Spring: check what winter did
Look at the roof and trim for storm damage, check fasteners and flashing, clean gutters and make sure water drains away from the building. Inspect doors and tracks and lubricate hardware.
Walk the building after a heavy rain to see where water goes.
Summer: ventilation and pests
Open vents and doors for airflow, check for wasp nests and rodent entry points, and keep vegetation trimmed back from walls. Check electrical fixtures and outlets, especially in dusty or humid areas.
Fall: prepare for the cold
Clear gutters of leaves, seal gaps around doors, check weatherstripping and make sure drains and hydrants are ready for freezing. Stack firewood and hay away from walls and keep storage dry.
Winter: watch the weather
After snow or ice, check for roof damage and clear heavy buildup from low-slope or flat sections if it is safe. Keep paths and door approaches clear, and watch for frozen pipes.
Every year
Tighten loose screws, touch up scratches in metal coatings to prevent rust, reseal wood and check posts at ground level for moisture and rot. Small repairs are cheap compared with large ones.
Walk the building twice a year with a ladder and a flashlight; small fixes now prevent big repairs later.
