Off Site Manufacture For Sustainable Housing Construction Essay

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

As we move into a new decade, the market for off-site manufacture (OSM) is expanding rapidly in order to meet the ever-growing demand for housing in the UK and has initiated a change in to a more holistic approach to the whole building process (ModuleCo 2010).

There are various definitions used to determine what OSM actually is and its processes but it is widely accepted that its simply a term used to "describe any construction process that is carried out away from a building site, such as in a factory or in a specially created temporary production facility close to the construction site" (Riley, M. & Cotgrave, A. 2008).

OSM isn't necessarily a new concept in the construction industry and has been used for many years as a means of providing sustainable housing that is realistically purchasable to a diverse end market (Kelly, R. 1998).

Even back in the early 1900's, the concept of OSM was being pushed for by certain constructionists as an alternative to the costly traditional building methods possessed during these times. The famous German architect Walter Gropius (1924) stated that "…the real solution is that houses should not be built at the site, but in specialised factories" (Sullivan, B.S. 1981). As can be imagined, 'sustainability' was an unheard and unknown of entity back then.

After World War II, OSM was used to replace the many homes that had been bombed. The UK government implemented system building re-using cheap war materials such as aluminium to build the housing as a quick and easily erected remedial solution (Womack, J.P. et al 1990). These houses later became known as 'flatpack' housing (WW2 Talk 2010).

However, despite the benefits to the public brought by these houses, there was still a stigma surrounding their occupation. This is still made apparent nowadays with a majority of pre and post-war housing nicknamed 'tin-houses' or 'tin-towns' (Ireland, B. & Turnball, D. 2006). Although their expected design life was only 10 years (Gibb, A.G.F.1999), many still stand today in cities such as Birmingham and London.

Figure 1 (below-left on next page), shows a picture of the 'pre-fab' Catford estate, South-east London during the 1960's; long after it was expected to last (WW2 Talk 2010).

Figure 1 Source: Bell, R. (2010)

Figure 2 (below), shows how the Catford estate looks nowadays. Its perpetuity has led to the estate to become heritage listed (WW2 Talk 2010) ; a somewhat celebration of the exceptional architecture or historic interest that this set of houses brings to the area (English-heritage 2010).

Figure 2 Source: Bell, R. (2010)

Since the birth of sustainable development (UN 1992), the ongoing debate as to whether it forms an important part of the sustainable construction agenda has continued till present. Reforming the construction process through OSM is seen more of a challenge to the publics own views than it is to the systems surrounding sustainability (Ireland, B. & Turnball, D. 2006).

There is an ever-growing population in the UK, especially within urban areas. The demand for housing currently outweighs the concurrent supply and the pressing need for extra development is evermore urgent. At present, the expected changes in demography of population are projecting a demand for 4.5 million new homes in the next 10 years (Barker, K. 2003). However, during such tough economic times, the feasibility of matching the demand with current economic resources is unlikely to meet the development rates required.

This is where OSM is sold as the answer to all of the construction industries problems (Kelly, R. 1998).

Many question OSM's ability to salvage the housing market but there are strong counter-arguments for adopting its method due to its benefits in terms of production, efficiency, quality and sustainability (Ireland, B. & Turnball, D. 2006).

The environmental impact of housing is becoming an increasingly important consideration for developers and factors such as; choice of materials, method of construction, its occupation, life-span and what happens after its life are all the key elements that OSM tries to allow for in its sustainable approach to mass production (ModuleCo 2010).

An estimated 10% of all building materials that are delivered to site for the use of traditional construction go to waste through not being used (McMullan, R. 2002). This is an extremely large percentage of waste that is contributing to the industries un-sustainable output; the rate to which this can be avoided without drastic changes being put in place is relatively unforeseeable due to its market evolving around a non-static datum. The volatility of this waste increase is expanding due to greater measures of sustainable control and waste reduction (across all markets) (Riley, M. & Howard, C. 2002).

OSM techniques surrounding the use of more efficient materials and supply chain management will also aid a far less wasteful construction process (Riley, M. & Cotgrave, A. 2008).

The increased use of OSM promises to diminish such implications through greater emphasis on the process and whole-life performance of housing (Davis Langdon & Everest 2004). This can be achieved through enhanced specification standards and build quality to reduce occupancy costs related to energy use, defects and repairs (Myers, D. 2008).

Egan's report "Rethinking Construction" (1998) called for a more standardised process and off-site pre-testing to promote a simple repeating structure in quality built housing (Egan, J. 1998).

Due to tight quality control tolerances required by factory mass or/and batch production (UNFCCC 2009), the environmental performance of OSM housing is significantly improved through greater energy efficiency with regards to higher levels of air tightness (infiltration) thus increasing thermal performance of the building (ModuleCo 2010). The lower running costs that are therefore adopted in turn release less carbon emissions. With the government strategy for all new build housing to be zero-carbon by 2016 (DCLG 2007), the adoption of OSM could be seen as a main player for achieving such plan.

This also complies with PPS1 (Planning Policy Statement 1) 2005 of which sets out the governments overarching planning policies on the delivery of sustainable development through the planning system (DCLG 2005).

