San Francisco’s older homes- with their charm, character, and classic architecture- are part of what makes the city so special. But if you live in one, you’ve probably noticed something else that comes with all that history- it’s more challenging to keep them warm.
From chilly mornings to drafty nights, older homes in the Bay Area tend to lose heat faster than modern ones. Let’s explore why that happens and what you can do to stay comfortable (and save on your energy bills).
1. Poor Insulation- or None at All
Many of San Francisco’s historic homes were built before insulation was standard practice. Walls, floors, and attics may have little to no insulation, which means warm air escapes just as fast as your furnace produces it.
What to do:
- Have an HVAC technician or insulation professional assess your home’s thermal performance.
- Consider attic or wall insulation upgrades, which can significantly reduce heat loss.
- Seal small cracks or gaps in your baseboards, windows, and floors- especially in Victorian or Edwardian homes where materials expand and contract over time.
2. Drafty Windows and Doors
Single-pane windows are one of the biggest culprits of heat loss in older homes. Wood frames may warp or crack with age, and old seals let cold air seep in. Even beautifully preserved original windows can be a source of drafts.
What to do:
- Install weatherstripping or caulking around windows and doors.
- Use thermal curtains during the colder months.
- If possible, upgrade to double-pane windows or add storm windows that preserve your home’s character while improving efficiency.
3. Leaky Ductwork
Over time, ducts in older homes can develop small leaks or separations, especially if they’ve been patched or added onto over decades. When ducts leak, warm air escapes into attics, basements, or crawl spaces instead of your living areas- meaning your furnace works harder for less comfort.
What to do:
- Schedule a duct inspection and sealing service.
- Replace old or damaged ductwork to restore full heating efficiency.
- If your home doesn’t have a modern duct system, consider ductless mini-splits- a great option for older San Francisco homes where installing new ducts isn’t practical.
4. Aging Heating Systems
Older furnaces, especially those over 15–20 years old, lose efficiency over time. They may cycle more often, produce uneven heat, or struggle to maintain consistent temperatures in drafty homes.
What to do:
- Schedule a furnace inspection and tune-up before winter.
- Ask about high-efficiency heating options that can adapt to your home’s needs- like variable-speed furnaces or hybrid systems.
- Replacing an outdated unit can reduce energy waste and improve comfort, often paying for itself in lower utility bills.
5. Poor Ventilation and Airflow
Many older homes weren’t designed with modern airflow in mind. Blocked vents, outdated duct design, and closed-off spaces make it harder for heat to circulate evenly. You might notice certain rooms that stay cold no matter how high you turn up the thermostat.
What to do:
- Make sure all vents are open and unobstructed.
- Have your HVAC technician balance the airflow and test for temperature differences.
- In some homes, zoned heating or a ductless system can provide a more efficient solution.
How Bay Air Heating & Cooling Can Help
At Bay Air Heating & Cooling, we specialize in optimizing comfort for San Francisco’s unique and historic homes. Our team can evaluate why your home is losing heat and recommend cost-effective, lasting solutions- from duct repair and sealing to energy-efficient furnace installation or smart thermostats that learn your heating patterns.
We take a holistic approach- improving comfort, energy efficiency, and safety- while respecting the character and architecture that make your home special.
Older San Francisco homes were built to last- but not necessarily to retain heat efficiently. The good news is that with the right combination of insulation, airflow improvements, and heating system upgrades, you can stay warm without losing your home’s historic qualities.
Ready to Stop Losing Heat This Winter? Contact Bay Air Heating & Cooling today for an inspection or consultation. We’ll help you identify the root causes of heat loss and create a solution that fits your home and budget.