Sunset Park runs uphill from the waterfront, and the grade is a working condition rather than a piece of scenery. On the numbered streets between Fourth and Seventh Avenues the pavement slopes under the stoop, so a glass lift has to be levelled and cribbed before it can pick anything up, and on the steeper blocks it often cannot stand at all — the panel goes up the stoop and in through the parlor instead. The houses themselves are mostly limestone and brick, built in long uniform runs in the first decades of the last century, and that uniformity is misleading: the openings were reglazed piecemeal over ninety years, so two houses that look identical from the kerb can take two different frame depths. We survey by house, not by block. Many of them are two- and three-family homes with the owner’s family on one floor and relatives or tenants on another, so almost every job here is done in an occupied building, in stages, with the opening closed before the crew leaves.

The commercial side of Sunset Park is unusually demanding on glass. Eighth Avenue and Fifth Avenue are two of the busiest small-frontage retail strips in Brooklyn, and the shops trade from early: produce and goods go out onto the sidewalk at dawn, awnings come down over the display glass, and deliveries run through the morning. A full display pane on either avenue is measured during trading hours and set before the street fills, which in practice means an early start rather than an evening one. Below Third Avenue, close to the harbour and under the elevated expressway, exposure is the deciding factor — salt-laden air pits untreated aluminium and attacks fixings, grime loads up fast, and hardware and finishes have to be specified for that environment rather than for a sheltered inland street. On the newer Fourth Avenue apartment buildings the work is window-wall and lobby glazing, booked through building management with freight and COIs arranged in advance.