Green Building and Sustainability Brief

Sustainability and Affordable Housing Development

Developers have an important opportunity and responsibility to ensure that the physical condition of a person’s home, as well as the physical and social environment in which the home is located, is of high quality. This brief will provide you with the background, guidance, and tools to incorporate sustainability in your development goals.

What is sustainability?

Broadly, sustainability is the ability to meet your own needs without compromising the ability of future generations to meet their own needs. In the realm of affordable housing development, sustainability is primarily discussed as “green building.”

When you see or hear the term “green building,” you may think about environmentally friendly products, recycled materials, or energy efficiency. In the early 2000s, green building was more narrowly defined around singular components of sustainability in a building’s life cycle like energy use, water use, indoor environmental quality, material selection, and building site impacts. Today, green building has expanded to contain a comprehensive set of building standards that provide benefits to resident health, resource conservation, and land use. The green-building movement has also begun to reframe the conversation about building operations, maintenance costs, and the positive impacts of green building—affordable housing is not truly affordable for residents or developers if the construction costs are cheap, but the operational costs are high.

In addition, the impacts of the COVID-19 pandemic, the changing climate, and widespread housing affordability challenges across the United States have shown that creating affordable green housing is more critical now than ever. However, healthy living environments with affordable utility expenses are fundamental for resilient communities, no matter what is happening or changing in the world.

Why should developers practice green building?

Economic Benefits

Green building is economically advantageous for developers, residents, and the communities in which they work. First, green building is cost-efficient as energy efficiency results in lower maintenance costs. According to a report from the U.S. Department of Energy, green-certified buildings have reported almost 20 percent lower maintenance costs than typical commercial buildings.[28] In terms of utilities, green rental developments save nearly $5,000 per year on owner-paid utility costs when compared to non-green developments.4 In addition, the return on investment for green buildings is high. According to the U.S. Green Building Council, owners of green buildings reported that their return on investment improved by an average of 19.2 percent for existing green-building projects and an average of 9.9 percent for new projects.[29]

Residents also benefit from green-building cost savings. A study completed by Southface and the Virginia Center for Housing Research found that families residing in green developments save nearly $8 per month/$96 per year, and older adults save more than $10 per month/$122 per year when compared to non-green developments.[30] The average household in Colorado dedicates about 2 percent of the household’s income for energy expenditures, but many households have expenditures that can exceed 10 percent, causing them to be energy-impoverished.[31] This can be particularly burdensome for low- to moderate-income communities. So, having lower and more predictable utility expenses allows residents to not have to choose between paying their utilities or rent or putting food on the table, ensuring a holistic housing affordability strategy.

Health Benefits

Green buildings improve the health, safety, and well-being of people. Clean air and water and protection from environmental toxins are important for preventing asthma, respiratory allergies, depression, fatigue, and general stress—all symptoms of “sick-building syndrome” or SBS.[32] Adults who live in green units report fewer SBS symptoms than those living in traditional units, and asthmatic children living in green units are less likely to experience asthma-related symptoms, attacks, hospital visits, or missed school days.[33] Additionally, the National Center for Healthy Housing found that asthmatic residents of green affordable housing units in Seattle, Washington, saw 63 percent more symptom-free days than they did in their previous homes.[34]

Green building can also include healthy living considerations such as universal design, which ensures homes are accessible to people with a wide range of abilities and other characteristics but is especially helpful for the older adult population. For example, universal design promotes aging-in-place features to help prevent worsening health issues that can lead to increased isolation and premature moves into assisted living or nursing facilities.[35] Affordable housing that supports aging adults’ ability to live an independent, active lifestyle is essential.

Environmental Benefits

Green building protects the health of our natural environment and is integral to preserving Colorado’s way of life in the face of a changing climate. A statewide transition to clean energy underpins Colorado’s commitment to climate action as the state recognizes its vulnerability to these impacts—increased risks of catastrophic wildfires, greater likelihood of droughts, increased flood risks, and loss of alpine ecosystems.[36]

The U.S. Department of Energy reviewed 22 LEED-certified green buildings and found that carbon dioxide emissions were 34 percent lower, they consumed 25 percent less energy and 11 percent less water, and diverted more than 80 million tons of material waste from landfills. Increased energy efficiency can lower greenhouse gas emissions and other air pollutants by decreasing consumption of fossil-fuel-based energy, which accounts for 37 percent of the country’s carbon dioxide emissions.[37] For example, an ENERGY STAR^TM certified new home can reduce greenhouse gas emissions by up to 2 metric tons of carbon dioxide a year.

