What has one of the biggest impacts on city sustainability and on residents’ health and quality of life? The answer is: How cities manage the sun and rain that fall on them.
Integrating and optimizing the built environment offers a valuable opportunity for urban planners and architects to significantly reduce the human environmental footprint by mapping and integrating human needs. Some cities have already established programs supporting adoption of cool roofs, solar PV, or reflective pavements, while others promote expansion of green roofs and trees. Evolving rating systems are challenging developers do more than just meet higher standards — they’re attempting to address issues such as the impact of fires on entire communities and lifestyles through building for resiliency.
Carbon emissions are a product of four factors: population, gross domestic product (GDP) per capita, energy intensity of the economy (per unit of GDP), and carbon intensity of that energy. We need deep energy efficiency in our buildings as part of a larger strategy to limit global warming to well below 2 degrees Celsius, to see global carbon emissions peak by 2020, and to assess a 50% per decade decrease every decade after. A common way of thinking about buildings and climate action is through a “net zero” lens. This means that, over the course of a year, a building generates as much renewable energy on site as it consumes.
New tools and frameworks offer architects and urban planners innovative ways to improve how their buildings perform during natural disasters like earthquakes and increasingly extreme weather events caused by climate change. The RELi resilience action list and credit catalog, the REDi Resilience-based Earthquake Design Initiative, and the American Red Cross Ready Rating program offer rating systems specifically for building resilience measures.
Long-Term Effects of Limited, Fragmented Urban Planning
Cities can increase resilience, improve health and comfort, expand jobs, and slow global warming through smart surface strategies. That’s the driving message of the “Delivering Urban Resilience” report from the Capital E Group. They say that, conversely, when cities neglect urban sustainability measures, the consequences are greatest in low-income areas. These physical areas are characterized by little greenery and dark impervious surfaces and result in excess summer heat and air pollution, excess respiratory illness, heat stress, and high health costs. Deployment of solutions at scale in low-income areas can address systemic inequity in urban quality of life from excess heat, degraded air quality, and less greenery than in wealthier urban areas.
Example of urban sustainability measures are cool and green roofs. For example, Denver’s Green Roof Initiative requires any building with a gross floor area of 25,000 square feet or greater to include a green roof, also known as a living roof, covered by vegetation, solar panel installations, or a combination of both. The Initiative supports important environmental implications to mitigate Denver’s growing ozone and pollution output.
The “Delivering Urban Resilience” report points out how smart surface strategies are both cost-effective and essential for city resilience, can help protect our citizens, and support our cities to remain livable in a warming world. As deployment scales up, the urban cooling benefits also grow proportionally, reducing energy bills and smog, and improving health and livability. Low-income areas can achieve large gains in health, comfort and resilience, thus reducing energy bills and mitigating climate change with policies and solutions.
Building for Resilience with 100% Clean Renewable Energy and Green Materials
A Zero Net Energy (ZNE) structure produces as much clean, renewable energy as it uses over the course of a year through a highly efficient building and a rooftop photovoltaic (PV) solar energy array. An efficient, all-electric community reduces risks and can be powered by 100% clean, renewable energy that is locally produced and supports the local economy. A ZNE building has lower energy bills, comfortable temperatures even in extreme weather, ability to be independent during power outages, and can alleviate stress on the community’s electric grid.
When green elements are part of the regular design process and accommodated within a project’s budget, costs are about equivalent to traditional construction. To balance expenditures, urban planners and architects prioritize cost-effective performance and comfort strategies over more superficial, expensive ones.
Products are resilient if their manufacturers eliminate toxic chemical ingredients or reduce embodied energy. Insulation, paints, flooring, and adhesives all have green options. Structures and landscapes are less vulnerable to fire spread when their roof venting is designed to avoid spark intrusion, exterior materials are chosen for their fire-resistance qualities, and fuel in the surrounding landscape is minimized.
LEED is Essential to Building for Resiliency
LEED, or Leadership in Energy and Environmental Design, has become a very important standard for the US and the world, helping to define the baseline of green building and using its power in the market to evolve its standards over time. According to the 2017 National Green Building Adoption Index, LEED-certified buildings only account for 4.7% of the commercial office buildings across the 30 largest US office markets. LEED platinum certification is the highest level rating in the world’s most widely recognized green building rating system.
While LEED has raised expectations for green building in general, there are also a growing suite of topic-specific sustainability rating systems for health, wellness, energy-efficiency, and — ta da! — resilience. LEED v4 is the newest version of LEED. It focuses on:
- materials, so constituents in the building industry obtain a better understanding of their contents and the effect those material components have on human health and the environment;
- a stronger, performance-based approach to indoor environmental quality for better occupant comfort;
- the benefits of smart grid thinking with a credit that rewards projects for participating in demand response programs; and,
- a clearer picture of water efficiency by evaluating total building water use.
The time is now to strategically approach green building technology and energy efficiency by optimizing planning around people, nature, and essential needs. Economic and social growth that is supported by a healthy environment and sustainable resource management is the key to a future in which self-sustaining ecosystems can evolve and adapt over time. Advanced technology applications like artificial intelligence and smart systems can minimize consumption of natural resources, balance the whole ecosystem, and assure economic and social prosperity in a healthy environment. Add in datasets and experience, and urban planners and architects have a toolkit to significantly reduce the human environmental footprint by mapping and integrating human needs.
Building for resiliency requires a systematic, long-term approach. Even in an era in which solar panels are becoming more affordable, we need to consider a repertoire of energy efficiency strategies for urban buildings. Solar panels are one ingredient in a larger equation of building for resiliency. In fact, building energy efficiency has never been more relevant to climate action than it is today.