Most San Francisco apartment buildings were built before 1979, which means most of them have already replaced their major systems once — or are overdue. Knowing which is which is the difference between a budgeted expense and an emergency.
The failure order
In our experience with pre-war and mid-century buildings in the city, systems tend to demand attention in a fairly consistent order.
Drainage and waste lines first. Cast iron waste piping has a finite life, and in buildings of this vintage a great deal of it is at or past it. Failures start as slow drains and recurring backups and end as a pipe failure inside a wall. Camera inspection of main lines is cheap relative to what it prevents.
Then supply plumbing. Galvanized supply lines corrode from the inside, which is why they fail without warning after decades of looking fine. Reduced pressure and rusty water at first draw are the tells.
Then the roof. Flat and low-slope roofs common on San Francisco apartment buildings have shorter service lives than pitched roofs and are less forgiving of deferred attention. Ponding and failed flashing at parapets do most of the damage.
Then electrical. Original service capacity in older buildings was sized for a very different set of appliances. Knob-and-tube remnants persist in some buildings and are an insurance and safety issue as much as a capacity one.
Windows and envelope throughout. Not usually urgent, frequently the largest single line item, and the one most tied to resident comfort and complaint volume.
The seasonal work that prevents most claims
San Francisco’s rain arrives concentrated, and the buildings that come through winter without a claim are the ones where three things happened in autumn.
Gutters and downspouts cleared. Blocked drainage is the origin of a startling share of water intrusion. It is also the cheapest thing on this list.
Roof and flashing inspected. Before the rain, not during it. Parapet flashing, penetrations and any ponding areas.
Site drainage checked. Where water goes when it leaves the roof matters as much as the roof. Grade, area drains and any below-grade spaces.
Soft-story retrofit
San Francisco has required seismic retrofit of qualifying wood-frame multi-unit buildings — typically those with weak ground floors, often open garage or retail space beneath living units — under a mandatory program with compliance deadlines. Whether a building is on the list is public record. Owners acquiring a building should confirm status as part of diligence rather than discovering it later.
The economics of deferral
Deferred maintenance is not saving. It is borrowing at an unfavorable rate.
A failing valve replaced on schedule is a small planned expense. The same valve after failure is emergency labor, water damage remediation, possible resident displacement, a habitability exposure and an insurance claim that affects future premiums. The multiple is routinely ten to fifty times.
The second cost is less visible: buildings with visible deferred maintenance attract residents who expect less and tolerate more, and lose the residents who would have stayed longest.
Building a plan that works
The useful version of preventive maintenance is boring and specific.
Inventory the major systems and record their age and condition. Where the age is unknown, that itself is information — assume the worse case until it is inspected. From that inventory, produce a rough replacement sequence with approximate timing, and revisit it annually.
Then put the seasonal items on a calendar and let them happen without a decision each time. Gutters in October is not a judgment call.
For most buildings this produces a capital plan that is legible enough to budget against and rough enough to be worth actually maintaining. That is the goal — not precision, but enough foresight that nothing major arrives as a surprise.
If you own a pre-1979 San Francisco building and do not currently have a system inventory, that is the single most useful thing to build this year, whoever manages the property.