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Refurbished vs. New House Energy Efficiency

Posted April 10th, 2008 by TimJFowler
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Rehabbed Historic House

While the real estate market is currently in a flat spin, housing is still a basic need. Choosing a home may be the biggest way you can affect your personal CO2 footprint. If a yurt doesn't meet your housing needs there are other low CO2 options. If you are choosing between a new and a used home, which is the better option? The answer, of course, is that "it depends".

I live in a house that was built in 1971. As it was built before the 1973 Oil / Energy Crisis, it is not very energy efficient. While the water heater, furnace and windows are newer, more energy efficient models, the overall structure could be much better. Would it be wiser to start with a new house, or does it make sense to refurbish this older home? Apart from the upfront costs of building a new, 'green' house, there are other arguments to be made for rehabbing an existing home.

A new study carried out by the Empty Homes Agency charity in Great Britain, suggests that housing developers have overestimated the amount of overall CO2 saved by building energy-efficient homes. The New Tricks With Old Bricks study compared the CO2 given off in building new homes and creating new homes through refurbishing old properties.

The New Tricks With Old Bricks - Key Findings are:

  • Reusing empty homes could make an initial saving of 35 tonnes of carbon dioxide (CO2) per property by removing the need for the energy locked into new build materials and construction.
  • Over a 50-year period, this means there almost no difference in the average emissions of new compared with refurbished housing.
  • Carbon dioxide (CO2) emissions from new homes fall into two distinct sources: “Embodied” CO2 given off during the housebuilding process, and “operational” CO2 given off from normal energy use in the house once it is occupied.
  • The new homes each gave off 50 tonnes of embodied CO2. The refurbished homes each gave off 15 tonnes.
  • Well-insulated new homes eventually make up for their high embodied energy costs through lower operational CO2 but it takes several decades - in most cases more than 50 years.
  • Embodied CO2 is not widely understood but this study shows that it accounts for 28% of CO2 emissions over the first 50 years’ lifetime of a new house. Embodied CO2 is an investment in the environmental sustainability of a house. Refurbished old homes have lower embodied CO2 and therefore a distinct head start over new homes.
  • Many house builders claim that new homes are four times more efficient than older houses. This study shows that refurbished houses can be as just efficient as new homes.

    • On this side of the Atlantic the American Society of Interior Designers (ASID) Foundation and the U.S. Green Building Council (USGBC) have developed the ReGreen Program. The ReGreen Home Remodeling Guidelines compiles best practices and educational resources for sustainable residential improvement projects. Their goal is to increase understanding of sustainable renovation project practices and benefits among homeowners, residents, design professionals, product suppliers and service providers to build both demand and industry capacity.

    There is an undeniable appeal in a new, energy efficient, sustainably built home. But, I find restoring and improving an older home at least as gratifying. Taking on part or all of the home efficiency improvement projects myself only adds to the appeal. I'm excited that I can transform my humble, suburban ranch home into an model of sustainable and efficient housing. Now, that is a revolutionary idea!

    More Info:

    Guardian - Home is where the heat is: why old can be good as new

    The Empty Homes Agency - UK

    New Tricks With Old Bricks - Key Findings

    New Tricks With Old Bricks - Full Report

    ReGreen Program

    ReGreen Home Remodeling Guidelines

    Wikipedia: 1973 Oil Crisis

    Carbon Footprint

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