California is the poster child for efforts to lower carbon emissions. It’s notable that, in a report from Stanford on reaching carbon neutrality in California, the authors declare – “California can’t build its way out of this – Existing buildings must be retrofitted.”
When it comes to lowering greenhouse gas emissions, this is true in every state. Residential and commercial buildings are responsible for about 40% of all energy consumption in the U.S. In fact, our homes and commercial buildings use more energy than cars, planes, trucks, and every form of transportation combined.
While newer homes are built to more energy efficient building codes, there are plenty of older homes that waste energy. Up to 40% of the energy used is wasted when heat or air conditioning escape through leaks, gaps, and holes in a building.
Not only is the energy waste greater in older homes, but there’s far more of them. California adds about 850,000 units of housing a year, compared to 14 million existing homes.
The best way to have an impact on building carbon emissions is to secure the building envelope. In other words, seal those leaks, gaps, and holes so air conditioning or heat cannot escape. The Stanford report notes that “a mere 5% reduction in energy use from legacy homes would be the same as driving energy use from new homes to zero” and one way “to reduce the need for heating and cooling [is] by improving the thermal envelope.”
As policymakers look for ways to make a real dent in greenhouse gas emissions, tax credits or programs to retrofit homes to create a strong building envelope have a great payoff.