Architect Registration Examination PDD Release Date

In cold climates, the vapor drive is from the warm interior to the cold exterior during winter. The vapor retarder/barrier belongs on the warm-in-winter side of the assembly—i.e., behind the interior gypsum, before the framing/insulation—to prevent interior moisture from reaching cold layers where it could condense.

PDD references: Psychrometrics & vapor drive; vapor retarder placement (ASHRAE; IBC/IECC guidance; ARE 5.0 PDD—Thermal & Moisture Protection).

Control joints in concrete masonry walls are designed to accommodate movement caused by thermal expansion, moisture changes, and settlement.

Control joints should be placed at locations of stress concentration, such as changes in wall height, changes in wall thickness, or at large wall expanses.

They are not placed at the first course of masonry (which is typically reinforced and anchored to the foundation).

They are generally not placed at window corners or in the center of window openings but rather at planned intervals or changes in geometry.

Placing a control joint at changes in wall height allows movement without cracking.

When coordinating construction documents, heating duct clearances and tolerances in suspended ceiling plenum spaces must be verified with:

The mechanical engineer (for duct sizing and layout)

The ceiling manufacturer (to confirm the clearance requirements, installation tolerances, and compatibility with the ceiling system)

The ceiling manufacturer provides critical information on allowable spacing, panel sizes, suspension system limits, and any required clearances around ducts or pipes that run above the ceiling.

Other parties:

HVAC contractor executes installation but follows design and ceiling guidelines

Electrical contractor coordinates separate systems

Structural engineer focuses on load and framing, not ceiling duct clearance

Coordination is essential in PDD. When a clash arises, the architect must consult with the responsible consultant (plumbing engineer). This supports Objective 3.1: Coordinate consultant drawings.