That strikes me as a mothballed site.
I think many of the potential answers lie in the excellent July 30, 2024 article link from Smuttynose in Post #90
Dust clouded the air just north of Coolidge Corner in recent weeks, as demolition began on the site of two historic garages which will now become the center of a major new development. The Waldo-Durgin project, decades in the making, is moving forward, although it will likely be years before a...
brookline.news
(Perhaps the ground soil needs treatment? I'm no expert in this, but that might be an explanation?)
".....Andy Martineau, development project manager at Chestnut Hill Realty, said that asbestos in the building’s interior has been abated, and that asbestos in its roof will be “abated during demolition following a work plan approved by MassDEP and the Brookline Department of Public Health.”
The company says it is using fire hoses and water cannons to wet down the buildings as they are being demolished, and will have a licensed hygienist on site full-time to monitor the air quality for asbestos during the demolition.
Also
".......Zuker says the company’s goal is to start construction in the next 18 months
(~January 2026), and he’s hoping that interest rates will come down during that time. (Soaring construction costs and inflation have stalled construction projects around
the Boston area and the country.)........"
".......In the meantime, the town and developer are in talks about whether there might be any mutually beneficial interim uses of the site. In other towns, such interim uses have included things like pop-up event spaces or outdoor movie nights......."
I'm not overly worried about the intentions of the developer at this time (subject to change, of course, but, given the above this all seems pretty much right on schedule)
".......Ed Zuker, a prominent local developer and the founder of Chestnut Hill Realty, has been eyeing the property, and buying pieces of it, for 50 years.
“To me, Waldo is a crown in my career,” said Zuker, 76, who grew up in Brookline. “I want to do something that’s really great for the town.”