Buy the door from the shop that will measure it. For Upper Saddle River, that is Accurate Glass & Mirror, about 14 minutes from its Midland Park showroom on Greenwood Avenue and reachable at (201) 507-5918. Timing matters as much as address: the glass is cut to finished tile, so the measure comes after the tile does.
The order of operations here is not flexible. Tile, curb and pan have to be finished and set before a measure, because the panels are cut to those exact surfaces. Measuring against bare studs or a mortar bed produces numbers that stop being true the moment tile adds its thickness. Waterproofing, tile, grout, measure, fabrication, installation: that sequence is what keeps a frameless enclosure from arriving in the wrong size.
The practical move is to book early and measure late. A phone call while tile is still going up puts the project on the calendar; the visit itself waits until the walls are done. Fabrication follows the approved quote, and an installation date is set once panels are cut and edged, which is why glass is usually the last trade to touch the bathroom. Booking the call early costs nothing and keeps the enclosure from becoming the reason a finished room sits unused. Tile crews rarely finish on the day they predicted, and a booked slot absorbs that better than a cold call does.
Before the tile, not after. A contractor can place solid blocking behind the wall where hinges and clamps will anchor, keep the curb level and correctly pitched, and avoid running a niche or a bench through the line the glass wants to follow. Those decisions cost nothing while the wall is still open and cost a great deal once it has been tiled and grouted. A shower head aimed straight at the door seam is another detail worth raising while plumbing is still rough, since the glass can only manage water the layout sends at it.
It is also worth agreeing on who is responsible for the glass. When the enclosure is bought directly from a glass shop, the measure, the fabrication and the installation stay under one roof, and the crew answering for the fit is the same crew that took the dimensions. An Upper Saddle River project handled that way has one fewer handoff available to go wrong.
A preliminary visit can confirm layout and rough dimensions, which helps a contractor plan blocking and curb height. The fabrication measure still has to wait for finished tile, since a quarter inch of tile and thinset changes every panel. Treating those as two separate visits keeps a project moving without risking a wrong cut.
Whoever makes the decisions about layout and finish. The visit settles door swing, panel arrangement, glass thickness and hardware, and those answers go straight onto the cut list. If a contractor is running the bathroom, having both people present is ideal, because questions about blocking and pitch get answered on the spot instead of by voicemail.
Call (201) 507-5918 while the bathroom is still in progress, and the visit can be timed to the week the tile is finished. Midland Park sits about 14 minutes away by appointment, and the residential measure is free.