How San Francisco Was Built and Evolved Over Time

San Francisco was built fast, cheaply and in wood, then rebuilt fast after it burned.

The grid over the hills

The street plan was surveyed in the 1840s and 50s on a strict grid with no regard for topography, because straight lines sold lots more easily than contours. The consequence is streets climbing gradients that would be closed elsewhere, the cable car system invented in 1873 specifically because horses could not manage them, and a set of accidental viewpoints where a flat street suddenly gives onto the bay.

Painted Ladies

The city’s Victorian and Edwardian houses — Italianate, Stick and Queen Anne — were built in timber, often from pattern books, with bay windows to catch light on narrow lots and elaborate milled ornament that was cheap because it was machine-made. Around 48,000 were built before 1915; roughly half survive, concentrated in the western neighbourhoods that the 1906 fire did not reach.

Rebuilding after 1906

The city went back up in about three years, mostly on the old lot lines, in a Beaux-Arts idiom downtown and timber again in the districts. The Civic Center was the one grand planned gesture.

Earthquake engineering

Soft-storey buildings with garages beneath flats were the main failure mode in 1989, and a mandatory retrofit programme has since strengthened thousands of them.

Height and fog

Downtown towers cluster east; the residential city stays low, which is why the hills still read as hills.

Building on fill

The Financial District, the Marina and much of the eastern waterfront stand on made ground — rubble, dune sand and, downtown, gold-rush ships abandoned in the harbour and built over. Saturated fill liquefies when shaken, which is why the Marina burned in 1989 while neighbourhoods on bedrock a short distance away were essentially unharmed, and why the seismic map of the city tracks the old shoreline so closely.