I’d say that the Prospect Tower viewing platform is just about level with the 8th level (currently the top) floor plate of the lab bldg.
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There is actually still a core it's just made out of steel if you look closely at the cross bracing running in the middle. Some go this route for various reasons - the hub on causeway office tower did it because it's much lighter than concrete and was going on top of the existing podium that was already built independently of the potential tower@Bruins11363 @dhawkins @DwnTwnr: You folks seem to have knowledge of elevator cores. What’s with the lack of one in this lab building going up in Union Sq?? (See attachment above) I don’t recall ever seeing steel going up before/without a core.
There is actually still a core it's just made out of steel if you look closely at the cross bracing running in the middle. Some go this route for various reasons - the hub on causeway office tower did it because it's much lighter than concrete and was going on top of the existing podium that was already built independently of the potential tower