Why PPD Is the Hardest ARE Division
Project Planning & Design (PPD) has the lowest pass rate of all six ARE divisions - consistently around 50–56%. It earns this reputation for a simple reason: it covers more technical breadth than any other division. PPD tests structural systems, mechanical systems, electrical systems, plumbing, building envelope, sustainability, accessibility, and how all of these integrate during the design phases of a project.
Candidates who struggle with PPD typically fail not because of one weak area, but because they underestimated the depth required across all areas. The good news: PPD rewards candidates who understand systems conceptually, not those who memorize formulas. You need to know how things work and why, more than you need to calculate exact values.
PPD Exam Format
PPD is one of the two 120-question divisions (alongside PDD), with a 4 hour 40 minute time limit. The extra length compared to other divisions reflects the breadth of content tested. Question formats include multiple choice, check-all-that-apply, case studies, drag-and-place, and hot spot.
Structural Systems
Structural content is the area most candidates feel least confident about, and it's one of the largest content areas on PPD. Use the Structural Systems Cheat Sheet as a quick reference while studying.
Load Types and Load Paths
Know the six load types: dead, live, snow, wind, seismic, and thermal/movement. Understand how loads travel from the roof through floor systems, beams, columns, and foundations to the ground. NCARB tests load path identification in building sections and plans.
Lateral Systems
Lateral resistance is heavily tested. Know the difference between:
- Moment frames - Resist lateral loads through rigid beam-column connections. Flexible, allow open plans.
- Shear walls - Resist lateral loads through stiff wall panels. Most common in wood and concrete construction.
- Braced frames - Diagonal bracing members resist lateral loads. Economical in steel construction.
- Diaphragms - Horizontal elements (floors and roofs) that collect and distribute lateral loads to vertical elements.
Structural Systems by Material
For each structural material, know the typical spans, advantages, and applications:
- Wood light frame - Repetitive framing, stud walls, engineered lumber (LVL, PSL, glulam)
- Steel - Long spans, W-shapes, open web joists, moment frames and braced frames
- Concrete - Cast-in-place (one-way/two-way slabs, flat plates, waffle slabs) and precast
- Masonry - Load-bearing CMU, reinforced masonry, cavity walls
Foundation Types
Know when to use spread footings, mat foundations, pile foundations (friction vs. end-bearing), drilled piers (caissons), and grade beams. Foundation selection depends on soil bearing capacity, loads, and site conditions.
Mechanical Systems (HVAC)
System Types
Know the operating principles and applications of:
- VAV (Variable Air Volume) - Central air handling with variable flow to zones. Most common in commercial office buildings.
- Fan coil units - Distributed units with chilled water coils. Common in hotels and residential.
- VRF/VRV (Variable Refrigerant Flow) - Multiple indoor units served by one outdoor unit. Efficient for mixed-use buildings.
- Heat pumps - Air-source and ground-source. Understand COP (coefficient of performance) and when ground-source is justified.
- Radiant systems - Radiant floor heating and chilled beam cooling. Used in high-performance buildings.
Ventilation and Indoor Air Quality
ASHRAE 62.1 governs ventilation rates for commercial buildings. Know the ventilation rate procedure and that outdoor air requirements are based on occupancy and floor area. ASHRAE 170 governs ventilation in healthcare facilities - know minimum outdoor air ACH requirements for operating rooms (4 ACH outdoor air, 20 ACH total) and other healthcare spaces.
Psychrometrics Basics
Understand the psychrometric chart conceptually: dry bulb temperature, wet bulb temperature, relative humidity, dew point, and enthalpy. Know that sensible heat affects dry bulb temperature while latent heat affects moisture content.
Electrical Systems
Distribution Basics
Power enters a building from the utility transformer, passes through the main service entrance panel, and is distributed to sub-panels serving individual floors or zones. Know the difference between single-phase (residential) and three-phase (commercial) power, and that most commercial buildings use 277/480V three-phase distribution with 120/208V at devices.
Lighting
Know foot-candle requirements for different space types. Understand the difference between illuminance (foot-candles, lux) and luminance (brightness). Know that ASHRAE 90.1 sets lighting power density (LPD) limits by space type - a key sustainability compliance requirement.
Emergency Power
NFPA 110 covers emergency and standby power systems. Know that Level 1 systems (hospitals, life safety) must transfer to emergency power within 10 seconds and maintain a minimum 4-hour fuel supply.
Building Envelope
Thermal Performance
ASHRAE 90.1 sets prescriptive requirements for envelope U-values and R-values by climate zone. Know that U-value is the reciprocal of R-value (U = 1/R), and that lower U-values indicate better insulation performance. Understand thermal bridges and how structural elements conduct heat through the envelope.
Moisture Control
Know the difference between vapor barriers (impermeable, block moisture diffusion) and air barriers (resist air movement). In cold climates, the vapor barrier goes on the warm side of the insulation. Understand the dew point concept and why condensation forms within assemblies when moisture reaches the dew point temperature. See the Building Envelope Cheat Sheet for a quick reference on assemblies and performance metrics.
Glazing Performance
Know U-value (thermal transmittance), SHGC (solar heat gain coefficient), and VT (visible transmittance). In hot climates, low SHGC reduces cooling loads. In cold climates, higher SHGC on south-facing glazing can reduce heating loads through passive solar gain.
Sustainability and Green Design
PPD tests sustainability concepts broadly - passive design strategies, LEED v4 credits, energy modeling basics, and daylighting principles. Key topics:
- Passive solar design - building orientation, thermal mass, overhangs
- Natural ventilation - cross-ventilation, stack effect
- LEED EA (Energy & Atmosphere) credits - energy performance optimization
- ASHRAE 90.1 as the energy code baseline
- Net-zero and net-positive energy concepts
Study Strategy for PPD
Allocate more time. Most candidates need 8–12 weeks for PPD versus 4–6 weeks for easier divisions. Do not shortchange this division.
Study systems conceptually first, formulas second. NCARB tests whether you understand how systems work, not whether you can calculate exact values. Learn the concepts before memorizing equations.
Use diagrams and sketches. Draw load paths, HVAC system diagrams, and envelope assemblies by hand. The act of drawing reinforces spatial understanding of systems.
Take PPD last. The structural and MEP knowledge from PPD overlaps with PDD, and the professional context from PcM/PjM helps you answer scenario questions correctly. Taking PPD last gives you the fullest preparation.
AREprep for PPD
AREprep's PPD content includes 400 original flashcards covering all major systems, 30 timed mini exams, and 3 full-length 120-question simulations written to match the difficulty and format of the actual NCARB exam. The full exam simulations are particularly valuable for PPD because the sheer length (4 hours 40 minutes) is itself a challenge that only timed practice can prepare you for.