Aging Homes in the PNW: Inspecting 20–40-Year-Old Roofs, HVAC, and Electrical Systems

Across the Pacific Northwest, a lot of inventory is 20–40 years old. Those homes often have original or second-generation roofs, HVAC, and electrical systems that are near or past typical lifespans. Here’s what inspectors commonly find and how to think about repair costs and priorities.

Roofs: Asphalt shingle roofs in this age range are often in the final third of their life or already failing. We look for curling, granule loss, soft spots, and failing flashing. Expected lifespan for 3-tab is often 20–25 years; architectural shingles may go 25–30. Repair costs for a full replacement in the Seattle area often run from the mid-teens to the mid-twenties. A thorough roof inspection will note condition, approximate remaining life, and any repairs that might extend it.

HVAC: Furnaces and heat pumps in the 15–25 year range may still run but at lower efficiency and with higher failure risk. We check age, condition of the heat exchanger, airflow, and thermostat operation. Replacing an aging system can cost $5,000–$15,000 or more depending on type and size. Regular maintenance can extend life; budgeting for replacement in the next few years is prudent when the unit is old.

Electrical: Panels from the 1980s–90s may be 100-amp or less; older wiring may include aluminum branch circuits that need evaluation. We note panel type, amperage, and any safety concerns such as double-tapping or missing GFCI protection. Upgrading to 200-amp service and addressing aluminum or undersized wiring can run from a few thousand to well over $10,000. Safety items should be prioritized.

General priorities: address safety and water intrusion first (electrical hazards, active leaks, structural issues). Then plan for major system replacements based on age and condition. Maintenance—cleaning gutters, servicing HVAC, and keeping ventilation adequate—helps older homes perform better and can delay some big-ticket items. For aging homes in the PNW, a detailed inspection and a clear repair budget make it easier to buy and maintain with confidence.