Between now and 2030, the global population is projected to grow by more than 500 million people. Just meeting the needs of this population increase will necessitate adding approximately 188 million housing units, 2.2 million primary schools, 2.7 million secondary schools, hospitals to accommodate 1.7 million beds, and associated facilities and infrastructure.
How we plan, design, construct, renovate, and repurpose the global built environment over the next decade to meet these needs may determine the fate and well-being of life on the planet. We must deliver an architecture and development pattern that mitigates carbon; supports adaptation; and ties to local conditions, human health, ecological restoration, and energy and water availability and security. This is the message we are taking to COP27 in Sharm El-Sheikh, Egypt, this fall.
Resilient strategies are used globally, many contemporary, others derived from vernacular architecture’s strong relationship to climate and natural processes. Many of these techniques—some key ones follow—have been aggregated into a set of accessible guidelines at various scales that can be implemented immediately. More options are available through Architect 2030’s ree, open-access 2030 Palette database. They support an approach to the natural and built environment that dramatically reduces or eliminates greenhouse gas emissions, addresses climate adaptation and resilience, and offers the potential for an accessible and inexhaustible supply of renewable energy.
The following outlines some of the key strategies in various regions and conditions that can be implemented immediately. For more detail on these and many other strategies see the 2030 Palette.
Transit-oriented development. Establishing TODs within ¼ to ½ mile walking distance of transit with a mix of housing and commercial areas encourages walking and bicycling, while reducing infrastructure costs and emissions.
New growth areas. Planning for growth by identifying and establishing environmentally suitable new growth areas, adjacent to or within cities and located along existing or planned transit lines, will limit urban sprawl, which can avoid damaging farmland and other environmental assets.
Habitat corridors. Mapped and protected habitat corridors preserve the ability of species to migrate successfully while enhancing the integrity of sensitive ecosystems.
Urban infill and retrofit. Infill, repurposing, and redeveloping areas and buildings within walking distance to transit and district centers reduces sprawl, infrastructure, and growth pressure on rural areas and open space.
Street networks. Planning short block lengths and well-connected, dense street networks encourage bicycling, makes walking more interesting, increases foot traffic for local businesses, reduces vehicle traffic and enhances traffic flow, and makes destinations and transit stations more accessible.
Heat-island mitigation. Increasing the solar reflectance, tree canopy, and vegetative cover in urban areas cools outdoor temperatures while reducing air pollution and energy consumption.
Water catchment and storage. Catchment systems store rainwater and can provide a clean, free water source when treated and disinfected.
Cool roofs. In hot climates or seasons, a light-colored roof that reflects sunlight and emits heat efficiently will remain cooler and reduce heat transferred into a building.
Double roofs. In hot climates, a structure located just above the roof shades the roof and allows warm air buildup between the roof and structure to escape, reducing indoor cooling requirements. When extended, the roofline can shade exterior walls and create shaded outdoor living spaces.
Elevated structures. When designing in coastal or flood-prone areas, it is essential to plan for possible inundation by elevating structures, or leaving space for water flow without compromising the structural integrity of buildings and infrastructure.
Direct-gain passive heating. In cold climates, equator-facing solar glazing coupled with adequate thermal mass will heat a space in winter over a 24-hour period.
Solar shading. During warm summer months, overhangs block direct sunlight from equator-facing solar glazing, reducing indoor cooling loads.
Side daylighting. Exterior wall glazing provides interior task-daylighting levels at a depth of 1.5 to 2 times the height of the opening. Adding a light shelf can increase the daylight depth to 2.5 times the height of the opening.
Cross ventilation. Ventilate and/or cool buildings by locating window openings perpendicular to prevailing winds and on opposite sides of a space or building. Maintain an unobstructed path between inlet and outlet openings for adequate airflow.
Night-vent cooling. In dry climates with cool nighttime temperatures, use cool night air to flush heat from a space and cool interior walls and floors, keeping a space cool during the daytime.
Designing with wood. Specify reclaimed wood or wood from well-managed forests that encourage protecting habitats and water quality; local harvesting; air-drying lumber; and not harvesting lumber from old-growth forests.
Designing with concrete. Reducing the carbon footprint of concrete includes (but is not limited to):
- designing for structural efficiency (not using more concrete than necessary)
- substituting supplementary cementitious materials from non-fossil fuel based sources
- utilizing carbon sequestration (CO2 injection)
- using larger aggregate (e.g., 1” vs ¾” coarse aggregate) where appropriate
- specifying Portland Limestone Cement over typical Portland cement where locally available
- reducing the weight of slabs to reduce the size of columns and foundations
Designing with steel. Design for material efficiency to reduce the amount of steel. Specify steel from electric arc furnaces to reduce steel emissions, because EAFs use high levels of recycled material and can be powered by renewables. We have the design and planning strategies to effectively address the climate crisis. We must accelerate their application to ensure a habitable planet.
We have the design and planning strategies to effectively address the climate crisis. We must now accelerate their application to ensure a habitable planet.
This article first appeared in the September 2022 issue of ARCHITECT.
Read more: Why sustainable practices must extend beyond the building and into the exterior built environment. | Are we moving towards zero-waste offices? | Architecture 2030 senior fellow Carl Elefante on why architects should focus on eliminating emissions from existing buildings.