The short answer
There is no single reliable lifespan for every residential window. Material, product construction, exposure, installation, maintenance, operation, water management, and available repairs differ, so condition and project goals are more useful than an unsupported age cutoff.
- Review operation, glass, frame, seals, drainage, and opening condition.
- Keep product and maintenance records when available.
- Ask what a proposed repair or replacement addresses.
Sources
Sources
- Window Types and Technologies — U.S. Department of Energy
- Window Installation — U.S. Department of Energy