645 Madison Avenue

New York, NY
50,000 SF

This project encompassed four projects in one in an existing 22-story mixed-use, office building, including a new lobby relocation, five stories of retail space renovation, a new glass façade and storefront and Metropolitan Transportation Authority (MTA) approvals.  Spanning over 50,000 square feet, these first five floor were completely transformed with two new additional elevators shafts and pits coupled with a new intercommunicating stair.

Located directly adjacent to an MTA subway tunnel, Bala spearheaded MTA coordination and approval efforts ultimately receiving a “Letter
of No Impact” for the new elevator pits.  This was due to our unique subgrade approach, introducing a subgrade steel frame to allow for a new load path, resulting in minimal lateral loads to be imposed onto the tunnel walls.

During excavation of the two new elevator pits, it was discovered that at that specific location there were twenty-five, subgrade ConEdison conduits serving the building with power.  Bala provided a unique approach to overcome this challenge by raising the elevator pits to an above cellar slab location, coupled with raised floor slabs and
ramps, to help mitigate a seven-figure change order to the Client.

For the relocation of the new main lobby, the existing mechanical mezzanine floor encompassing over 3,000 SF of area was required to be removed to allow for the desired high lobby ceiling heights. Altering the column’s unbraced lengths at the bottom of an existing 22 story building resulted in the need to reinforce the columns flanges with welded steel plates.