Decarbonising the Construction Industry

Decarbonising the Construction Industry

13/08/2021

In a comprehensive and detailed report, international colleagues from the McKinsey management consultancy firm have published a breakdown of the construction industry’s decarbonization efforts, highlighting the importance of design to a building’s sustainability. With rising corporate awareness of the issue, and with governmental and customer interest in energy-efficient housing growing all the time, creating a sustainable sector benefits everyone. The report can be accessed in full here: https://www.mckinsey.com/industries/engineering-construction-and-building-materials/our-insights/call-for-action-seizing-the-decarbonization-opportunity-in-construction 

The Construction Industry’s GHG Contribution

While environmental, social, and governance, or ESG, metrics attempt to gauge the sustainability of a business as a whole, for the construction industry, it’s the environmental factor that relates directly to the issue of greenhouse gases (GHG).

 Evaluating the construction sector’s contribution to global GHG emissions is not easy. However, the McKinsey article estimates the industry is responsible for around 25 percent of total GHG emissions and 40 percent of carbon fuel combustion contributions.

Aside from GHG emissions, the other areas that the construction industry needs to address are:

-Waste production

-Water consumption

-Particulate matter air pollution

Though the article focuses specifically on the emission of GHGs, it establishes that these additional issues are something that a sustainable industry would need to look at. High water usage, for example, is well-known for carrying with it a considerable carbon footprint, with the industry currently requiring 200 liters of water per cubic meter of concrete.

The two key aspects of the construction ecosystem that are driving up GHG emissions are the raw materials used in infrastructure and building, and the lifetime operation of the building itself.

 The manufacturing and processing of materials are estimated to account for around 30 percent of the industry’s carbon emissions per year, with most of this coming from cement and steel production. Building operations account for the other 70 percent. This operational contribution is attributable to the poor insulation and energy inefficiencies of existing buildings.

 Early-stage designing with sustainability in mind is the best way to reduce a building’s lifetime GHG contribution. These design measures include multi-use or flexible floor spaces, building size considerations, and due consideration of whether renovating or repurposing existing buildings would be a more efficient option. 

However, with the Net Zero target of 2050 well-established and almost 80 percent of the building stock for that date already built, the necessity for retrofitting to meet sustainability goals is clear. If unmet, the issue will compound with construction’s carbon output expected to grow as it tries to meet growing demand, which in Ireland, is now close to 50,000 new homes per year.

Carbon Abatement: Existing Builds

As mentioned above, to achieve the Net Zero goal, the report authors argue that it will require not only sustainable design and building of new assets but also the reuse of existing stock. They believe that there needs to be clear goals for all players within the industry, however, the report anticipates that achieving these goals will result in substantial cost savings over the longer term. It should be noted that the decarbonization pathway for construction has an average cost per tonne of CO2 that is significantly lower than other industries. Also, heating is considered one of the key ways to curtail CO2 output.  Up to 70 percent of the EU’s energy use is directly related to the heating of buildings. This high energy use is down to the existing building stock’s thermal insulation being insufficient and poorly designed heating control systems. Upgrading insulation can reduce the energy demand of a building by 30 percent over a 50-year lifespan.

 Complimenting the improvement of these is the increased use of renewable energy to deliver heat to these buildings. This abatement method involves moving the industry towards the use of heat pumps, district heating, biogas, and solar thermal where possible. The McKinsey authors argue that increased use of such renewable heating technologies would see a 72 percent reduction in operation emissions within buildings and drive the cost of the technologies down over time.

GHG Emission Reduction in New Builds

With such a high proportion of the GHG emissions relating to operations locked into existing builds, the report considers a pathway for net-zero carbon with new builds. This primarily involves the decarbonization of materials.

This can be achieved through three key measures:

– Demand reduction and circularity. This involves reducing waste, increasing the recycling of materials, and designing so that primary resource demand is lowered.

– Optimizing construction and material use. By switching to high-efficiency, low-carbon materials through offsite production and modern methods of construction (MMC), the industry can drastically reduce its overall carbon footprint.

– The decarbonization of materials. By reducing the CO2 emitted during the production and processing of materials, the industry can further its way to sustainability. This can involve the increased use of electrification in the process and implementing production efficiencies and technological advancements.

The use of low-carbon materials, offsite production and other MMC is likely to be the most impactful way for the industry to achieve its net-zero goal.

 Critically, with any given construction project involving many different players, industry-wide cooperation is needed to achieve carbon neutrality. The McKinsey report suggests this may well involve some drastic changes in philosophy, particularly around up-front costs versus lifetime costs of a building. It will also require a major shift towards MMC and the implementation of nascent technologies. As the report points out, “…the drive to sustainability is racing ahead…accelerating this journey and addressing the challenge head-on will be the key”.

About McKeon Group

Established in 1950 and ISO certified for more than two decades, McKeon Group offers expert construction, fitout and building services. The family-run Group delivers projects, services and maintenance across a range of sectors for State, local authority, FDI and private clients. For more information, contact: www.mckeon.ie