Energy Conservation in Older Homes

Often, when you read about energy-efficient homes, the focus is on design of new structures. I always think: “That’s great to put up solar panels, and design your house facing south, but what about the rest of us?” For homeowners in older homes without the resources to build a brand-new house, what can we do to increase the energy efficiency of our homes and save money on our power bills?

Weatherization and energy-efficient upgrades are the answer. Economically they pay for themselves after several years of use and take advantage of the existing structure of your home without the need for costly additions or major renovations.

Betsy Petttit, the author of the article “Can a Vintage Home Be Energy Efficient?” offers several suggestions for improving your home energy use without losing the charm of an older home. Pettit states that there are 58 million houses in America that were built before the 1970s. These homes remain in the market because people like the traditional floor plans, details, and historical significance. I know in Johnson City many old homes have hardwood floors and wood trim that are no longer available. An older home is a legacy that ties the owners to a continuity of a community that isn’t always available with new developments.

Luckily, old houses can be made much more energy efficient without losing any of the charm. In fact, energy conservation alone can lower your home energy use without the addition of new technologies like solar panels or passive cooling. In fact, air leaks can account for 30% of a home’s energy loss. Insulating your home is by far the easiest and most cost effective way to reduce your home energy consumption.

Pettit, herself an architect and owner of a renovation company, notes that infrastructure is the first area to examine with older homes. Water lines, wiring, plumbing, and mechanical systems are nearing the end of their useful lives after 100 years on the job. Windows are also a source of energy loss as they may have layers of paint or swollen wood that can hinder their ventilation ability.

If a homeowner is considering an addition, an alternative could be to take advantage of unused space in the basement or attic and include energy upgrades in the process. Pettit notes that this method doesn’t cost that much more because energy upgrades come up as decisions and choices are made about the project. She cites an example of replacing a heating or cooling system for $10,000, which results in $1000 a year of energy savings.

Of course, a qualified Green Building Contractor can help you make decisions about how to get the most for your money, but Pettit offers these Seven Steps to net-zero energy use:

• Upgrade the mechanical systems. This includes furnaces, boilers, window air conditioners, and
water heaters.

• Bring the basement and crawlspace inside the house. Warm, dry spaces increase the available
living and storage space. Spray foam can be used to rid wet basements of moisture that causes
high humidity levels and sources for mold growth.

• Superinsulate and air-seal the roof. Air-sealing and good insulating occur at the same time
allowing for a one-step process.

• Replace the windows. Pettit recommends Energy Star windows to keep out water and weather
extremes.

• Insulate the walls. Using cellulose in wall cavities is a cheap, easy, and effective way to
increase the warmth of your house.

• Buy Energy Star fixtures, appliances, and lighting. After structural and mechanical upgrades,
appliance energy loads are the next big source of energy loss in a home.

• Add a renewable-energy source. Pettit lists this strategy last because energy conservation
and reduction is necessary before such systems as photovoltaics or wind power are worth the
investment.

The idea of weatherization of existing homes is gaining popularity as an effective way to save money on energy costs without building a new home.

The U.S. Department of Energy, in its article “Single-Family Residential Building Weatherization” explains in detail the process of weathering your home. An interesting statistic cited in the article is that weatherization successfully reduces the average overall energy consumption of existing single-family residential dwellings by 12-23% or more.

The DOE recommends a comprehensive weatherization program that incorporates a whole-house approach. This approach examines all the systems of a house and improves them simultaneously to ensure that no energy-saving measure is lost and so that all the systems work together in the most effective way to reduce energy use. An added side benefit of this approach is a more healthy indoor environment as a comprehensive approach also examines areas where health-related problems could occur (such as carbon monoxide production, mold, radon, and contaminants). The systems examined under the whole-house approach include:

• Building shell (ceilings, walls, floors, windows, and doors)
• Heating and cooling equipment (including the control system and energy distribution system)
• Ventilation systems
• Domestic hot water system
• Lighting

The DOE states weatherization is needed for single-family homes not slated for major revitalization or renovation because “existing housing will likely represent the largest portion of the housing stock for many years to come.”

Five Steps to a Comprehensive Weatherization Program

1. A thorough home energy assessment is performed to identify house specific
deficiencies and opportunities. This assessment takes 2-4 hours.

Visual Inspection
A thorough visual inspection is performed to document current efficiency levels of the building shell, installed equipment, and lighting.

Diagnostic Testing
Diagnostic testing on the building and air distribution system is performed to determine current leakage rates and sources of leakage.

Current Operating Efficiencies
Heating and cooling equipment are gauged and potential health related problems are examined.

2. After the assessment, the costs and energy savings for each possible energy
conservation opportunity is identified and selected. Some repairs necessary for the proper performance of the selected measures may also be identified. By considering all of the opportunities at the same time, the measures selected will work together to reduce energy use most effectively.

3. Experienced installers implement the improvements. Choosing the right contractor is
essential if you want to gain the most advantage from your improvements.

4. Verification of the performance of the improvements is a crucial final step to ensure
that new systems are operating optimally and as intended.

5. Occupant education on the new systems aids in system optimization as they are
ultimately responsible for operating the systems. Topics frequently covered include:
filter changing, thermostat operation, strategies to reduce cooling load, and use of
whole house fans and ventilation systems.

Energy conservation is an often overlooked source of energy savings for older homes. Simple, cost effective renovations and remodels can improve the appearance of your home and save you money in energy costs. This post just touches the surface of weatherization, a process that can involve multiple strategies and complex decision-making. Having a knowledgeable contractor helping you through the process can result in a successful upgrade to your older home.

Resources:
Federal Energy Management Program: www.eren.doe.gov/femp/

National Energy Audit (NEAT) and Retrofit Guide available at the Oak Ridge National Laboratory website: www.eber.ed.ornl.gov

Sources:
Pettit, Betsy. Winter 2010. Can a Vintage Home Be Energy Efficient? Energy-Smart Homes.

U.S. Department of Energy. Sept. 1998. Single-Family Residential Building Weatherization.