Recap

In Rethinking Density, Part One, I provided evidence that most Americans of prime working age (25-54) want to live in detached houses in low-density residential areas.  Americans also prefer community and residential features such as limited street traffic, open space options nearby, large back yards and off-street parking. They especially want to live in quiet neighborhoods that are safe for walking and for kids to play outdoors.

In A Climate-Friendly Alternative to High-Rise Urban Density, I summarized studies that found high-rise living to be a net negative for most people, especially families and children, and regardless of culture, nationality, or aesthetic traditions. For example, compared with other housing forms, high-rise apartments are associated with less social cohesion, more crime, more suicide, and suboptimal conditions for children’s emotional, cognitive and behavioral development. While per household GHG emissions tend to be much lower in tall apartments than in other types of housing, is that worth more than all the negatives? 

A possible climate-friendly alternative to high-rise urban density would be a mix of smaller apartment buildings and single-family homes, ideally in walkable communities or at most a short drive away from frequent destinations. Of course, this is all assuming the buildings, homes, communities and modes of transportation can achieve meaningful reductions in GHG emissions through technology fixes and changes in human behavior.

In Summer Reading: Ways to Reduce Greenhouse Gas Emissions in Home Construction,  I summarized research on ways to reduce emissions in the construction of single-family homes. Recommendations included: increase use of building materials made of wood, avoid concrete basements, minimize infiltration (air leakage), properly insulate, install electrical heating systems (e.g., solar-powered heat pumps), transition to renewable electricity (e.g., rooftop PV), and build smaller houses (e.g., reduce average floor area of new homes by 15% by 2050).

—

Ten Features of Climate-Friendly Single-Family Homes and Community Context

  1. Approaching net-zero* electrical grid with home-based renewable energy backup

  2. Electrical heating and cooling systems, such as heat pumps** (ideally solar-powered)

  3. Well-insulated and weatherized homes with minimal air leakage

  4. Places to gather, visit or shop within walking distance or short drive

  5. Residential areas connected by public transit to major employment hubs (if applicable)

  6. All homes have charging stations for electric vehicles

  7. Smaller homes in new developments (target: 15% less floor area than current average).

  8. Extensive sidewalks within and beyond residential community

  9. Tree-lined streets and financial incentives to plant trees on property to increase shade

  10. Smart appliances (e.g., thermostats) to reduce energy usage

—

* Net zero emissions means achieving a balance between the greenhouse gases (GHG) put into the atmosphere and those taken out.

** A heat pump is an air conditioner running in reverse. Working at temperatures as low as minus 5 degrees Fahrenheit, the pump takes cold air from outside and produces warm air inside. It runs on electricity but is three times more efficient than the space heater under your desk. Greater efficiency translates to lower costs but the real savings come from using solar PV, which is cheaper than grid electricity.