San Francisco is fog, wind, and houses packed close on hills. Summers stay cool and damp while much of the state is baking, and a bright afternoon is the exception, not the plan. Victorians, Edwardians, and flats share walls, bay windows, and stairs. Many of them were built to heat with radiators, steam, a wall furnace, or a floor furnace, and they still have no central air. The climate and the buildings belong together. A cooling-first plan from a hot valley does not describe a fog-belt flat.
Roofs are often flat or nearly flat, with parapets, scuppers, and sometimes a deck on top of the rooms you live in. Wood windows swell, draft, and shed glaze. Moisture lingers in baths, at sills, and under roofing that never really bakes dry. Plumbing is old, pressure is often modest, and a sewer lateral on a hill can fail in the yard long before a faucet looks wrong. Yards, when they exist, are small, shady, and windy. Pests use the shared walls and the damp.
The housing is dense and old in a way that changes every trade. You cannot assume a ducted attic, a slab, or a wide side yard. Plaster, tight closets, and painted wood siding are the normal materials. Fog drips for days. A leak may be a slow intrusion at a parapet rather than a dramatic storm. Heat is the comfort problem for most of the year. The rare warm spell only proves how few of these houses can cool themselves.
Pick the work that matches this fabric. A tired flat roof, a sash that will not close, a bath that never dries, a radiator that knocks, rodents in a shared wall, or a policy question after water stained a bay window are separate calls. Describe the building as a foggy, older, tightly built house. Do not describe it as a ranch with central air and hope the advice still fits.
Pick the trade and call.