ARCHITECTUREDESIGN

Net-zero and Role Of Modular Construction in Construction Industry

Net-zero in Construction

What is Net-zero?

A recent report by the Intergovernmental Panel on Climate Change has painted a Red Alert to humanity as it described the urgency needed to achieve Net-Zero emissions. This led several global actors like the US, Japan, Australia, and the EU to commit to a net-zero emission by 2050.

Net-zero refers to a globally agreed-upon goal of completely negating the amount of greenhouse gasses in the atmosphere by reducing the amount of carbon emissions and implementing mechanisms that will absorb the already existing carbon dioxide from the atmosphere. It is a target to balance the amount of carbon dioxide emitted and removed from the atmosphere.

Sustainability and Net zero

Net-zero in the construction industry

For a long time, the construction industry has been criticized for its rigidity and slow adaptation to change. The sector must desperately achieve net-zero to heed the dire plights of global environmental concerns.

The construction industry contributes to about 40% of total carbon emissions in the UK alone. Studies further point out that construction waste accounts for 32% of landfills. 13% of construction material taken to these sites remain unused and ends up in landfills.

The industry stakeholders have accepted a need to ensure that any project results in minimal greenhouse emissions. The whole chain of construction from material manufacturing, transportation to site, construction process maintenance to the end of design life disposal.

Clients and developers have shown interest in constructing net-zero buildings as an individual initiative. To this effect, designers have come with a step-by-step approach to realize this goal.

Achieving Net-Zero in Residential Building

Façade design. This design ensures maximum use of daylight index by occupants of a building. This will limit artificial lighting use, reduce glare heat loss, reduce cooling loads, and provide comfort to the occupants. When adequately designed, the net need for lighting and air conditioning energy will realize a significant drop.

Minimize demand for operational energy and consumption. Prioritize measures that would drive down heating and cooling demands. This could range from designing buildings that allow for natural airflow to embedding heat insulations in building materials.

Eliminate fossil energy. Designers are encouraged to prioritize modern heat sources like electric heat pumps over fossil energy sources.

Limit upfront embodied carbon. Restricting carbon intensity to a maximum of 500kgCO2/m2. This must apply to the entire construction cycle, from material extraction to building decommissioning.

MODULAR CONSTRUCTIONS AND HOW IT IS AFFECTING THE CONSTRUCTION INDUSTRY

Modular construction refers to the process where buildings or building components/modules are constructed in a manufacturing facility, off-site, following all the required design codes and state laws. These components/modules are then transported and assembled on-site while meeting the design intent and sophistication as would have been for the site-built facility.

History of Modular Construction

Modular buildings can be traced back to the 1600s when an English fisherman wanted to relocate to America but only trusted buildings made to English Standards. The solution was to ship disassembled home across the Atlantic by boats.

During the California Gold Rush, quick housing solutions were needed. Factories in New York built and shipped over 500 houses to California. After the first world war, companies like E.F Hodgson, Sears, Roebucks, and Montgomery Ward made thousands of modular homes for returning soldiers.

During the second world war, there was a growing need for rapid building construction to replace bomb-damaged buildings. These structures usually stood beyond their design life examples are the temporary World War two classrooms still in use. The degraded modular structures became less attractive and fell out of favor.

Most recently, China managed to build a 25,000-square-meter Huoshenshan Hospital to deal with the patients of the Covid-19 virus in just ten days. This is the quickest construction ever witnessed in the industry. Modular construction helped in most part to achieve this. Modules were manufactured in an offset facility allowing for foundation work to continue.

Netzero
Photo Credit: Construction at Huoshenshan Hospital Modules craned on site. Source BBC News. 2nd Feb 2020

The two types of Modular construction

Permanent Modular Construction.

It is a construction process utilizing offsite manufacturing solutions to pre-construct single or multi-story whole building solutions in module sections. These modules are then transported and assembled at the permanent building site.

Modular Construction
Photo Credit: Permanent Modular Construction. Source: Modular Building Institute

Relocatable Buildings

Relocatable buildings are partially or wholly integrated buildings made in a manufacturing facility through the modular process but designed to be reused or repurposed severally in different sites. Examples include mobile clinics, classrooms, site offices, and sales centers. Their purpose is to serve the temporary need for space.

Modular
Photo Credit: Relocatable Building. Source: Modular Building Institute

Effects of Modular Construction in the Industry.

Modular buildings are structurally stronger than their site-built counterparts. Each modular component is designed to withstand vigorous transportation and craning process.  Better quality management is realized when doing off-site construction. There are stringent and independent inspection and testing protocols in these manufacturing facilities.

There has been the need to upgrade old buildings in city centers and areas of high activities like markets and schools. Modular construction has been handy as over 70% of construction activities can be moved off-site. This has reduced vehicular traffic, reduced site disruption, and increased overall safety in such areas.

Compared to traditional buildings, a 30% to 50% reduction in project completion time has been realized using the modular process. Modular construction can happen simultaneously with other site activities like site clearance and foundation work.

Schedule

Environmental concern has driven the industry to adopt greener construction processes. Since modular construction is a factory-controlled process, less waste is generated, and many matrials are recycled

Conclusion

Climate change has become a threat today rather than a distant future concern. The construction industry has recognized the need to incorporate net-zero emissions in their designs. Clients and developers are rather brave and are actively seeking ways that their building can contribute to achieving net-zero. It is time for the entire industry to buy into net-zero emission solutions for a sustained future of the planet.

With modern technology, there was a recognition that modular buildings can be aesthetically pleasing and achieve build quality as other on-site structures. Modular construction has brought faster completion of projects, less material wastage, safer construction, and an environmentally friendly process.As industry participants from developers, designers, and contractors learn and appreciate this new process, more modular construction will be expected in the future.

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