A dry-hung stone facade is nothing like a standard painted exterior. The stone layer adds thickness, and it is never perfectly uniform. For the windows, that changes everything: opening dimensions, profile selection, frame depth, drainage design, weep hole placement, and the operable clearance of the sashes. Every one of these must be engineered differently from a typical facade project.
What changes when the facade is stone
Opening Measurement & Final Dimensions
Openings are measured against the finished stone surface, not the paper drawing.
Profile & Frame Depth
Profiles are selected to absorb stone thickness variance and keep the reveals clean.
Finished Window Appearance
The complete unit must sit flush and true against an uneven stone plane.
Drainage & Weep Holes
Drainage paths and weep positions are recalculated so water exits in front of the stone, never behind it.
Sash Operation & Clearance
Operable sashes are verified for full travel and closing clearance against the real finished face.
Ideal sequence vs. real-world sequence
Ideal Sequence (Textbook)
The stone facade is completed first. Then the openings are measured on site, window dimensions are optimized against the real stone surface, and profiles and glass are selected or adjusted to match.
Real-World Sequence
Once the architectural drawings are approved, the developer expects all trades to move simultaneously — structure, facade, windows, interior fit-out — and material procurement starts immediately. Nobody can wait for someone else to finish first.
One Tolerance Chain. Four Trades.
Every party — the structural contractor, the facade contractor, the window supplier, and the interior fit-out team (especially window sill and casing design) — must lock in their dimensions before ordering materials. A single tolerance chain runs through all of them. If any party sets their numbers in isolation, the stack-up fails somewhere downstream. The result is not just cosmetic: lost materials, rework costs, blown schedules — and in the worst case, windows that cannot drain, cannot close, or cannot be installed at all.
Structure — base dimensions · Facade — finished face position · Windows — unit + drainage geometry · Interior Fit-out — sill & casing interface
"Our job is to make sure that conversation happens before money is spent."
This note comes from a villa project where the facade was dry-hung stone — you can see the drawings and the delivered result in the neoclassical villa case study.