By Adam Gordon
The residential home sector is the third largest contributor to greenhouse gas (GHG) emissions when energy use is included. As the housing market is showing signs of recovery and new home construction is beginning to increase, there is opportunity to address the emissions from residential homes with green building techniques that will have the added benefit of reduced energy costs and increased comfort.
When thinking about emissions, it’s easy to focus on the fossil fuel emissions of the transportation and industrial sectors, but they are only part of our GHG emissions. The residential sector is a large contributor of our GHG emissions and they have been increasing. According to the EPA’s February 2013 draft of Inventory of U.S Greenhouse Gas Emissions and Sinks: 1990-2011, over the twenty-one-year period from 1990 to 2011, industrial emissions have generally declined, due to factors including structural changes in the economy and energy efficiency improvements, whereas emissions from residential sources have increased. As of 2011, the residential housing sector contributed 1,227 MMtCO2-e, or roughly 17% of total emissions, when emissions from electricity use are included (Table ES-8).
These are distressing statistics but they are in line with the overall growth of the sector in the past decades and illustrate the energy inefficiency of so many of our homes. The majority of the GHG emissions produced by the residential sector are a result of energy usage. In the same way that fuel use is the primary driver of emissions from cars, energy use is the primary driver of emissions from homes. Homes use large amounts of energy for heating, cooling, lighting, and household appliances. While some gains can be achieved by purchasing energy-efficient lighting fixtures and appliances, others such as heating and cooling efficiencies are best integrated at the time of construction (or during retrofits) and have the dual benefits of reducing utility bills and making homes more comfortable. Many simple green home building techniques are outlined in the LEED for Homes and Energy Star certification programs and they provide information on the breadth of energy efficiency techniques available to new homes. These techniques allow homes to reduce their energy consumption and energy bills while still effectively meeting their heating, cooling and other needs.
Increasing the energy efficiency of new buildings does not require any new technologies or major changes to production. Existing buildings can be retrofit to increase their energy efficiency, however it is important to apply green building techniques to new home constructions in particular because they face the same energy challenges as older buildings and can be built from the start with greater efficiency. The technologies and methods to build energy efficient homes exist today and it is unfortunate to think that many new homes are being built without them.
Making energy efficiency a key feature of new homes can be an important part of our strategy to reduce our impact on the climate. As our population grows and more and more people need to be housed, the traditional inefficient ways of meeting our electricity needs will not be sufficient. If new housing is not made to be more energy efficient, any reductions produced in existing homes will be offset by the additional sector growth. We need to see an absolute reduction in GHG emissions from the residential sector and not simply a relative reduction. Energy efficiency is the most effective tool to make those sector reductions and it brings the issue home by allowing homeowners to benefit from and meaningfully impact mitigation efforts.
Adam Gordon is an intern with the Columbia Climate Center and a Master of Science student in Sustainability Management with the Earth Institute, Columbia University. He is a co-founder of NYCOMPOST and a consultant with Farmhouse Solutions.