Why Your Old Home is Costing You Money & Energy (And What to Do About It)

Older homes have character, history, and charm—but they’re also likely costing you much more in energy bills than necessary. In our latest GreenTech Pulse episode, we spoke with Robert Hamerly, founder and CEO of GreenSavers, who has spent the last 18 years transforming nearly 1,000 older homes annually into energy-efficient living spaces.

The Hidden Energy Drain in Your Home

If your home was built before the 1970s, there’s a good chance you’re dealing with:

• Virtually no wall insulation – Many older homes were built with empty wall cavities
• Outdated electrical systems – Including hazardous knob and tube wiring that prevents proper insulation
• Inefficient heating systems – Often using 2-3 times more energy than modern alternatives
• Air leaks and drafts – Creating temperature differences between rooms and floors
• Single-pane windows – Acting as little more than thin barriers against the elements

“When you get into a home in Oregon built before the 1970s, the chances are that the walls are not insulated,” explains Hamerly. This single factor can be responsible for massive heat loss during winter months.

The Most Impactful Upgrades for Older Homes

According to Hamerly, homeowners should focus on these key improvements for the biggest energy savings:

1. Insulate and Air Seal the Attic

The top of your home—the “lid” as Hamerly calls it—is where you’ll see the most immediate benefits from improvements. Hot air naturally rises and escapes through every small gap, creating a “stack effect” that pulls cold air in from below.

“A good attic assembly has the air sealing that is the shell to keep to reduce the airflow back and forth, and then you have the insulation which is the thermal break,” explains Hamerly. “It’s similar to wearing a puff jacket with a shell on the outside to stop the wind and rain.”

2. Insulate Uninsulated Walls

Though more labor-intensive, adding insulation to previously empty wall cavities makes a dramatic difference in both comfort and energy consumption. Modern techniques allow professionals to add insulation without permanently damaging the character of historic homes.

“We can typically remove the siding, whether it be lap siding or cedar shake, and then put it back when we’re done,” says Hamerly. “With some paint to touch up, you’ve never known that the wall now has insulation in it.”

3. Install Modern Heat Pump Systems

Once your home is properly sealed and insulated, modern heating and cooling systems can work efficiently. Today’s inverter-driven heat pumps are dramatically more effective than older models.

“Modern heat pumps can operate at full capacity down to five degrees Fahrenheit, sometimes even negative five degrees,” Hamerly notes. This is a vast improvement over older heat pumps that would start to lose efficiency around freezing temperatures.

In homes previously heated with electric resistance heaters (like wall-mounted cadet heaters or baseboards), Hamerly says they regularly see winter heating bills cut in half—from approximately $300 per month to $150 for a typical 2,000 square foot home.

The Return on Investment Question

When considering these upgrades, many homeowners naturally worry about costs. Hamerly approaches this from multiple angles:

1. Financing options: Many energy-efficient upgrades can be financed with monthly payments lower than the resulting utility savings
2. Available incentives: Look for utility company rebates, state programs, and federal tax credits
3. Improving technology: While labor costs remain steady, many green technologies are becoming more affordable over time

“If your utility bills are going to reduce by $100 and your financing bill for this work is $120, then net-net you’re only spending $20 a month,” Hamerly explains.

DIY Energy Improvements Anyone Can Make

For homeowners not ready for major renovations, Hamerly suggests these do-it-yourself improvements:

Focus on Air Sealing

“I think the air sealing one is a good one where homeowners can make an impact,” says Hamerly. Look for:

• Gaps around attic access hatches
• Penetrations around exhaust fans
• Areas where pipes or wires enter the home
• Spaces under exterior doors

Simple materials like caulk, weatherstripping, and expanding foam from hardware stores can make a significant difference.

Update Light Bulbs

Switching from incandescent bulbs to LED lighting can significantly reduce electricity usage. As one podcast listener discovered, a single 100-watt bulb can dramatically impact energy consumption in homes with limited power.

Consider a Heat Pump Water Heater

While requiring some DIY skills, installing a heat pump water heater is within reach for homeowners comfortable with basic plumbing and electrical work. “If you change the brake pads on your car, you probably could change a water heater as well,” suggests Hamerly.

Planning for Your Home’s Future

Hamerly emphasizes the importance of long-term thinking when upgrading older homes:

• Consider how long you plan to stay: This helps prioritize investments
• Plan for future needs: Electrical upgrades should account for potential EV charging, solar panels, or battery systems
• Think about aging in place: Systems requiring manual labor (like wood stoves) may become burdensome over time
• Adapt to changing climate: Areas that historically didn’t need air conditioning may now benefit from heat pumps’ cooling capabilities

“Think about how you’re using your home today and how you want to use it 20 years from now,” advises Hamerly.

The Takeaway

The conversation with Robert Hamerly highlights how proper upgrades to older homes can dramatically reduce energy consumption while increasing comfort and preparing for a more sustainable future. By focusing on the building envelope first—insulation and air sealing—then upgrading to modern heating and cooling systems, homeowners can transform century-old structures into comfortable, efficient living spaces.

To learn more about home energy efficiency or to connect with GreenSavers, visit greensavers.com.

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Listen to the full conversation with Robert Hamerly on the GreenTech Pulse podcast, available on Apple Podcasts, Spotify, or wherever you get your podcasts.