The panelized off-site building technologies could also involve exterior wall of building designed to provide the load bearing structural support, and the panelized building system could be made of light gauge steel, timber, structural insulated panels (SIPs), non-structural or concrete, which could be used to create the whole building. (Parliamentary Office of Science and Technology, 2003). On the hand, Burwood and Jess (2005) reveal another method of panelized building system which is closed system. However, closed system is more complex because it involves the use of more factory fabrication such as insulation and lining materials. Different type of panels may include steel frame or timber frame and they may consist of prefabricated load bearing panels.

There are several advantages that could be derived from using panelized system for house building:

First, the panellized offsite building system offers labor saving since the panels is already manufactured in the factory.

Additionally, there is a great reduction in the construction time and provide the lesser wastage of building materials. Builders claim that a watertight home could be assembled and completed within 3 to 4 days, and the home could be occupied within 60 to 90 days. More importantly, a group of construction workers with a trained supervisor could assemble a panelized home, and the system does not require much shipping clearance. Ely (2006) argues that panelized system is pre-insulated and highly quality controlled within the factory.

Fig 1: Labor Saving using Panelized and Modular Building System

Source: National Audit Office (2005)

Illustration in Fig 1 shows that labor saving could be greatly reduced using modular system to build a house. Addition, labor is saved using panelized system compared to the traditional brick and block system.

Despite the benefits derived from using the panelized offsite building system, the system is not as efficient as modular system. Moreover, the system needs a high level of finishing on site, and there is a need to have a high volume of space to use this system for home building. (Ely, 2006).

2.1.2: Modular System

Modular offsite building technology is a form of building structure that can be pieced up together to make a flat. The modular is often frequently used for kitchens and bathroom, and between 80 and 90% of modular homes are often constructed in the factory and transported to the site for final assembly. The "pre-fabricated modules are often referred as pods" (Burwood and Jess 2005 P1) and the pods could be finished in the factory and completed with the mechanical and electrical wiring. The pods could also be constructed using light-steel frame, timber frame, concrete super structure and hot rolled steel frame. (Burwood and Jess 2005).

There are benefits that modular system offers to the housing building construction industry. First, the modular building system could be designed with the aid of a computer-aided design making the final design to be transferred to the factory floor. The system also provides the benefits of fully finishing in term of internal finishing, and there is a high degree of quality control within the factory.

The system also allows for better efficiencies and improved economic of scales within the house building sector. Moreover, the modular systems offer better construction standard since the walls are designed to enhance energy efficiency. More importantly, walls built with modular system are stronger than the traditional brick and block, and modular materials could be used to construct temporary homes since building could be taken apart and reconstructed at another location. A builder could use lesser time in building a home using modular system and wastage of construction materials is high minimized.

National Audit Office (2005) also argue that labor use could drastically reduced using panelized and modular system for home building, and it is possible to build four times of homes using the same on-site labor. The decline in the on-site labor has made the labor costs to be reduced when using the off-site technologies building a home. From the author' perspective, panelized and modular building system improves business efficiency and offer quality and customer satisfaction. The major factor making the system to use less labor is that significant part of the work is already undertaken in the factory Additionally, both system offers reduction in the time used to build a home. For example, a builder could use 16 weeks to build a house using panelized and modular system compared to traditional brick and block system which requires 39 weeks to build a house.

Despite...

Typically, the cost of manufacturing components used for the off-site building materials make the costs to be higher, and some materials are not available within the UK. Some of the materials need to be imported from abroad.
Despite the increase in the overall costs of completing a house using panelized and modular system, the systems offer a high housing quality and durability compared to the traditional block and bricks. Typically, a home built using the light steel frame system could have the life span of 200 years. Thus, off-site system for home building meets durability, high performances and whole life costs requirements. Similarly, Parliamentary Office of Science and Technology (2003) reveals that MMC offers economic benefits because the MMC houses typically have fewer defects, and could be more energy efficient than the traditional brick and blocks houses.

Despite the benefits derived from using modular off-site technologies for home building, the shortcoming of the system is that a builder needs a clearance before shipping the modules to the site. Moreover, there is a little opportunity for homeowner to inspect the home on-site since the modules are fabricated at the factory. Since some of the materials used for its fabrication are imported, the system requires a higher degree of skilled installation on site. (Ely, 2006).

Meanwhile, it is important to understand the attitudes of the construction companies, lenders, insurance companies and government towards the panelized and modular technologies to enhance the greater understanding on the importance of panelized and modular building system in the UK.

2.2: Attitude of Government towards Panelized and Modular Building System

"The government is aware of the importance of developing a capable construction industry driven by technological developments in the manufacturing and service industry that is able to contribute in a large scale towards the economy of the sector" (Azman et al. 2010 P. 4478).

Since 1960, there has been a problem of the housing shortage in the UK due to the downward trend in the housing supply. At the same time, there has been a gradual increase in the number of households due to the increase in the immigration into the UK. With the increase in the influx of people into the UK, there is a forecast that the number of households in the UK will increase to 3.8 million between 1996 and 2021, which is equivalent of 150,000 increases yearly. Recent statistics reveals that the increase in the new households will be more than 150,000 formerly estimated and the new households could increase to 189,000 yearly. (Barker, 2003). Given the increase in the demand for housing in the UK, and the increase in public concern whether the traditional housing supply could meet the current demand for housing, the UK government set up the Baker review. (Barker 33 Cross Industry Group, 2006, Barker, 2004). Baker warned that the under-supply of the housing unit in the economy might constrain the economic growth and prosperity. Baker (2003) suggested that the offsite technologies could address the current housing shortage, the quality issues and skilled shortage in the construction industry.

The primary drivers for making the UK government to focus more attention on the off-site technologies for building homes is due to the shortage of housing in the UK. Typically, the housing demand in the UK exceeds the housing supply. The current supply of new housing in the UK is approximately 175,000 per year, which is not sufficient for the demand for housing in the UK. Typically, the demand for housing is on the average of 230,000 per year, and it is estimated that the housing demand is likely to increase to 3 million by 2016. In the South-East England, there is a shortage of affordable housing for key workers and the Treasury's Baker review warns the consequences the shortage of housing supply could bring to the economy. Typically, the UK government has played a key role in encouraging builders to build more housing using MMC. For example, the UK demonstrates the key interest to build approximately 200,000 houses by 2016 at Thames Gateway, Stansted-Cambridge Ashford and Milton Keynes in the UK.

Additionally, the UK government renewed interest on MMC is encouraging. From 2004, the housing corporation has focused its interest on the MMC policy by providing funding to build equivalent of 5,000 social housing units per year using MMC. In 2005, there was an agreement between the English Partnerships and…