15.4 Case Study Strategy: Synthesizing Drawings, Code Sheets & Schedules

Case Studies Apply the Same Design Knowledge

PPD case studies test applying project information to design decisions, not a separate body of technical rules. Current NCARB guidance allows up to nine case studies and up to twenty case-study items in the division. Following the April 27, 2026 change, each case has one or two resources. Do not prepare around an assumed pair of large, fixed-tab cases or a mandatory 30–60-page exhibit package. The official practice exam is the best way to learn the current interface.

A resource might supply a site plan, program, drawing, schedule or technical information. Read the scenario and question for the actual facts. The task may ask for the best configuration, a feasible system, a code-related result, a cost comparison or the consequence of changing an assumption. Multiple options can be broadly plausible while only one satisfies all stated requirements.

Retrieve Evidence Efficiently

Briefly orient yourself to the scenario and available resources, then identify what the item asks you to decide. Note qualifiers such as minimum, maximum, net, gross, at least, select all, or within the budget. Identify the relevant exhibit and read its legend, units, dates and notes. A dimension without a unit or a code value without its condition can produce a convincing but wrong calculation.

Use search when supported to find a distinctive term, but inspect the surrounding material. Searching for “area” may retrieve several unrelated values. A room-area schedule is different from zoning lot area or allowable building area. Return to the question after locating evidence and verify that the selected value answers that particular task.

Record short intermediate results on the digital whiteboard if useful. Physical scratch paper is not generally allowed except as authorized through an accommodation. NCARB's break rules lock previously viewed items after a break; complete any needed review of those items before confirming the break. Practice using the official tools rather than relying on an imagined interface.

Reconcile Documents Without Inventing a Hierarchy

All supplied facts matter. There is no universal exam rule that a code matrix overrides a scenario narrative or that a structural plan always supersedes the program. Look for explicit revisions, dates or instructions establishing which condition applies. A code-summary label may itself need to be evaluated if the question asks whether it is correct.

For example, if a narrative says timber construction while a plan shows protected steel and a summary says Type IIA, first determine whether the item identifies a revision or asks you to assess an alternative. Do not silently choose whichever fact makes the calculation easiest. In professional practice, document the discrepancy and obtain a coordinated clarification. In exam preparation, learn to distinguish an explicit alternate design from an unresolved inconsistency rather than teaching a fictitious priority rule.

Similarly, a room with 150 fixed seats is not automatically assigned 200 occupants merely because its net area divided by 15 equals 200. Fixed seating and unconcentrated movable seating use different occupant-load rules. Apply the actual seating condition and any other occupied areas that must be included.

Worked Integration: A Small Office Floor

Assume a practice case explicitly gives a 12,000-square-foot gross office area and a separate 900-square-foot net conference room with movable tables and chairs. It directs use of the 2021 IBC factors of 150 gross for office and 15 net for this assembly function. Avoid counting the conference area twice: the 12,000-square-foot office figure is stated here to exclude it.

Office load is $12,000/150=80$. Conference load is $900/15=60$. Combined load is 140. If two exits are otherwise required and equally share the load, each serves 70 people for this simplified distribution. With the qualifying sprinkler and voice/alarm conditions and no applicable exclusion, level-component capacity width is $70(0.15)=10.5$ inches per branch. That does not permit a 10.5-inch door or corridor: the independent component minimum governs. An accessible door generally needs 32 inches clear; the applicable corridor and stair minima must also be checked.

Now suppose the conference room changes to chairs-only movable seating. Its factor becomes 7 net, so $900/7=128.572$, rounded up to 129 occupants. Combined load becomes 209. The change can affect exits, fixture counts, ventilation, acoustics and program area. A seating change is not confined to one line in a code table.

Door Encroachment: Two Different Tests

IBC 1005.7.1 distinguishes a leaf during its swing from a leaf fully open. During the swing, it may not reduce the required width by more than one-half. When fully open, the permitted encroachment is generally 7 inches. Do not reverse these criteria.

Take a corridor physically 48 inches wide with a required width of 44 inches. A leaf that projects 34 inches at an intermediate position leaves only 14 inches. Half of the required width is 22 inches, so that position fails. At fully open, a 4-inch projection leaves 44 inches and satisfies the stated fully-open encroachment check. Passing the fully-open test does not cure failure during the swing. Maneuvering clearances, direction of swing, hardware and any special egress requirements remain separate.

Pace the Actual Form

The division provides 245 testing minutes, not five to seven minutes for every case item in addition to a complete discrete-item budget. A practice budget might reserve 70 minutes for twenty case items while allocating 160 to eighty discrete items and 15 to review. The sum is 245; breaks use the separate allowance. Adjust to your performance and actual questions, and avoid spending so long on one calculation that you lose access to easier items.

Before selecting an answer, check dimensions, units, rounding direction, area boundaries and whether every condition is satisfied. A final result should remain plausible: a gross area smaller than its contained net program, a negative required luminaire count or a magically compliant fifth Type VA residential story should trigger a review of assumptions.

Sources: NCARB Guidelines, 2026 case-study changes, and 2021 IBC Chapter 10.

Decision Check