO 9000 principles.

v. Open Building concept where it is permitting hybrid applications, adaptable to

standardization and Modular Coordination (MC).

2.6 ADVANTAGES OF INDUSTRIALISED BUILDING SYSTEM (IBS)

According to CIDB (2003), compares to conventional construction method, the

industrialised building system has the following advantages:

i. Less construction time

IBS requires less construction time because casting of precast element at factory

and foundation work at site can occur simultaneously and the work at site is only

the erection of IBS components. This leads to earlier occupation of the building.

ii. Cost savings

The formwork of IBS components are made of steel, aluminium or other materials

that allows for repetitive use and this leads to considerable cost savings.

iii. Saving in labour

When the IBS components are produced in factory, higher degree of utilisation of

machine is permitted and the use of labour will be reduced and lead to saving in

labour cost.

iv. Less labour at site

The use of IBS will reduce the construction process at site and consequently reduce

the number of labour required at site.

v. Optimised use of material

The utilisation of machine during the production of IBS components lead to

higher degree of precision and accuracy in the production and consequently

reduce material wastage.

vi. Higher quality and better finishes

An IBS component have higher quality and better finishes due to the careful

selection of materials, use of advanced technology, better and strict quality

assurance control since production in factory is under sheltered environment.

vii. Construction operation less affected by weather

Faster project completion due to rapid all weather construction. The effects of

weather on construction operation are less due to the fabrication of IBS

components is done in factory while at site is only erection of the components.

viii. Flexibility

IBS provides flexibility in the design of precast element so that different systems

may produce their own unique prefabrication construction methods.

ix. Increase site safety and neatness

Utilisation of IBS components leads to less construction process especially wet

work at site. This will lead to the neater site condition and increase safety.

x. Environmental friendly

The use of IBS will decrease the using of timber formwork on construction

projects.

2.7 DISADVANTAGES OF IBS

Nothing in this world is perfect, so as industrialised building system. Disadvantages of

IBS are as follows:

i. High initial capital cost

The initial capital cost of IBS is usually high. The initial cost including the cost of

constructing the factory, casting beds and support machinery. The cost effectiveness

can only be achieved when undertaking large projects.

ii. Problem of joints

Water leakage is often the major problem in building constructed using IBS. This

problem is more obvious in Malaysia where raining occur rapidly through out the

year.

iii. Sophisticated plants and skilled operators

The prefabrication system relies heavily on sophisticated plants, which have to be

well coordinated and maintained by skilled operators. Breakdown in any one section

would hold-up the entire production line.

iv. Site accessibility

Site accessibility is one of the most important factors of the implementation of IBS.

IBS requires adequate sit accessibility to transport IBS components from factory to

the site.

v. Large working area

Building construction using IBS requires a large working area for the factory,

trailers, tower-cranes and storage for the IBS components. Besides, most

construction sites especially in cities are often congested and unable to provide the

area required.

2.8 OPEN BUILDING SYSTEMS

The utilisation of IBS has made the concept of open building possible. Open

building system is a system that focuses on the need of the user. The concept of Open

Building is best captured by John Habraken's quotes:

We should not to forecast what will happen, but try to make provisions for the

unforeseen (John Habraken, 1961).

In the past, the dream of “living to your liking” is only affordable for those who

can spend a lot of money on their dwellings. Now, by using IBS, this dream is

affordable by almost everybody. Open building system separates a dwelling's utilities

from structural and enclosure systems, in which utility networks typically are

interwoven and buried, thereby liberating the floor plan.

Hence, interior partitions can be eliminated, modified or added easily, and this

allow existing rooms to be expanded, shrunk, merged, or reshaped. This system also

eases replacing or relocating plumbing and electrical fixtures, rewiring, and relocating

ducts and pipes.

2.9 MODULAR CO-ORDINATION

The concept of modular co-ordination was identified as an aid to the utilisation

of industrialised building system. In 1972, the decision to replace the existing imperial

system with the metric system has been made by government. This has lead to the

introduction of modular co-ordination in April 1986. The main reason of the change is

to provide an opportunity for technological advancement and rationalization in building

industry.

According to International Organization for Standard (ISO), the basic principle

of modular co-ordination is 1M = 100mm and this applied on the IBS components.

Trikha (1999) mentioned that modular co-ordination is a co-ordinated unified system

for dimensioning spaces, components, fitting, etc. so that all elements fit together

without cutting or extending even when the components and fittings are manufactured

by different suppliers.

Warszawski (1999) has mentioned two objectives of modular co-ordination. The

first objective is to create a basis for building components to minimize the variety of

types and sizes of building components. Each component is designed to be

interchangeable with other similar ones and hence the designer will have the freedom to

choose which components to use. The second objective of modular co-ordination is to

increase the adoptability of prefabricated components to any layout and their

interchangeability within the building.

2.10 IBS ROADMAP 2003-2010

A fundamental plan that involves all the important aspects is needed in

Malaysian construction industry to evaluate its process. In this respect, the IBS

Roadmap 2003-2010 is formulated as a reference for all parties in implementing all

programs towards the modernization of the Malaysian construction sector.

