Starting Point for Dimension Strings — Exterior Walls Do drafters usually begin a primary set of exterior dimensions from the inside edge of an exterior wall, or is it more common to start from a consistent exterior face or grid datum so that control is stable across trades?

Introduction / Context:
Dimension strings need a reliable baseline. Using the inside edge of an exterior wall as the primary start point is fragile because interior finishes and furring can vary by room and change after design development. Most practices instead choose an exterior face datum or a structural grid so that field layout is straightforward and changes to interior finishes do not ripple across exterior control dimensions.

Given Data / Assumptions:

• Exterior face of structure or grid lines are stable references during construction.
• Interior finish thickness may change with product selection.
• Coordination among structure, envelope, and site benefits from exterior control.

Concept / Approach:
By starting from an exterior face or a grid, the plan maintains consistent overall dimensions and aligns with site and facade control. Interior partitions can then be dimensioned from interior datums as a separate string. This layered approach prevents accumulation of finish tolerances into exterior control dimensions.

Step-by-Step Solution:
1) Select grid or exterior face as the baseline.2) Place exterior dimension strings from that baseline to key elements.3) Dimension interior partitions separately from a consistent interior datum.4) Cross check closure so totals match overall building size.

Verification / Alternative check:
Construction layout crews prefer exterior datums because they tie into site control and facade modules. Fewer change driven adjustments are needed when interior finishes move.

Why Other Options Are Wrong:
Correct would endorse a fragile inside edge baseline. Material specific limits such as Only for masonry or Only for wood framing are inaccurate. Partially correct suggests no clear best practice where one commonly exists.

Common Pitfalls:
Mixing baselines within the same string; failing to document the chosen datum in the general notes and dimensioning legend.

Final Answer:
Incorrect