Finding options to reduce carbon emission should be done during the design concept and planning stage of a project and not at later stages of construction to avoid cost overruns.
Beca - Sujatha Manoj, Technical Director & Geotechnical Services Leader, Australia
The Construction Industry, as one of the largest contributors of global carbon emissions, can also play a significant role in reducing the emissions. Intelligent sourcing of materials, use of alternate and less carbon emitting materials in construction, or optimization of material usage, can go a long way in reducing carbon emissions. Cement and steel are also the largest contributors of carbon emission in the construction industry.
Design solutions can also help reduce material consumption and thereby carbon emission to a great extent. However, the industry should address this in the very early stages of a project. Finding options to reduce carbon emission during the planning and concept design stages can save significant amount of carbon emission in comparison to looking at options at later stages of a project.
Collaborations & partnerships
Decarbonization efforts can only be successful through collaborations amongst all the parties involved. Collaboration has to be a policy decision that includes architects, engineers, designers, material suppliers and contractors. Low carbon solutions as a regulatory requirement can be most effective on large scale projects. In the present scenario, there is social pressure on the construction industry to minimize carbon and measure its carbon footprint. However, regulatory pressure from policy makers can mandate the industry to arrive at the most optimum solutions and implement them in order to achieve net zero carbon emissions.
The parties/stakeholders involved can establish a common sustainability goal by collaborating in the early stages of a project. They can organise workshops to discuss ideas and share knowledge on measures that can be taken towards achieving sustainability in their projects to help arrive at solutions for low carbon emissions.
Promoting a circular economy
The construction industry produces a lot of waste material. Promoting a circular economy, reducing or minimizing wastage, recycling and reusing waste materials, can have a significant impact on the net-zero carbon target. The industry can also deploy advanced digital solutions and systems for generating energy from the waste collected during production and construction. For example, using excavated materials from a tunnelling site can be used to raise the ground level for road work at a nearby site, or using a demolished building’s debris for reuse in pavements etc. are innovative ways to practice circular economy and thereby minimize climate impact. Since, there is a lot of ongoing research in this field, collaborations between the construction industry and the academia can help greatly.
Carbon credits an effective mechanism
Having a carbon credit policy specifically tailored for the construction industry is a good approach to ensure and promote sustainable solutions. A regulatory requirement introduced in a project’s bid specifications to achieve a certain carbon footprint, will make it mandatory for the contractors to achieve the low carbon solutions. It will also help all the contractors to price these efforts in a fair manner when bidding for the work itself.
It is important to adopt a standardized carbon calculating tool to ensure that all parties involved are on the same page in relation to carbon calculations. The carbon calculators specifically designed for construction industry must measure accurately the carbon emissions considering alternate sources, production and transportation of materials, and site-specific data.
The policy makers should establish baseline requirements and include them as part of specifications and possibly include incentives for achieving specific targets above the baseline requirements. Standardized certification and verification mechanism is another way for the regulators to establish these requirements.
A collective approach to drive change
The governments having committed to the sustainable goals of UN and having joined hands in resolutions taken through collective efforts in COP and similar events, the government regulatory bodies will now have to ensure that coordinated efforts are made to achieve net zero emissions. Such regulatory requirements are always better implemented when they are passed down from a central regulatory body to project owners, architects, designers, engineers, and contractors. Such a body can drive the change and raise awareness, set standards and monitor and regulate.
Challenges & solutions
Cost and time implications are the major challenges for construction companies especially when low carbon solutions are looked into late in the construction stage of a project. Even though a low carbon solution may also be a low-cost solution, its late introduction in the project can lead to cost overruns. Also, the contractor may have limited knowledge or awareness of the new technology available for implementing low carbon solutions.
In a recent transportation project in Australia, in which I was involved, the bid documents required that the contractor should achieve low carbon solutions and show that overall carbon reduction was achieved by design alternatives or optimization, and by alternative sourcing. So, the contractor undertook several studies to explore alternative materials to reduce carbon. There was also ongoing collaborative research with a university on the use of demolished building materials for making the lower layers of subgrade in the project’s pavement construction.