Volumetric Versus Panelised Construction: Examination of Case Studies

Volumetric versus panelised construction an examination of case studies

Innovare / Offsite construction – More Adaptable than Many Realise

1.     Background and aim

In the past decades, the construction industry has been strongly encouraged to increase its use of Modern Methods of Construction (MMC) to solve the problems of shortage of supply and poor quality of built housing. Despite many advantages, the construction industry has been slow to adopt them. (Pan, et al., 2008)

Offsite construction is part of MMC; it is the manufacture and pre-assembly of elements in a factory before installation into their final location.

Nowadays, with the world’s demographic explosion, offsite construction has become more than ever as an essential methods for cities that are struggling to provide their population with sufficient housing. To solve the global housing crisis, it is increasingly evident that offsite housing marks the beginning of a new era. Offsite construction is on its way to boosting the economic productivity of the construction sector on a global scale. (Chazal, 2019)

Offsite construction is classified in four main overall categories: panelised systems (2D), modular or volumetric system (3D), subassemblies and components (2D or 3D) and Hybrid systems (2D+3D). (Hairstans, 2014)

The project will focus on two of these systems: panelised and volumetric. Panelised systems are divided in two categories, closed panels are provided with insulation, external cladding, windows and doors already factory installed, and open panels, which is only the frame ready for external joinery to be placed. Volumetric systems are delivered onsite with complete interior and exterior finishes. (Davies, 2018)

The aim of this Honours Project is to compare the market of volumetric and panelised systems and to determine the environmental and economic impacts these methods have on the construction industry in the United Kingdom.

Keywords: modular construction, offsite manufacture, Modern Methods of Construction (MMC), open panels, closed panels, panelised systems, volumetric system

2.     Research agenda

• Definition and overview of the Offsite construction industry. Highlight the advantages and disadvantages of this construction’s method. Identification of the different market drivers and suppliers.

• Study of panelised systems, open and closed panels: production flow, transport onsite, construction methods, price, waste management, SWOT (Strengths, Weaknesses, Opportunities, and Threats)

• Study of volumetric systems: production flow, transport onsite, construction methods, price, waste management, SWOT (stands for Strengths, Weaknesses, Opportunities, and Threats)

• Case study analysis: companies specialized in panelized and volumetric systems, construction methods, size of the project, suppliers

• Comparison and critical analysis of the findings which highlight any possible improvement

3.     Review of current knowledge

1)     Modern Methods of Construction (MMC)

The term “Modern Methods of Construction” also called “smart construction”, appeared after the Second World War to deliver fresh accommodation rapidly. The aim of MMC is to use offsite manufacturing techniques to reduce the defects, the cost and be more efficient. However, after many failures using MMC, traditional house building techniques have returned. (NHBC Foundation, 2016)

Many reports have been published since the 20^th century to modernize the methods of construction. In 1998, Sir John Egan published “rethinking construction” to improve the efficiency and quality of the construction in the UK. In this report, he proposed modernizing the construction industry by focusing their efforts on the needs of the customers by reducing the construction cost, the construction time and a reduction in defects. (Egan, 1998)

The Construction Leadership Council ordered a new industry report in 2016, “The Farmer Review of the UK Construction Labour model”, which examined the actual labour model and proposed measures to protect the future of the industry. The report highlights the different problems of the construction sector: lack of collaboration and innovation, non-existent research and development and the increase of costs. Mark Farmer has identified a crisis in this sector and concluded that the construction industry must “modernise or die”. (Farmer, 2016)

Despite these reports, the construction industry in the UK has been slow to accept new construction methods. Offsite construction, which is part of Modern Methods of Construction (MMC), considers the results of the studies that have been carried out in order to modernize the construction industry. (Duncheva & Bradley, 2019)

In comparison to traditional construction methods, timber offsite construction has many advantages:

-          Build faster, the average lead times observed for off-site construction are 50% of those of conventional construction

-          Less inconvenience, reduction of the inconvenience caused by the construction site, faster commissioning, lower thefts risks

-          Quality improvement, everything that is done in the factory could be done better than what is done onsite, onsite controls

-          Waste reduction, factory construction allows for better material management

-          Easily transportable, timber

-          Uses local workforces, creates stable jobs and encourages skill development