Other notable environmental benefits of green building are better stormwater management and more thoughtful site selection. Green building encompasses a variety of water management practices, such as vegetated rooftops, roadside plantings, and absorbent gardens that capture, filter, and reduce stormwater, reducing the amount of flooding and polluted runoff that reaches sewers, streams, rivers, lakes, and oceans. Also, by avoiding building on sensitive lands, project teams can protect against potentially harmful flooding and play an active role in preserving the beautiful environments Colorado is known for.

Economic prosperity, improved resident health, and environmental stewardship each have their own set of advantages, that when integrated during the development process, combine for the greatest impact on project performance and the ability to successfully provide affordable, decent, and accessible housing to Coloradans.

Going beyond building codes

The sustainable-development and green-building practices described later in this brief encourage innovation in the design and construction of affordable housing beyond the many local building codes and standards across the state of Colorado. Building codes are designed with the primary goal of preventing major building failures. While they may incorporate some measures to promote the creation of healthy and sustainable living environments, they do not always integrate key green-building standards and approaches. Going beyond the code may seem daunting, but true sustainability can be implemented and achieved universally regardless of the development model under the guidance of existing green-building standards and certification programs. However, due to the wide variation in building codes across jurisdictions in Colorado, ensure that the following green-building standards and measures are code-compliant before adopting any to your project.

Green Building Standards and Certification Programs

Housing construction, occupancy, renovation, and demolition use energy, water, and raw materials; generate waste; and emit harmful atmospheric emissions and pollutants. Because of these direct and indirect impacts on the environment, green building standards and certifications have established a set of formally recognized design and construction practices that mitigate harm to the natural environment and improve the health of building occupants. These standards and certifications provide architects, builders, and developers with options for implementing green building in a variety of ways over the course of a project’s life cycle. They also provide resources and expert guidance through the green-building process to ensure you meet your goals without unintended consequences.

How do green building standards and certification programs work?

Think of green-building standards and certification programs as an assessment, measurement, and verification tool. They are used to judge a building’s or construction project’s performance from a sustainability and environmental perspective. Once assessed, the green-building standard or certification confirms that the product meets a particular standard and offers a true environmental and social benefit.

They can also be thought of as recipes or checklists that provide the building requirements or standards to be followed if a particular project wants to be green. If architects, builders, or developers add the proper ingredients to their project, they will achieve a building that passes the certification test.

Top green building standards and certifications to know about

Enterprise Green Communities Criteria.[38] The Enterprise Green Communities Criteria (EGCC) is the only national green-building criteria and certification program designed exclusively for affordable housing. It is a clear, cost-effective framework for all affordable housing development types and is aligned with the importance of addressing the world’s changing climate, improving the health and opportunities of residents, and creating long-term economic viability. In addition to EGCC’s two levels of certification (Enterprise Green Communities Certification and Enterprise Green Communities Certification Plus), Enterprise Green Communities offers a dual certification with the International WELL Building Institute.

The criteria are presented as a checklist with eight different categories:

• Integrative design

• Location and neighborhood fabric

• Site improvements

• Water

• Operating energy

• Materials

• Healthy living environment

• Operations, maintenance, and resident engagement

Within each category is a list of requirements and recommendations that share how an affordable housing development team should plan to achieve the goals set by each criterion. In order to receive Enterprise Green Communities Certification, a project must meet all of EGCC’s mandatory measures based on the project’s construction type.

LEED v4.1 (Leadership in Energy and Environmental Design).[39] LEED is the world’s leading green-building project and performance management system.13 LEED’s comprehensive set of building standards helps development professionals focus on addressing energy efficiency, water conservation, site selection, material selection, day lighting, and waste reduction.

