When a Field Dimension Has Not Been Verified
Unverified field dimensions introduce latent structural risk into architectural records. This standard defines systematic notation, tolerance thresholds, and operational escalation procedures for structural components that remain obscured, inaccessible, or unmeasured during on-site documentation.
Mandatory Notation & Assumption Disclaimers
Whenever demolition has not exposed structural framing, or physical barriers prevent direct laser calibration, drawings must never present extrapolated values as absolute. Dimensional values must carry standardized prefixes and explicit coordinate callouts.
Zero-Presumption Policy
Nominal partition thicknesses, interstitial plenum heights, and concealed bearing conditions remain cataloged under provisional status until intrusive physical verification is formally scheduled and logged.
Verification Protocol Selector
Select a dimensional classification status to review drafting notations, permissible assumptions, and site actions.
Verify in Field Marker
Applied when existing finishes or obstructions prohibit physical measurement. The numerical dimension is enclosed in brackets with a bold [VIF] note directing the contractor to confirm exact clearance prior to millwork fabrication.
Nominal Assembly Offset
Utilized when historic plan sets indicate structural grid spacing but interior wall build-ups remain closed. Values rely on documented era averages with explicit upper and lower tolerance envelopes (+/- 1.25 inches).
Critical Structural Hold
Placed on critical load-bearing column nodes or elevator shaft plumb lines where discrepancies exceed acceptable limits. Disallows any downstream detailing until physical bores or selective demo are performed.
Rough Opening Estimate
Identifies window and door masonry reveals where trim casing obscures king stud or header positioning. Ensures fenestration schedules remain tentative until casings are dismantled during preliminary site prep.
Plenum & Joist Depth Modeling
Applied to ceiling cavity spaces where mechanical ductwork or dropped acoustic tile ceilings impede laser scanning of the joist underside. Preserves mechanical clearance allowances without claiming true structural datum.
Utility Penetration Containment
Assigned to core drilled sleeves and subterranean foundation conduit routes where as-built utilities conflict with modern structural shear walls. Suspends core drilling until electromagnetic tracing completes.