The increased use of vehicles that would be required to pick up and deliver materials would seem to balance out the reduction in on-site emissions if OSM were to be used. However, 'ModuleCo' say "once the building has been delivered to site, a reduced number of vehicular visits is required (compared to traditional methods of construction), thereby causing less environmental impact on site" (ModuleCo 2010).

Any local environment disturbance such as noise pollution, dust and general on-site nuisances that would have occurred during traditional construction is also eliminated (Myers, D. 2008).

OSM houses can be truly sustainable buildings and can be reconfigured to meet the varying demands of the end-user. Throughout the lifecycle of the building, components such as floor layouts, provision for services and partition assembly can be reconfigured to accommodate the homeowners needs. This increased flexibility allows for pre and post-site refits without the time consummation and cost that is required with traditional construction (ModuleCo 2010).

The building life of OSM housing is technically endless as the materials used in its fabrication can be removed or repaired (more likely to be removed) and simply replaced with a pre-fabricated component of the same nature (Womack, J.P. & Jones, D.T. 2001). Any alterations or amendments that are desired are usually accommodated for by OSM developers so that when necessary, refitting and reusing the building provides an environmentally friendly, genuinely sustainable solution that is future proof (Kelly, R. 1998).

Most components of OSM housing are fully recyclable and therefore can be re-used even in a different form and for a different purpose (Taylor, G.D. 2002).

The pace of development in OSM is increasing with existing players adding capacity and new players entering the market such as Laing O'Rourke and Corus.

In Europe, IKEA have already teamed up with Skanska to create the OSM housing concept 'Boklok' which means 'Live Smart' in Swedish (Slavin, T. 2001).

Its design evolves around providing an optimum "space-saving, functional and high quality housing at a price that enables as many people as possible to afford a stylish and comfortable home" (Boklok 2010).

Figure 3 (below) demonstrates an animated picture of the internal envelope of a typical furnished Boklok house.

Figure 3 Source: Instablog Images (2010)

It has already evolved to currently reach markets in 5 different countries: Sweden, Great Britain, Finland, Norway and Denmark (Boklok 2010).

Recent projects in the UK include one and two bedroom apartments in St James, Gateshead (pictured below; Figures 4 and 5).


Figure 4 Source: Boklok 'b' (2010)


Figure 5 Source: Boklok 'b' (2010)

In the UK, there has been already a fairly significant rise in OSM implementation and large developers seem eager to adapt to the concept to widen and further their market pitch (Ireland, B. & Turnball, D. 2006).

Redrow are already in the process of trying to attract 1st time buyers with their latest concept, the new OSM £55k house (Figure 6, below-left on next page) (BBC, 2005).

It was sited in Wales and its frame was erected out of mainly steel. The foundations were the only element required to be formed on-site. In respect of smaller designs such as 1-bedroom flats, the actual build time was a mere 3 weeks. However, it was noted that for a similar product using traditional methods of construction, the OSM house actually cost slightly more (BBC, 2005).

A digital image of the accomplished project

Figure 6 Source: BBC (2005)

Their latest innovation has been repeated in Rugby, where prices start at a mere £50k (Building, 2008). Figure 7 (below) shows an example of one of the completed enterprises.

Figure 7 Source: Building (2008)

At present, there is a real need to kick-start the housing industry that will conform to the sustainable issues currently being addressed, the question is, is OSM the way to do it?

With a limited array of new forms of housing that conform to the whole 'sustainable development', OSM appears to most certainly tick a majority if not all of the boxes branched from it. Its implementation has already expanding to an extent that it could be defined as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs" (Brundtland, G. 1987), of which is a real precedent set by many countries in the world to bind us all together in one common notion.

The general consensus is that the UK construction industry needs to invest more into research and development (R&D) if OSM is to succeed as it has in countries such as Japan (UNFCCC, 2009). Approximately 20% of Japans housing is pre-fabricated and their respective investments in R&D have allowed them to utilise OSM as such a large portion of the market sector (Ohtake, F. & Shintani, M. 1995). To differentiate the scales in which Japan and the UK operate is exemplified with the recent statistic that Japans leading housing developer invests more into R&D than the entire UK building research budget (Justlanded 2010).

However, it needs to be borne in mind that where and how OSM is enhanced plays an extremely important role in the long term success of the concept. Careful analysis is needed to ensure that a repeat of pre-fabricated housing like in some parts of eastern Europe is avoided to prevent the formation of 'slums', thus weakening the promotion of sustainable communities through a sustainable form of construction (NHF 1997).

If OSM is successful and the share in the market it possesses expands, the ability for developers to run on minimum capacity due to pre-fabrication of products in factory-controlled conditions (Myers, D. 2008) will bring potential problems to the business stakeholders. The more than likely resulting redundancies or cut-backs of workforces begs a difficult yet needed question, do we want to be releasing employees into a climate where unemployment is already high?

It is somewhat niche in its sustainable output as it is difficult to fully define as being either sacrificial to the people at present or the future generations.

Although the use of simple pre-fabricated components has increased in most sectors in the industry, the endorsement for more integrated OSM systems has been more uneven (Venables, T. et al 2004).

Without raised awareness and a change in attitudes towards sustainable housing as a whole, its adaptation to the private housing building industry will be uncertain as the premium construction costs of OSM are difficult to justify in a market focused on location and price rather than quality and lifetime performance (Davis Langdon & Everest 2004).