Preventive maintenance, scheduled by what tends to break

Almost every emergency maintenance call traces back to something that wasn't being checked on a schedule. A water heater that floods a basement was making noise for six months. A roof leak started as a missing shingle a year before the ceiling stained. The point of preventive maintenance is not to do more work; it's to spend a smaller, predictable budget on inspection so you don't spend a larger, unpredictable one on emergencies.

Schedule by what fails, not by the season

Most preventive-maintenance calendars are organized by season ("spring inspection") because that's how the trade publications grouped them. A more useful organizing principle is what tends to fail at what age. A new building has different priorities than a fifteen-year-old building, which has different priorities than a thirty-year-old one.

Quarterly checks (every property, every age)

The minimum baseline. About thirty minutes per unit:

• HVAC filter: Replace or clean. Cheap, prevents motor strain and air quality complaints.
• Smoke and CO detectors: Test each one. Replace batteries if older than six months. Replace the unit itself if older than ten years (smoke) or seven years (CO).
• Water leaks: Walk under sinks, around toilets, water heater, and dishwasher. Look for stains, dampness, mineral residue.
• GFCI outlets: Press the test button on each. Reset if it trips. Replace if it won't.
• Exterior: Quick walk-around looking for missing siding, broken windows, gutter blockages, and signs of pest activity.

Semi-annual checks (every property)

Spring and fall, about an hour per unit:

• HVAC service: Heating in fall, cooling in spring. Have the system inspected by a tech, condenser coils cleaned, refrigerant checked.
• Gutters and downspouts: Clear, check pitch, verify discharge is moving water away from the foundation.
• Caulking: Tubs, showers, sinks, exterior windows, exterior penetrations. Re-caulk anything cracked or pulled away.
• Weather seals: Door sweeps, weather-stripping, garage door bottom seal.
• Water heater: Drain a few gallons from the bottom to flush sediment. Test the temperature/pressure relief valve.
• Trees and landscaping: Trim anything within six feet of the building. Branches against siding and roof are a major source of damage.

Annual checks (every property)

Once a year. Two to three hours per unit, plus contractor visits:

• Roof inspection: Either by you with binoculars or by a contractor. Look for missing shingles, lifted flashing around penetrations, granule loss in gutters.
• Electrical panel: Have an electrician open the panel to check for warm breakers, double-tapped breakers, signs of arcing.
• Pest: Treatment or inspection by a licensed company.
• Chimney and flue (if present): Sweep and inspect, especially with wood-burning appliances.
• Dryer vent: Clean from the dryer all the way to the exterior. The single most common cause of laundry-room fires.
• Plumbing supply lines: Inspect washer hoses (replace every five years; this is the cheapest insurance against a major flood).

Five-year property: what tends to fail

Newer construction. The major systems are still under most warranties. The failures cluster in:

• Settlement cracks in drywall and around windows. Cosmetic but worth tracking.
• Builder-grade caulk and grout failing earlier than expected.
• Garbage disposals, dishwashers, and microwaves reaching the end of their first life.
• Initial HVAC service items that the warranty company won't cover.

Fifteen-year property: what tends to fail

The middle years. Major systems are middle-aged, finishes are wearing. Plan for:

• Water heater replacement (typical life 8–12 years for tank, 15–20 for tankless).
• HVAC components: capacitors, contactors, blower motors. Whole-system replacement starts to come into view.
• Roof: depending on shingle quality, may have 5–10 years left on a 20-year roof. Get an inspection at year 15 to plan replacement.
• Window seals failing in double-pane glass.
• Carpet and flooring wear that is beyond rejuvenation.
• Fixture refresh: faucets, light fixtures, cabinet hardware. Cosmetic but materially affects rentability.

Thirty-year property: what tends to fail

Major systems are at end-of-life or beyond. The strategy shifts from preventive to planned replacement:

• Plumbing supply lines (galvanized, polybutylene, or early PEX): consider whole-house repipe planning.
• Sewer lateral: video inspection from cleanout to street. Root intrusion and bellying common.
• Electrical service: panel may need upgrade (especially Federal Pacific or Zinsco panels, which are insurance issues).
• Roof: likely on second roof; may need third.
• HVAC: definitely on second system; plan for third.
• Foundation: monitor for movement, especially in clay-soil regions.

What it costs (roughly)

Quarterly checks done by you or a handyman: $0–$300/year per unit. Semi-annual contractor visits (HVAC, gutters): $300–$700/year per unit. Annual specialist visits (roof, electrical, pest): $400–$900/year per unit. Total preventive budget: $700–$1,900/year per unit, scaling with property age.

Compare that to a single emergency: a water heater failure with floor and drywall damage is typically $4,000–$15,000. A water-line break in a wall is $5,000–$25,000. A roof leak that's been going for a year is $8,000–$40,000. The math on prevention is favorable on average and overwhelming on a portfolio.

How to actually do it

Calendar the checks. Assign each to a specific person (you, your handyman, or a contractor). Track completion in writing — even a one-line note in a spreadsheet ("HVAC filter replaced 2026-04-12, M. Khan apartment") becomes useful documentation if you ever need to defend a habitability claim or argue with an insurance carrier about a covered loss.

Most preventive maintenance is not skilled work. It's the discipline of doing it on a schedule, by someone who knows what to look for. The schedule is the product, not the labor.