The question owners ask after "what will it do for the grade" is "what will it do to my tenants". Here is how we sequence a glazing upgrade in a building that stays open: one opening per visit, worst elevation first, storefronts around trading hours, and the access plan that drives the whole schedule.
In short: An energy upgrade to the windows and storefront of an occupied commercial or mixed-use building is planned around the people in it. We sequence the work by elevation and by stack, replace each opening in a single visit so no unit is left open overnight, protect the interior, and schedule storefronts and entrances around the tenant's trading hours. The survey tells us the types and counts; the phasing plan tells the owner which floors are affected on which days and what the tenants need to do, which is usually nothing more than clearing a window sill.
Every window or storefront bay is removed, installed, sealed and cleaned in the same visit. The old unit comes out in the morning and the new one is in and weather-tight before the crew leaves. Nothing is left open, boarded or tarped overnight in an occupied building. This fixes the crew size and the daily count: a two-person crew replaces three to six residential-size windows a day depending on floor and access; a storefront bay is a day or two for a larger crew.
The exception is glass-only replacement, where the frame stays and each unit is a matter of minutes: a crew can move through a whole elevation in a day or two with the tenants barely aware of it. That is one of the reasons we check whether the frames can take new glass first; see glass-only vs full replacement.
How we reach each opening decides the schedule and a large part of the cost. From the inside, through the opening itself, is the fastest and cheapest for residential-size windows and is how most occupied buildings are done. Fixed glass too large to pass through the opening, storefronts and curtain wall need exterior access: a lift on the sidewalk (with a DOT permit), a swing stage, a mast climber or scaffold. Those are usually provided by others and listed as excluded on our estimate, and they have to be booked around the sidewalk shed, the tenant's deliveries and the neighbors.
The survey records the access per type for exactly this reason. A building where every unit can be done from inside is a different job from one where the ground floor needs a lift on a busy avenue for a week.
For what the work does for the building's numbers and obligations, start at the property energy performance page and the Local Law 97 calculator.
Minutes. Each opening is removed, installed and sealed in the same visit; nothing is left open or boarded overnight in an occupied building.
A two-person crew replaces three to six residential-size windows a day depending on floor and access; glass-only replacement is much faster. A storefront bay is a day or two for a larger crew.
No. They clear the sill and about four feet in front of the window; we protect the floor and furniture and clean up before leaving.
No. Storefront work is scheduled around trading hours and an entrance is replaced with a temporary door in place.
Yes for interior-accessible work; exterior sealing needs temperatures within the sealant's range, so exterior-heavy phases are planned for the warmer months.
Exterior access equipment is normally provided by the owner or general contractor and listed as excluded on our estimate; we specify what is needed per elevation.
Two weeks ahead, with a reminder two days before, floor by floor.
Property energy performance How we survey a building envelope Glass-only vs full replacement Installation services Commercial property services
About this page. Written by Alex GC Inc. d/b/a Alex Glass Construction and reviewed before publication by Aleksandr Chernovolenko, Managing Partner, with our design and estimating lead and a field foreman. Our foremen hold the NYC DOB Site Safety Training supervisor card and our crews the 40-hour worker card; we are certified to fabricate, install and service Alutech and Everest aluminum systems. Facts are drawn from our own projects, manufacturer test data and the applicable codes; where we are giving an opinion, we say so. Last reviewed November 2026. Credentials
Send the address and the survey or window count. We will propose the phasing by elevation and the access per type, so you can tell tenants what to expect before the work is priced.
