What is Sustainable Construction? Building More with Less
In a previous blog post, I talked about embodied carbon and the environmental impacts of the construction phase of a project’s life cycle. Now let’s have look at the collective impact of the wider built environment—and how the construction industry has a leading role to play in transitioning to a net-zero world.
We don't have to stop building—but we do need to change the way we design, build, occupy, and use what is already available to us. We need to leverage the materials and existing buildings we have and design spaces that are more resilient to changing use patterns—and able to last further into the future.
MILWAUKEE METROPOLITAN SEWERAGE DISTRICT'S CUSTOMER STORY
The Environmental Impact of Construction
Construction and the built environment contributes about 39% of total global carbon emissions and about half of all extracted raw materials. Unfortunately, these trends don't appear to be decreasing. Due to population growth and urbanization, some estimates predict we will need to build an additional 3,600 buildings a day in urban areas alone. On the other hand, the US Census Bureau estimated that there were nearly 17 million vacant homes in 2019.
So why are we pursuing new construction when vacant homes are available? Often, the vacant homes tend to be in less desirable locations where finding employment is difficult. However, with digital technology transforming every sector and the COVID-19 pandemic driving an upswing in remote work, labor habits are changing. With more and more people leaving the city to work remotely, perhaps these undesirable locations could and should be of interest again.
But promoting vacant homes in less desirable locations will not be enough to solve our climate crisis—so how can we move to a more environmentally resilient industry?
The built environment in the US accounts for 30% of all greenhouse gas emissions, so transitioning to greener forms of heating and cooling can have a significant impact.
7 BENEFITS OF SUSTAINABLE CONSTRUCTION
To keep global temperatures from rising more than 1.5°C, we need exponential change in our industry and the fastest economic transition in history. To an industry that is historically change averse, this is a daunting task—but it’s also a positive growth opportunity to achieve the productivity and efficiency gains we have been striving toward for the past 20 years, in addition to the environmental benefits.
Sustainability building will no doubt become more prominent over the next few years; however, the benefits of sustainable construction fall into three main buckets: environmental; financial; and social.
- Reduction of environmental impact - recycled materials and environmentally efficient products used during construction reduce waste and contribute to preserving our environment.
- Improved health - green construction and furnishing materials can improve the overall health and wellness of construction crews as well as future building occupants.
- Increased productivity - eco friendly workspaces are shown to enhance employee morale, work performance, and perhaps even job retention.
- Green utilities - buildings built with solar power, water recycling systems, etc. will enjoy cost effective utilities that are sustainable.
- Waste reduction - green buildings minimize waste via the use of renewable sources and materials, while also alleviating the environmental impact.
- Cost reduction - when done right, green buildings cost less to construct and long term, less to maintain than normal buildings.
- Future-proofing - new eco friendly materials are being invented all the time and begging for innovative applications to better our world.
An economic disruption on this scale will be the catalyst for the overall digital revolution of this industry.
5 Strategies to Make Construction More Sustainable
To help us understand the changes required in the construction industry, a multi-disciplinary team from academia, business, and NGOs have authored a report called the Exponential Roadmap. This roadmap outlines in detail where we need to focus our efforts and the steps we need to take. As a sector, annual emissions related to existing buildings were about 9.9 Gt CO2e in 2016 and decreasing slightly. To put this figure into context this is approximately the same as 2.1 billion cars being driven for a year!
According to the Exponential Roadmap, “Annual emissions related to construction, on the other hand, are increasing steadily and reached 3.7 Gt CO2e in 2016. As of 2016, there were 235 billion square meters of building space globally, which is more or less expected to double by 2050 in a business-as-usual scenario.” In order to achieve a 1.5°C world, we need to reduce our emissions by 50% by 2030, again by 2040, and achieve net-zero in 2050. Here are the steps we need to take:
1. DOUBLE RETROFITTING TOTAL
The most impactful change we can make is to reuse the existing assets and materials we have available to us. This change needs to start at the inception and design stage, where the first question we should ask is, “Do we need to demolish what is already there and rebuild new?” If the answer is no, we need to incorporate retrofitting and expansion into our scope and design plans. In some cases, the cost of retrofitting versus new build will be prohibitive, and we need policy and financial incentives to enable this transition.
