Insights from 20 Years of Working with Green Building Projects
When my partner and I decided to dedicate our professional lives to facilitating sustainable green buildings two decades ago, we started with housing projects. We knew that we wanted to make a difference in the lives of everyday people in the places that they live and work. And we believed that incremental improvements in quality of life would result in a better understanding of the relationship between everyday people and the environment. We still believe that.
Though sustainability is not a new concept, it seems that every generation engages with it and approaches its tradeoffs differently. Here’s our take on what has changed over the past two decades and what has not.
Energy Modeling was a very new and little understood task 20 years ago. Its use to estimate annual energy use based on a building’s design was typically only used for high end mechanical design projects with expensive building systems. Then along came LEED certification which required energy modeling, based on an ASHRAE standard, to be done first as a Prerequisite and then to achieve highly prized energy optimization points.
As LEED gained traction in the marketplace, so did energy modeling. Over time energy modeling became more common as an approach to code compliance in places concerned about energy efficiency, carbon and greenhouse gas emissions. However, its increasingly common application did not improve the understanding of how to make the best use of energy modeling or the reasonableness of the results.
Mechanical system design has always been a challenging area, a highly technical realm of equipment interactions, energy trade-offs and sometimes complex calculations. Energy modeling compares the interaction of the proposed design of envelope, mechanical and lighting systems with what is called a baseline building that is dictated by a performance-based reference standard such as ASHRAE or an energy code. Despite the standards, there is room for interpretation of required inputs and assumptions for both the baseline and the proposed cases.
The ability to critically evaluate the results of an energy model or question the methodology used is important to achieving the highest and best outcome for project permitting and certification goals. This peer level evaluation can be very important when it comes to cost benefit decision-making around what it takes to comply with code or how many LEED points a project can count on that won’t need to be made up for elsewhere. This skill is more rare than one might think, and its value is still not well understood.
Material Transparency is a broad term that basically denotes what is known about the attributes of products and materials with respect to their safety, their health benefits for both manufacturing workers and ultimate users, and their sustainability measured by numerous characteristics. Even the most willing consumer cannot put their dollars behind their belief in sustainability if they don’t truly understand what their choices mean.
In the early days, material attributes revolved primarily around recycled content, local materials and volatile organic compound (VOC) content. In recent years the focus has broadened to include emissions testing, bio-based certifications, sustainably harvested wood, extended producer responsibility, environmental product declarations and material ingredient certifications. The inclusion of these considerations in green building certification systems increased demand for products that could demonstrate these characteristics.
As demand grew, so did the number of available products at a more affordable price. But with increasing demand also came “green washing”, a term that referred to claiming sustainable attributes for products without tangible proof of the veracity of those claims. And many claims remained anecdotal until research could catch up with actual metrics to back them up. So even as the awareness of these benefits has grown among consumers, the ability to differentiate valid claims from clever green washing has been much slower to develop.
Whole Building Life Cycle Assessment (WBLCA) modelingis a more sophisticated analysis of material attributes that has evolved to evaluate the implications of greenhouse gas emissions and other impacts, of materials proposed for a building over the entire building life-cycle. Currently it typically focuses on the building structure and enclosure products - materials like concrete, steel, timber, insulation, drywall and roofing. It builds on the data that follows a product’s development lifecycle from harvest or extraction through manufacturing into use and then ultimately disposal. There are several software packages available that can perform this analysis.
However, like energy modeling, a WBLCA requires a comparison between the proposed design and a baseline building. Unlike energy modeling which uses a definitive standard to establish the baseline building, there is not an accepted industry-wide standard for the proposed or baseline building in a WBLCA. This lack of standardization means that the analyses can vary widely making the comparison that results sometimes questionable. Again, it is important to be able to critically review the inputs and assumptions that govern both the baseline and proposed design cases.
WBLCAs evaluate several impact categories including global warming potential, ozone depletion, eutrophication, acidification, and non-renewable resource use. These impacts are caused by multiple chemicals in products from CFCs to nitrogen and from carbon to sulfur. For global warming potential, all greenhouse gases are converted to carbon equivalent or CO2e. This often is just shorthanded to “carbon”. Because the impacts of climate change are being felt world-wide, there is increasing focus on “carbon” to the point that it tends to focus people on carbon as if that is the only issue of concern when making decisions about material selections.
A good example of this narrow focus is mass timber which has gained momentum as an enticing alternative for mid to high-rise buildings. Wood is low in embodied carbon and a renewable resource, but the laminating process uses resins that are fairly toxic when it comes to eutrophication. The lower carbon impact of the material is perhaps offset by a higher impact on water quality, robbing our waterways of the oxygen that is needed for marine wildlife and vegetation. The fight against climate change is not just about carbon and air quality, so over-simplification carries some risk of overlooking other impacts that are important to environmental wellbeing.
Resilience addresses our ability to adapt and respond to immediate stresses as well as planning for future adversity. Many things can be resilient – people, buildings, landscapes, businesses, and economic systems. When resilience is discussed in the context of buildings, it usually means the ability of buildings to support adaptation to future challenges. It also includes protecting people and communities during a crisis. First we must understand the risks a building and its occupants might face and then design the building and operations to mitigate those risks. In recent years we have seen the realization of risks like viral transmission, wildfire smoke and extreme heat events. Resilience is gaining traction as awareness grows that these risks are not just theoretical.
