Measuring Windows for Custom Drapery
Why every dimension is measured to the sixteenth, by the installer, on site — and the seven measurements that have to be on the spec before fabric is cut.
The studio does not fabricate from client-supplied measurements. We do not fabricate from measurements emailed by a builder. We do not fabricate from architectural drawings. Every project the studio accepts is measured on site, in person, by the installer who will be hanging the work, to the sixteenth of an inch, and recorded against a written measurement sheet that is signed before fabrication begins.
This is the single most over-looked discipline in residential drapery work, and the single most consequential. A panel cut to a wrong dimension cannot be fixed at install — it can only be re-fabricated, at the studio's cost, with weeks of delay. Measurement is where projects succeed or fail.
Why client-supplied measurements are not accepted
Homeowner-supplied measurements are accurate roughly half the time. Builder-supplied measurements are accurate roughly seventy percent of the time. The errors that defeat the other half are not in the obvious dimensions — they are in return depth, plumb out-of-wall, floor levelness, and sill projection. These are dimensions a homeowner does not know to measure and a builder does not measure to drapery tolerance.
The studio's installer measures every opening as if the panel will be cut to that measurement and never re-cut. Because it will be.
The seven measurements on every spec
Finished length: from the planned mounting height down to the finished floor (for floor-length panels), to the sill (for sill-length), or to one inch above the sill (for above-sill applications). Measured at three points across the opening to confirm floor level.
Mounting width: outside-to-outside of the planned hardware or track, including hardware projection on both sides. This is the dimension that determines the rod or track cut length, not the window width itself.
Return depth: from the wall plane out to the front face of the hardware. Determines the wrap-around panel width and the visual relationship between the hardware and the architecture.
Stack-back clearance: the horizontal space available on each side of the opening for the panel to stack when fully open. Determines whether the panel can clear the glass when retracted.
Mounting surface: drywall, plaster, wood blocking, ceiling, beam, or millwork. Determines the hardware specification and the fastener type.
Plumb and level: deviation of the wall from plumb and of the floor from level across the opening. Recorded so the workroom can compensate at fabrication for openings that are out of square (most of them are).
Obstruction map: HVAC registers, baseboard heaters, electrical outlets, switches, sconces, security sensors, alarm panels, and any architectural element within the panel's swing or stack zone. Recorded photographically with dimensions.
When measurement happens in the project timeline
Measurement is a separate appointment from consultation. The consultation establishes the design specification — pleat, fullness, mounting, hardware — and confirms the rooms. Measurement happens after the specification is signed and after any architectural work that affects the openings (drywall, painting, millwork, baseboard, flooring) is complete.
On new construction, the studio is on site at framing for rough-in coordination, at drywall for pocket and blocking confirmation, and again for finish measurement immediately before fabrication. Three site visits across a project is the studio standard for new construction; one is the standard for finished residences.
Tolerances and what they mean for the homeowner
Finished length tolerance: ±1/8 inch from spec. A floor-length panel that is half an inch short reads as visibly short across the room.
Mounting width tolerance: ±1/4 inch from spec. Hardware cut wide of spec stops short of the planned return; cut narrow of spec extends past the planned return.
Return depth tolerance: ±1/8 inch. The visual relationship between the hardware and the wall plane is precise enough that an eighth of an inch reads in finished work.
Floor-out-of-level tolerance: zero. The panel is fabricated to match the floor across the opening, not to a single dimension. A floor that drops half an inch across a twelve-foot window has a panel hem that drops half an inch with it.
Questions homeowners ask us
- Can I take my own measurements to get a faster quote?
- For a budget estimate, yes — the studio can quote against rough dimensions to give a homeowner a project order of magnitude. For fabrication, no. Every project the studio fabricates is measured by the installer regardless of any earlier dimensions the homeowner supplied.
- How long does on-site measurement take?
- Roughly fifteen to twenty minutes per opening for a finished residence, including photography and obstruction mapping. A full primary-suite or great-room project measures in two to three hours. New construction measurement, including rough-in coordination, is a half-day on site.
- What happens if the homeowner makes architectural changes after measurement?
- The opening is re-measured. Any architectural change after measurement (baseboard added, ceiling finished, paint redone, floor changed) invalidates the original measurement and requires a return visit before fabrication. Re-measure visits are included in the studio's fabrication standard at no additional cost when scheduled inside the project timeline.
- Is laser measurement used?
- Yes, in combination with steel tape. Laser is used for ceiling heights, large openings, and any dimension where the distance exceeds reliable tape work. Steel tape is the studio default for finished dimensions because a tape against finished material is the most accurate available measurement at drapery tolerance.