Are new buildings exempted from rent control permanently, or just for a limited time?
The latter seems like it would be a workable system: incentivize new buildings by allowing the owners to charge whatever rents the market will bear for the first 10 or 20 years or so, then eventually they revert to rent control (presumably after the original construction costs have been repaid and then some).
Permanently. There was a 2020 ballot measure that aimed to change that so buildings could become subject to rent control on a rolling basis after they'd been around for 15 years or more, but it did not pass.
The latter seems like it would be a workable system: incentivize new buildings by allowing the owners to charge whatever rents the market will bear for the first 10 or 20 years or so, then eventually they revert to rent control (presumably after the original construction costs have been repaid and then some).