There are a variety of different LEED rating systems to choose from depending on your project type and project goals: building design and construction, interior design and construction, operations and maintenance, residential, cities and communities, and recertification. Like the Enterprise Green Communities Criteria, LEED v4.1 (the latest version of the rating system as of this guide’s publication) is presented in a scorecard format. The scorecard contains credits that buildings can earn in nine different categories[40]:

• Integrative process

• Location and transportation

• Sustainable sites

• Water efficiency

• Energy and atmosphere

• Materials and resources

• Indoor environmental quality

• Innovation

• Regional priority

As a credit-based rating system, LEED certification is divided into four tiers listed in order from lowest to highest: certified, silver, gold, and platinum. Regardless of the tier achieved, all projects seeking LEED certification must meet the mandatory prerequisites.[41]

ICC 700 National Green Building Standard.[42] The ICC 700 National Green Building Standard (NGBS/the Standard) is the first residential green-building standard to receive approval from the American National Standards Institute (ANSI). It provides architects, builders, and developers with a flexible program that goes beyond minimum building requirements to design and construct homes that are sustainable, cost-effective, and geographically appropriate.

The Standard consists of a set of mandatory requirements, plus additional points that are awarded on a point system. The point system for green buildings is divided into six categories:

• Lot design, preparation, and development

• Resource efficiency

• Energy efficiency

• Water efficiency

• Indoor environmental quality

• Operation, maintenance, and building-owner education

Like LEED, the Standard certifies green buildings according to four rating levels, listed in order from lowest to highest: bronze, silver, gold, and emerald. The rating level you receive is based on the number of points your project earns. The four rating levels give developers the flexibility to integrate sustainability and high-performance standards into their project at a level appropriate for their business model, customer base, and local housing market.

Additional programs focusing on deeper energy savings

Zero Energy Ready Homes.[43] Zero Energy Ready Homes is a program by the U.S. Department of Energy that ensures the highest level of home energy savings, comfort, health, and durability through a set of rigorous requirements. The program recognizes architects, builders, and developers for their leadership in increasing energy efficiency, improving indoor air quality, and making homes zero-energy ready. A major benefit of Zero Energy Ready Homes is that they are at least 40-50 percent more energy efficient than a typical new home.

Passive House Institute.[44] Passive House is the world’s leading standard in energy-efficient construction and stands for quality, comfort, and energy efficiency. Passive Houses require very little energy to achieve a comfortable indoor temperature year-round, surpassing traditional heating and air conditioning systems. Buildings, building components, and professionals can all become Passive-House-certified.

Passive House Institute US+.[45] The Passive House Institute US+ certification program is the leading passive-building certification program in North America. In addition to housing, passive building works for schools, offices, hotels, multifamily housing, and high rises. Because of the careful design strategy and building technology behind passive housing, the following long-term benefits can be enjoyed: indoor comfort even in extreme weather conditions, excellent indoor air quality, extreme resilience, and an easy path to achieving net-zero and net-positive buildings.

The value of third-party certification

Is it worthwhile to go through the process to certify your green-building project or should you build it according to the standard without the actual certification?

There are a variety of benefits to pursuing third-party certifications like the Enterprise Green Communities Certification, LEED v4.1 Certification, or National Green Building Standard (NGBS) Certification. Each of these programs are nationally or globally recognized symbols of sustainability achievement and leadership, and millions of people are already living, working, and learning in sustainably certified buildings around the world.

In some markets, certification allows you to gain a competitive edge and attract both residential and commercial tenants. Certified apartment buildings may command higher rents and lease faster than traditional apartment buildings. Also, vacancy rates for green buildings are estimated to be 4 percent lower than non-green properties.[46] Certification also guarantees economic, health, and environmental benefits by providing proof that your housing development is truly green. Every NGBS Green Certified home is inspected in person at least twice by a NGBS Green verifier to ensure that each sustainable practice, product, and technology was installed or implemented correctly and is operating as intended.[47]

On the other hand, there are some disadvantages to pursuing green-building certification. Most programs require additional costs to certify a project, like registration fees, document submission fees, third-party inspection fees, and certification fees once the project is approved. Green building also requires project teams to work differently and more collaboratively than traditional projects because of the learning curve involved with becoming knowledgeable about planning for and implementing green-building certification standards. If your project team is new to green building, work with an experienced consultant to help walk you through the process.

Whether an affordable housing development is certified or not, green-building design and construction is imperative as we seek to create affordable, decent, and accessible housing in a world whose resources are increasingly depleted.

Practicing Green Building in Development

Green-building practices can be implemented at any phase of the development process. If you’re wondering where to begin, here are considerations to make on your journey to supplying sustainable affordable housing.

Stage 1. Committing to sustainability success

• Assess your baselines using qualitative and quantitative data from your previous projects, such as your portfolio’s average energy and water consumption, operating expenses, and the common health needs of your residents to inform new green-building goals discerned through pursuing green certification or not.

