Oakleigh builds the whole bay in its shop: frame, panels, cornice, brackets and windows. It arrives on site as one preassembled unit, which cuts the time the facade is open.
The original bay is measured by hand on site, and every profile is copied rather than approximated, so the new bay can satisfy a landmarks commission that requires it to look identical, down to the panels under the windows and the corner posts.
On an 1844 brownstone in New York's first historic district, the old bay had little structure left. Oakleigh rebuilt it in the shop with simulated double-hung windows, and it went in within weeks, with air sealing, waterproofing and insulation it never had.