In year 2003, CIDB has produced IBS Roadmap 2003-2010 as the blueprint

document to be a reference point for the implementation of programmes by all parties

towards industrialising the construction sector. The IBS Roadmap’s main objectives

are:

i. Gradually reduces the percentage of foreign workers from the current 75% to

55% in 2005, 25% in 2007 and 15% in 2009.

ii. Utilisation of IBS for 30% of total Government (Building Projects) gradually

increasing to 50% in 2006 and 70% in 2008.

iii. Towards reaching Open Building system and full industrialization by 2010.

iv. Among main strategies outlined in IBS Roadmap 2003-2010 are:

i) Reduce percentage of foreign workers especially those involved in

wet trades.

ii) Utilisation of modular co-ordination (MC) based on MS 1064

through Undang-undang Kecil Bangunan Seragam (UKBS).

iii) Utilisation of IBS for affordable homes.

iv) Utilisation of IBS in government projects (building).

v) Utilise approved IBS components only

vi) Reduce levy by CIDB for the utilisation of MC.

vii) Green-lane approval of building plans for plans using standard plan

designed according to MC and standard building components.

viii) Training scheme and loan to produce bumiputra IBS producer and

installer.

v. Budget 2005 also reveals that the usage of IBS components in government

building projects will be increased from 30 percent to 50 percent commencing

2005 and housing developers who utilise IBS components exceeding 50 percent,

will be given full exemption on levy imposed by CIDB.

Based on the IBS Roadmap 2003-2010, positive impacts from the fundamental proposal

and new government incentives are:

(i) The industry will choose IBS which guarantees better quality, productivity and

safety.

(ii) The enforcement of using Modular Coordination (MC) through Uniform Building

By Laws (UBBL) will encourage standardization and subsequently increase the usage

of IBS components. It also encourages participation from manufacturers and

assemblers, especially Bumiputera, to enter the market, thus reducing the price of IBS

components. MC will facilitate open industrialization.

(iii) A screening and selection program based in IBS standard components will ensure

that low quality products are not marketed in the country and this prevents the dumping

of foreign IBS products in Malaysia. This aspect is important to avoid failures in IBS

projects

(iv) By reducing wet-trades through IBS, the dependency on foreign workers will also

diminish, thus gaining the billions of Ringgit currently being transferred out by the

foreign workers to their home countries and reducing inherent social problems

involving these foreign workers.

2.11 IBS CONTENT SCORING SYSTEM (IBS SCORE)

As regulatory requirements such as “minimum percentage of utilisation of IBS in

government building projects” and encouragements such as “CIDB Levy exemptions

for a minimum percentage IBS utilisation” have been put forward, a system for IBS

content assessment is needed.

The IBS Content Scoring System (IBS Score) is a systematic and structured assessment

system that can be used to measure the usage of Industrialised Building Systems (IBS)

in a consistent way. The IBS Scoring System emphasizes on the following attributes:

i) The use of prefabricated and precast components

ii) Off-site production of components

iii) The use standardized components

iv) Repeatability

v) Design using Modular Coordination concept

Higher IBS Score is a reflection of a more reduction of site labour, lower wastage, less

site materials, cleaner environment, better quality, neater and safer construction sites,

faster project completion as well as lower total construction costs. The detail

information about IBS Score, methods of calculating IBS Score as well as sample

calculation are included in Manual for IBS Content Scoring System (IBS Score)

published by CIDB.

2.12 BARRIERS TO THE ADOPTION OF IBS IN MALAYSIA

A survey undertaken by CIDB in 2003 found that only mere 15% used IBS in the local

construction industry. According to Waleed A.M. Thanoon et al. (2003) the reasons of

slow adoption of IBS in Malaysia are:

i) Inconsistent of houses demand, high interest rate and cheap labour cost make it hard

to justify large capital investment and it is easier to lay off workers during slack period.

ii) A high degree of precision is required in fully prefabricated construction system

while Malaysia still lack of skilled workers.

iii) Too many parties involve in construction industries. The owners, contractors and

engineers still lack of scientific information about the economic benefits of IBS. This

make the agreement on the utilisation of IBS during planning stage difficult to be

achieved.

iv) Majorities of IBS in Malaysia are imported from developed countries and thus drive

up the cost.

v) The economic benefits of IBS are not well documented in Malaysia.

vi) Most projects constructed with IBS in Malaysia were low quality and high

construction cost. Utilisation of IBS in Japan and Sweden are so successful due to

projects constructed with IBS are high quality and high productivity.

vii) Many architects and engineers still unaware of the basis element of IBS such as

modular co-ordination.

CONCLUSION

There are many types of IBS existing in Malaysia: formwork precast load

bearing wall panel, precast frame, precast floor and hollow core slab, sandwich panel,

block panel, and steel frame. These IBS represent most of the IBS that exist worldwide.

Quality, speed of construction, and cost savings are the main advantages of these

systems. These factors are very important in implementing the Ninth Malaysia Plan.

The main disadvantages of the IBS in Malaysia are that they are highly capital intensive

and there is a need for experts at the construction site for some of them. The main

reason to recommend the use of IBS in Malaysia is that the raw materials used in the

IBS have to be produced locally in order to overcome the shortages that are being faced

by the IBS construction industry.