-          No weather problems, neither time loss nor degradation of stock

On the other hand, offsite construction may have some issues:

-          Large investment for the company, cost of buildings, electricity and machines

-          Limitations, transportation restrictions due to the limited size

-          Failure, not only successful project

-          Limited design, due to the modular nature of construction

In addition to that, despite all the benefits there is still a general lack of acceptance for the new building method. (Fenner, et al., 2018); (Hairstans, 2014)

2)     Panelised and volumetric systems

The arrival of new technologies and the increase in demand for housing has led the construction industry to build offsite. The two construction models, panelized systems and volumetric construction, are the two main methods of offsite timber construction.

Panelised systems – 2D elements

Panelised systems can be “open” or “closed”. Open panels are usually non-insulated and closed panels are normally insulated. The 2D construction technique allows these panels to be under constant quality control. As a result, these walls are perfect in terms of alignment, parallelism, or sizing. The resulting panels are strictly in accordance with the specifications.

There are three types of prefabricated panels: walls, floors and roofs that are divided in four categories:

-          Uninsulated panels on only one side

-          Insulated panels without finishes

-          Insulated panels finished on one side

-          Insulated panels fully finished (Built Offsite, 2016)

Volumetric systems – 3D elements

Volumetric systems described modules which are fully finished internally, and which are then installed onto or in a building, such as bathrooms. The components are manufactured and pre-assembled in the factory. This manufacturing method makes it possible to deliver quickly.

3D modules are also divided in four categories:

-          Uninsulated modules

-          Insulated modules without finished fittings

-          Insulated modules with finished lining on one side

-          Modules fully finished on all sides with integrated services (Built Offsite, 2016)

4.     Research methods/ Procedures to be used

• A research on the market of the offsite construction industry in UK will be detailed with relevant scientific articles.

• A study of panelised and volumetric systems will be achieved on different comparison criteria such as production flow, transport onsite, construction methods, price, waste management. Potential case studies could be identified throughout this research.

• A comparison and critical analysis of the findings will be detailed with a highlight of any possible improvement.

5.     Data requirements and analysis

The data will be obtained from the literature search by using keywords from different sources such as journals, books, official reports, articles and other significant documents available in databases and libraries. These data will be analysed for a better understanding of the subject and support by cases studies. Interviews with professionals in the off-site construction industry can also support my research.

6.     Resources requirements

This topic is mainly based on research. The use of technical software will not be necessary except Microsoft Office for editing. The advice and support from the supervisor are considerable resources and multiple appointment will be planned throughout the Honours Project duration. The management of the time will also be a major resource to carry out this project.

7.     Timetable

8.     References

• Built Offsite, 2016. Dimensions of design for prefabrication: 2D, 3D, Hybrid. [Online]
  Available at: http://builtoffsite.com.au/issue-02/dimensions-design-2d-3d-hybrid-components/
  [Accessed 11 10 2019].
• Chazal, P., 2019. Strasbourg, le bois se hisse au sommet. Hors-Site: Le magazine de la construction moderne, Volume 6, p. 3.
• Davies, A., 2018. Modern Methods of Construction; A forward-thinking solution to the housing crisis?, London: RICS.
• Duncheva, T. & Bradley, F. F., 2019. Multifaceted productivity comparison of off-site timber manufacturing strategies in mainland Europe and the United Kingdom, Glasgow: Journal of Construction Engineering and Management.
• Egan, J., 1998. Rethinking Construction, London: Department of Trade and industry.
• Farmer, M., 2016. The Farmer Review of the UK Construction Labour Model, s.l.: Construction Leadership Council (2016).
• Fenner, A. et al., 2018. Outcomes of the State-of-the-art Symposium: status, challenges and future directions of offsite construction, Hollywood: World of Modular.
• Hairstans, R., 2014. Building offsite: an introduction. Edinburgh: UK Commission for Employment and Skills (UKCES).
• NHBC Foundation, 2016. Modern methods of construction: Views from the industry, London: IHS BRE Press.
• Pan, W., Gibb, A. G. & Dainty, A. R., 2008. Leading UK housebuilders’ utilization of offsite construction methods. Building Research & Information, 36(1), pp. 56-67.