2. REDUCE DEMAND FOR BUILDING SPACE
This transition is already underway in some sectors, such as retail stores, banks, and postal services, where consumer habits are moving online. Where appropriate, we need to escalate the pace of this change while taking into account the negative impacts resulting from the transition to online shopping, such as abandoned shopping malls and downtown areas. Our priority should not be to reduce space utilization but instead to optimize. How can we use existing spaces most effectively? Consider a coffee shop that has a low space utilization rate over a 24-hour period, and there’s a direct correlation between space utilization and potential revenue. Could space utilization be increased through shared occupancy models? For example, the coffee shop might transition to a bar after hours. As commercial businesses find a new normal after the pandemic, they’re looking for a balance between remote working preferences and returning to the office. To accommodate these changes, some businesses are considering shared desks concepts, allowing for increased occupancy rates.
3. REDUCE ENERGY USE DURING OPERATION
In line with optimizing our demand for space and increasing our retrofitting total, we also need to optimize energy use. Utilizing concepts such as performance-based design to maximize energy efficiency, daylight, thermal comfort, and HVAC sizing will allow us to reduce energy demand while also allowing for increased occupant wellness. In addition, smart sensors to detect movement and zoning systems to help provide optimal energy use can have a big impact.
4. LOW CARBON HEATING AND COOLING
The built environment in the US accounts for 30% of all greenhouse gas emissions, so transitioning to greener forms of heating and cooling can have a significant impact. Green certifications such as LEED contribute both to reducing emissions and reducing opex costs. Some case studies show that energy-efficient design can reduce a building's energy consumption by as much as 50%. Additionally, individual investments in renewable energy sources such as solar offer opportunities to scale renewables exponentially.
5. LOW CARBON CONSTRUCTION
Embodied carbon is the sum of all greenhouse gas emissions resulting from the construction lifecycle of a building. This includes emissions resulting from material extraction and transportation, the construction phase, operation, and demolition. These emissions account for 11% of total global carbon emissions. The scale of the emissions means that we need to transition to greener construction. How do we reduce our emissions from construction? The first step is to understand and measure what our embodied carbon emissions are across the entire construction lifecycle, from material procurement to demolition. Once we can quantify our emissions, we must set a baseline and reduction targets. Some small steps we can take are to source material and equipment from local vendors and investigate transitioning site equipment to electric alternatives.
A more sustainable business model
Transitioning to a more sustainable business model is not a one-size-fits-all solution. It will vary depending on the sectors we serve. Most of us have heard that sustainability means increased upfront capex while resulting in reduced opex. This point of view is most applicable to our owners, but may not translate across the rest of the value chain to GCs or speciality contractors.
So how can our entire industry move to a new business model?
Automotive manufacturing is a comparable industry to consider, where in the past, policy and regulatory changes to adopt a green economy have been successfully lobbied against. In the past year or two, however, the electric vehicle boom has progressively changed the industry’s perspective. With the monumental growth of Tesla, recognizing gains in the region of 700% in 2020, the wider industry is waking up to this opportunity. General Motors, an established player in this space, recognizes the tide has turned and they can either be disrupted or embrace change and innovation.
We in construction need to recognize that we are in a pivotal moment to embrace change and move to a green economy—or be disrupted along the way.
But what’s in it for me? To answer this question, let's “follow the money.”
Our financial systems and markets have awakened to sustainability. It is estimated that the global economic benefit of a low-carbon future is US$26 trillion by 2030 compared with staying on the current high-carbon pathway.
On Wall Street and global markets, 160 companies overseeing US$86 trillion in assets have signed up to the G20’s Task Force on Climate Related Financial Disclosures (TCFD) which asks companies to disclose their exposure to climate risk. ESG (Environmental, Social & Governance) investing is now one of the fastest growing asset classes, and studies show that companies who are rated highly in ESG are outperforming their peers.
The construction industry is heavily reliant on access to external funding and access to this funding could start to become conditional based on presenting a strong case for ESG. In some global areas, such as the EU, this transition is already starting. The EU Level(s) framework provides a common language for building sustainably and can be used to help bring building projects into the circular economy.
The transition to ESG funding will propagate across our industry as more RFPs will require sustainable thinking. Vendor selection will factor in a commitment to the environment and decisions will be based on demonstrating examples of this commitment. We have an opportunity now to move to a more sustainable future while also recognizing that this transition is aligned with the financial success and health of our organizations. The future is bright, but we need to act now.