With over 4000 Accor properties and a hotel typically undergoing an extensive renovation every 10-20 years, there are probably a few hundred hotels undergoing renovation at any iven time.
Anyway, here are a few additions:
Fairmont Royal York Toronto - ongoing renovation of rooms/suites started ~two years ago; currently the entire lobby and attached restaurant is closed for renovations
Fairmont Singapore - ongoing renovation of rooms/suites; some reports of Gold lounge closed this year
Fairmont Miramar Santa Monica - major re-construction, demolition of bungalows and addition of a new building announced for 2019, but not sure about status quo