Building Performance & Science Series
This is a DRAFT framework for an 11-part monthly FC BS+Beer series to accompany a parallel affordability series.
We intend to cover a full Building Performance Framework:
purpose and outcomes → environmental conditions → loads and stressors
→ failure mechanisms → enclosure and mechanical strategies.
Each session ideally will include:
- Core principles
- Practical applications and design implications
- Real-world examples of building failures related to that topic
Session Overview
1 — Purpose of a House: Desired Performance Outcomes
A house as an environmental separator and performance system.
- Safety (fast threats: crushing, impact, electrocution, fire, CO, falls, burns, cuts, unauthorized entry)
- Health (slower threats: inhalation, ingestion, contact exposure to contaminants)
- Comfort (thermal, humidity, acoustic, visual)
- Affordability (acquisition, operation, maintenance, modification, deconstruction)
- Durability and predictable, manageable aging
- Resilience during outages, failures, extreme events
- Function & usability
- Attractiveness
safety incidents, IAQ issues, comfort complaints, hidden durability failures.
2 — Environmental Conditions & Stressors
The external environment the building must withstand.
- Weather: precipitation (rain, snow, hail, sleet), wind, temp. extremes, thermal cycling, solar exposure, humidity cycling
- Airborne substances: biological (spores, etc.), chemical (off-gasses, etc.), particulate (smoke, dust, PM)
- Biological ecosystem: insect pressure, vermin prevalence
- Flood exposure, drainage, water table
- Soil conditions: chemistry (corrosivity, salinity), mechanics (shrink/swell, settlement, PVR)
- Seismicity
wind-driven rain intrusion, UV degradation, insect damage, freeze–thaw spalling, foundation settlement or heave.
3 — Loads on Buildings & Occupants
How environmental conditions turn into forces and stressors.
- Mechanical: gravity (dead/live/snow), hydrostatic/dynamic, wind pressure, soil movement, seismic, impact, vibration
- Moisture: bulk water, capillary action, vapor diffusion, surface wetting
- Airflow/pressure: wind-driven, stack effect, mechanical (fans), soil-gas pressure
- Chemical/electrochemical: oxidizing, corrosive, reactive, galvanic environments
- Radiation: UV photolysis, infrared heating, visible-light photodegradation
- Thermal: expansion/contraction, thermal shock, freeze–thaw cycling
- Combustion exposure: flames, convective and radiant heat, smoke/soot, ember attack
- Human-caused loads: forced entry, deliberate impacts, vandalism, arson
- Respiratory: biological aerosols, combustion gases (CO, NO2), soil gases (radon, VOCs), particulates, VOCs
- Somatosensory: air temperature, radiant temperature, odors, off-gassing, smoke
- Auditory: acoustic loads (noise)
- Visual: light, glare, darkness
- Cross-cutting: humidity extremes, contact with irritant or harmful substances
wind uplift failures, bowed or cracked foundations, radon entry, chronic thermal discomfort from radiant asymmetry or humidity.
4 — Failure Mechanisms & Failure Modes
How materials and systems degrade and how that shows up as building failures.
- Mechanical: cracking/fracture, deformation, creep, mechanical fatigue
- Biological: rot, mold, insect material consumption, burrowing, gnawing, biofouling
- Thermal: embrittlement, softening/melting, pyrolysis, thermal fatigue
- Chemical: corrosion, volatile loss, oxidation, solvent attack, chemical swelling
- Photo-oxidative: UV polymer breakdown, UV-driven surface oxidation, coating breakdown
- Structural: fracture, buckling, excessive deflection, shear failure, foundation movement
- Envelope: water intrusion, air leakage, vapor condensation, drying failure
- Material: spalling, delamination, warping, abrasion, embrittlement, crazing
- Connection: fastener withdrawal, fastener shear, adhesive bond loss
- System: control failures, HVAC failures, plumbing leaks, electrical faults
- Soil: shrink/swell deformation, erosion and loss of support
mold from wetting/drying imbalance, corroded fasteners, UV-damaged WRBs, delaminated claddings, system breakdowns.
5 — The House as a System: Heat, Air, Moisture Interactions
Most failures result from interactions of heat, air, and moisture.
- Coupling of heat, air, and moisture flows
- Pressure regimes inside and outside the enclosure
- Why improving one element (e.g., tighter envelope) affects others (ventilation, moisture)
hidden condensation behind finishes, moisture cycling fatigue, depressurization pulling soil gases or flue gases into the house.
6 — The Four Control Layers: Water, Air, Vapor, Thermal
The main tools for controlling flows and preventing failures.
- Purpose and hierarchy of water, air, vapor, and thermal layers
- Placement, continuity, and alignment across assemblies
- How control layers relate to loads and failure modes
misaligned WRB and air barrier, reversed vapor profile, thermal bypasses creating cold surfaces and condensation risk.
7 — Bulk Water & Light Control: WRBs, Cladding, Roofing
Bulk water is the #1 cause of building failure.
- WRB selection and installation as drainage planes
- Cladding systems, rain screens, and drying gaps
- Roofing as primary weather protection
- Solar and UV exposure as long-term stressors on materials
flashing errors, capillary wicking at siding and trim, moisture trapped behind cladding, UV-brittled membranes, siding rot.
8 — Air Leakage & Vapor Control
Air movement carries far more moisture than diffusion.
- Air barrier strategies, materials, and common leakage sites
- Blower-door testing concepts (diagnostic and compliance)
- Vapor diffusion, vapor retarders and barriers, smart membranes
- Climate-appropriate vapor strategies and drying paths
attic or roof condensation, mold behind polyethylene, wall rot from exfiltration in cold climates, summer inward vapor drive behind low-perm interior finishes.
9 — Heat Flow, Thermal Bridging & Condensation Management
Thermal control is also moisture and durability control.
- Heat transfer modes and effective vs nominal R-value
- Thermal bridging through framing and structural elements
- Continuous insulation and thermal breaks
- Dew point management and locating condensation planes safely
cold sheathing rot, condensation at framing members, ice dams, persistent cold spots and comfort complaints.
10 — Assemblies: Walls, Roofs, Transitions, Windows & Doors
Bringing the control layers and performance goals together in real assemblies.
- Wall and roof assemblies: pros/cons, drying strategies, risk management
- Vented vs unvented roofs and when each is appropriate
- Integrating windows and doors with WRBs and air barriers
- Critical transitions: slab-to-wall, wall-to-roof, decks, balconies, penetrations
window corner leaks, missing kick-out flashing, unvented roof moisture buildup, transition leaks at decks and balconies.
11 — HVAC, IAQ & Mechanical Integration
Mechanical systems as part of the building performance system, not an afterthought.
- Ventilation strategies: balanced, exhaust-only, supply-only
- Filtration and humidity control as health and durability tools
- Right-sizing loads and distribution for comfort and efficiency
- Interactions between mechanical systems and the enclosure (pressure, moisture, contaminants)
depressurization and backdrafting, duct leakage causing comfort and moisture problems, poor IAQ from inadequate ventilation, oversized/undersized systems.