But it is still difficult to spend time and money analyzing unpleasant possibilities that are specific to different regions and varied circumstances and incorporate mitigation measures in a building’s design and construction for events that may never happen. And it’s very challenging to measure the benefit of risks avoided against the capital costs of proactive adaptive measures. So the case for cost benefit can be tough to make unless regulations require it or owners or project teams have had personal experience with it.
Regulations, and the advocates that press them forward, are often the first stage in pushing the market to generate demand for new and unfamiliar products or services. Laws, codes and regulations serve many important functions including enforcing consequences for unhealthy or unsafe products and practices and incentivizing the development of varied and affordable products that are better for consumers and the environment.
Many of us remember LED light fixtures as an expensive measure rarely incorporated into building projects. That is until regulations phased out mercury lamps and incentivized the development of cheaper more plentiful LED options. Now every project and most consumers can claim 100% LEDs as a given, and as a result realize the health benefits of reduced contact with mercury and reduced electricity bills.
Commonly understood economic theory suggests that consumers will naturally move market demand toward products that are “better” in terms of affordability or quality or environmental benefit as a result of competition between suppliers. But the unfortunate reality is that varied subsidies, large conglomerates that can act like monopolies, the lack of transparent information, and limited financial resources mean that consumers are not always empowered to make choices that reflect benefits or behaviors they wish to support.
The need for regulation to help move innovation forward has not changed, but the resistance to it particularly in the area of sustainability and climate change has grown enormously in recent years. It is unfortunately still the case that when corporations can escape the consequences and the responsibility for repairing the damage they cause, they will often keep prices artificially low and profits high by passing those costs on to consumers, rather than investing in the research and development that will result in healthier products that mitigate environmental harm.
Existing buildings which represent by far the largest portion of building stock in the US have long been a hoped for target of sustainability and energy performance efforts but until recent years that sector has gotten little traction. Two factors have emerged to help change that.
ESG (Environmental Social Governance) has taken a strong hold in the real estate sector. Financial partners are keenly aware of the increased value of an asset that is resistant to energy volatility and resilient in the face of varied climate-related events. Green building certifications can support those goals and the metrics of reporting.
Regulations that focus on condition assessment, energy performance, proactive maintenance and reporting for existing buildings have been implemented in Washington and several other states to target operational carbon reduction.
Despite these factors and the growing understanding that well-maintained equipment can mean lower utility bills and better comfort, the existing building sector continues to be a tough nut to crack. Owners and property management firms do not necessarily know or understand the equipment in their buildings. The operations and maintenance data that was part of the new construction process did not necessarily end up in the hands of the staff managing or operating the building. Tenants who may bear responsibility for the maintenance of building energy systems can be reluctant to provide the data needed for assessment and reporting. Some owners would rather bear the fines for non-compliance rather than upset the relationship with their tenants.
Growing evidence and concern about climate change is a thread that runs through all of these areas. Decarbonization refers to a term, a plan and a goal that has developed out of an effort to confront the effects of greenhouse gas emissions. It can be applied across industries, corporations and their portfolios, and on individual buildings, campus, City, State and Federal levels. It derives elements from, and builds on, all of the areas discussed above. Decarbonization includes two separate areas of focus for carbon reduction - operational carbon and embodied carbon.
Operational carbon in both new and existing buildings is concerned with the sources of energy that are used to power the building’s energy systems (HVAC, lighting, hydronic) and the efficiency of the equipment used in those systems. Operational carbon is a large ongoing factor in greenhouse gas emissions from the built environment, but it is also possible to mitigate and improve performance over time in this area, as technology and the makeup of the power grid from public utilities continues to innovate and evolve. Energy modeling is directly involved in addressing these reductions. And resilience can play a role in futureproofing and adaptation.
Embodied carbon, however, is inherent in the materials that are used to construct buildings. This type of carbon is invested in the harvesting, manufacturing, transporting, installation, and ultimately the recycling or disposal of used materials. Once the materials are made, procured and used that carbon cannot be reduced. Common building materials like steel and concrete, for example, require enormous amounts of energy in their manufacture. Material transparency and whole building life cycle assessments play a key role in evaluating these materials and their impacts.
While operational carbon is fairly well understood in the market and already the focus of many regulatory energy code and ESG efforts for both new construction and existing buildings, embodied carbon is a newly emerging focus of current legislation. Materials used in the building envelope and structure – concrete, steel, timber, insulation, drywall and roofing – are typically the largest contributors to embodied carbon in a building’s construction. Given the challenging economic environment that the building industry faces with high interest rates and increasing land, labor and materials costs, this legislation faces significant headwinds.
As when we began, sustainability is complicated. It requires a nuanced understanding of the tradeoffs and cost benefits inherent in the many choices owners and project teams are called on to make. There is still no simple, one size fits all answer to the complex set of environmental and financial goals and constraints that govern building projects whether new or existing. Though two decades have increased people’s general understanding of the sustainable measures that go into green buildings, the ability to analyze options and evaluate outcomes requires a serious commitment to keeping up with changing codes, available environmentally friendly products, available software and the ins and outs of a variety of green building programs. Implementing sustainability on a practical, cost-effective basis that elevates quality of life, enhances the connection with nature and fosters community is still a full-time job.