There is construction all over San Francisco!
Here are some places you will see construction:
- Mission Bay
- the Financial District
- SOMA - especially pretty close to Embarcadero where they're building the new Transbay Terminal.
- Central Subway - the new MUNI tunnel in Chinatown
- pretty much everywhere
Here is a map from May 16, 2014 that shows lots of buildings under construction.
Features of construction:
- cranes - a beautiful new (permanent?) feature of the San Francisco skyline.
- occasional fires
Why is there so much construction?
Primarily because San Francisco is in a boom fueled by investment in technology companies. This is part of large changes happening across the Bay Area.