Homebuilders Providing Crucial Defense Against Climate Change

From weather-resilient homes to power systems, builders deliver stronger homes

By PATRICK DUFFY

For many years now, the nation’s homebuilders have been at the forefront of preparing for ongoing climate change, whether in the form

of offering rooftop solar panels, improved energy efficiency, or creative methods for channeling and removing water from stronger storms. However, in addition to these voluntary advances to meet market demand, state and local governments are increasingly likely to require building even more energy-efficient and resilient homes, such as California’s Title 24 rules scheduled to start in January 2020.

Starting that month, every new single-family home or multifamily unit in a building of three or fewer stories must include access to solar panels, which the state’s Energy Commission has estimated will save an average of $19,000 over a 30-year period, but also add approximately $8,400 to the cost of the of a single-family unit. According to a NAHB study published earlier this year, given that every $1,000 increase in cost makes a new home in California home unaffordable to nearly 9,900 households, this $8,400 increase could make it harder for over 83,000 households to buy a median-priced unit.

Still, homeowners can often lease the panels through a third party and receive a 20 percent discount on their electrical bill, or enter into a purchase agreement from community-shared solar farms, which could, at least according to the California Building Industry Association, theoretically lower that cost to $1,200 through economics of scale. The new mandate also allows builders to partner with utilities to bring in solar-only energy, which could lower the price even further.

However, renewable sources of energy such as solar panels are only part of the climate equation. Growing threats of wildfire have also focused attention on the most suitable places to build new housing, especially as urban footprints expand into undeveloped areas with years of pent-up natural fuel. Although much of the threat can be minimized

with more aggressive management of these natural spaces, some architects and builders are creating or remodeling existing structures to better resist fires.

These adaptations can include eliminating vents or roof overhangs where embers can land, and using roofing rated Class A for fire resistance, seamless stucco walls, aluminum doors and windows, steel exterior stairs, concrete pavers or tiles, and denser hardwoods which are more resistant to fire. Inside, choosing tempered glass can withstand temperatures up to 450 degrees before breaking.

Other necessary adaptations will be required for storms which are stronger, dump larger amounts of rain in shorter periods of time, and threaten low-lying coastal communities with water surges and higher tides. Following Hurricane Sandy in 2012 and Hurricane Harvey in 2017, low-lying communities around New York City and Houston began elevating homes as the easiest way to avoid future floods. In Harris County, Texas, which surrounds but does not include Houston, new rules enacted in late 2017 will require builders in some areas to raise new homes up to eight feet higher than before. But this is an exception, as the Insurance Institute for Business and Home Safety recommends typically elevating homes three feet above the ground in 100-year floodplains.

Besides potential damage from fire and floods, homes in the future will also have to contend with more heat and stronger winds. Fortunately, there are already homes being built to address these vulnerabilities, such as “La House,” which was built in 2008 at Louisiana State University at Baton Rouge by the campus’ Agricultural Center to withstand most floods, 130-mile-per-hour winds, lashing rain, flying debris, hail, and even a deep freeze. The model home, which is used as a type of museum to showcase high-performance building options, is elevated several feet using three different techniques, and also features waterproof insulation.

However, as the building industry will increasingly be asked to provide more weather-resilient housing, given the impact of the built environment on climate, they’ll also be pressured to make the homebuilding process less carbon intensive. According to the Department of Energy, U.S. buildings account for 39 percent of primary energy consumption, and 72 percent of all electricity consumed domestically. Including the “embodied energy” used to create our structures, the United Nations calculates that our buildings contribute nearly half of total U.S. emissions. Consequently, adapting to a harsher climate

is mostly an issue of how we design the structures in which we live, work and play, which is why continued innovation in the building industry is so critical. In a rapidly urbanizing world in which the total building stock is expected to double by 2060, preparing to meet net-zero-carbon standards will certainly remain an ongoing challenge.

Patrick Duffy is a Principal with MetroIntelligence and contributes to BuilderBytes. He may be reached at pduffy@metrointel.com or 310-666-8288.

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