• Engage community members and project stakeholders about the potential for incorporating a green-building lens into the work to identify key opportunities to do so.

• Define and communicate the roles and responsibilities of your project team. Hire a green-building consultant. Architects can also fill this role if they specialize in sustainable design or green-certified projects. Look for utility rebates and other incentives you may qualify for.

• Explore if green certification is a good fit for your development by weighing the pros and cons based on your project’s construction type. Some construction types, such as limited-scope rehabilitation or acquisition-only projects, have limitations that make green-building requirements especially challenging to meet.

• Research green-building standards and certification programs appropriate and helpful to your development goals.

• Be explicit about the alignment of the economic, health, and environmental benefits with broader community and environmental needs so that all project team members have a clear and common understanding of your project commitments, priorities, and goals with respect to green building.

• Choose a location that offers transportation options and a variety of nearby destinations to make it easier for people to walk, bike, and take public transit.[48] Is the site well-connected to amenities like employment opportunities, shops, restaurants, schools, and other resources?

• Build on or near already-developed sites in order to save money and resources by using existing infrastructure. Reusing and renovating existing structures, historic buildings, vacant properties, and Brownfields can help spur the local economy and strengthen community character.

• Conserve and protect any ecologically sensitive site features, including but not limited to, floodplains, aquatic ecosystems (e.g., wetlands and deep-water habitats), habitat for threatened or endangered species, and prime farmland.

• Conduct site assessments to create and implement a stormwater pollution protection plan or erosion and sedimentation control plan to keep water systems from harm.

Stage 2. Land and site planning

Other considerations may include solar access, reduced site paving, saving natural plants and areas, and site layouts sensitive to elements like sun and wind.[49]

Stage 3. Design

• Design wall assemblies to incorporate passive heating and cooling systems like an open rainscreen.[50]

• Specify materials and products with the lowest carbon footprint. They could be locally sourced, sustainably harvested, or recycled materials.

• Specify water-conserving fixtures to reduce total indoor water consumption like dual-flush toilets and water-efficient shower heads, faucets, dishwashers, and clothes washers.

• Lower the need for artificial light by harvesting natural light through the building’s design. For example, large, glazed openings or picture windows allow an abundance of natural light to enter the building during the day while providing views to the outside landscape.

• Incorporate universal-design features based on your expected resident population.

Other considerations may include avoiding excessive building size, acoustical considerations, avoiding attached garages, cladding and roofing, mechanical equipment selection, air-sealing materials, and systems.

Stage 4. Construction

• Adopt lean construction principles to maximize efficiency, reduce waste, and optimize the construction process at every step.[51] For example, schedule materials to be delivered to the job site “just in time” (at the point in construction when they are needed) to avoid keeping materials outside before installation. Also, order materials based on actual need rather than a need that is estimated earlier in the project when details are less clear.

• Employ design and management techniques that reduce or eliminate stormwater runoff. Reduce stormwater runoff and pollution of local waterways caused by construction debris by controlling erosion and sedimentation.

• Reduce, reuse, and recycle construction debris by promoting and searching for opportunities to incorporate recycled materials into construction products. Prioritize the reduction of building-related wastes through efficient jobsite practices.

• Use newer and more fuel-efficient equipment to burn less fuel.[52]

• Reduce waste as much as possible through streamlined offsite construction processes like modular or prefabricated construction.

• Go digital and replace paper blueprints, drawings, and specifications with construction management software.

Other considerations may include changes that affect energy consumption or otherwise compromise green-building objectives, hazardous-waste disposal, reduced site disturbance, and noise pollution.

Stage 5. Post-construction

• Provide orientations, resident manuals, and other materials to help residents and property managers better understand the building features.

• Provide feedback to residents on energy and water use to help achieve resource conservation goals.[53] Use benchmarking tools to engage in energy and water tracking to assess performance, establish baselines, and set performance-improvement goals.

• Incorporate preventive rather than reactive maintenance on all building systems to ensure reliable service. Ensure building maintenance staff is conducting preventive maintenance on all building exhaust systems to ensure indoor air quality.

• Enforce smoke-free policies in all common areas.

Other considerations may include proper operation of green-building elements and systems, home energy rating/ENERGY STAR^TM approval, homebuyer and renter education, and operating manual.