How much can a building affect human health—and what happens when occupants become highly sensitive to their environment? In this episode, Steve and Pete are joined by retired building scientist and pulmonary physician Nathan Yost for a thoughtful discussion on Multiple Chemical Sensitivity (MCS) and its relationship to building performance.

Nathan shares insights from decades of experience working with clients dealing with chemical sensitivities, along with more recent medical understanding surrounding pregnancy, hormonal changes, and biochemical sensitivities. The conversation explores where building science intersects with health concerns, how indoor environments can influence occupant comfort, and what building professionals should consider when designing for sensitive individuals.

Steve also shares examples from recent projects where MCS concerns led to major changes in materials, specifications, and interior design decisions. The discussion even ventures into the controversial topic of electromagnetic fields and so-called “dead zones,” highlighting the challenges of balancing occupant concerns with evidence-based building practice.

It’s a fascinating conversation about the overlap between buildings, health, and the limits of what construction professionals can realistically control.

Pete’s Resources:
Helping People with Multiple Chemical Sensitivity
Medical Conditions Building Professionals Need to Know About
Prescriptions for a Healthy House (4th Edition)
NIH – Electric & Magnetic Fields
BuildingGreen – Building Design and EMF

Four listener questions. Four very different building science challenges. One highly technical episode.

Steve, Jake, and Pete tackle a collection of building puzzles that span foundations, roofs, wall assemblies, and moisture management. The discussion starts with expansive soils and why successful construction often depends on engineered foundation systems designed to accommodate soil movement. From there, the crew examines attic radiant barriers, where they work best, and why climate matters when evaluating their performance.

The conversation then shifts to a cold-climate stucco retrofit involving exterior rigid insulation, reinforcing a core building science principle: prioritize the four control layers in the right order—water first, airtightness second, drying potential third, and thermal control fourth. Finally, they unpack the risks of a “diaper wall” assembly, where moisture-sensitive materials become trapped between low-permeance layers, and discuss how weather protection and airtightness can reduce those risks.

A highly technical episode packed with practical problem-solving, building science fundamentals, and real-world application.

Pete’s Resources:

• Post-Tension Slabs for Expansive Soils
• Evolution of Foundation Design for Expansive Soils
• ORNL Thermal Performance Evaluation of Attic Radiant Barrier Systems
• Building America Solution Center – Attic Radiant Barriers
• EPA Moisture Control Guidance
• GBA – Vapor Profiles Help Predict Whether a Wall Can Dry

Do certifications, standards, and professional credentials actually lead to better buildings—or just more paperwork? Steve, Jake, and Pete tackle one of the more uncomfortable questions in the building industry: why so many standards fail to consistently produce better outcomes in the real world.

The conversation ranges from ASTM standards and manufacturer testing to architectural credentials and industry certifications, questioning where standards genuinely help—and where culture, habits, and resistance to change become the bigger obstacle. Steve makes the case that the industry’s biggest challenge may not be technical at all, but cultural.

The crew also digs into one of Steve’s standout ideas: “chase friction.” Instead of accepting inefficient details, weak processes, or recurring failures, the goal should be to constantly look for the points of resistance that reveal where buildings can improve.

It’s an opinionated discussion with a few disagreements along the way, but the central takeaway is clear: meaningful progress only happens through rigorous education—for both building professionals and clients alike.

Pete’s Resources:

• Treasure of the Sierra Madre clip
• ISO Construction Quality Standards
• Construction Education & Certifications
• Chasing Friction Article

Can ZIP-R panels work on a roof—and should they? Steve, Jake, and Nick Sabol from Huber’s Technical team dig into a topic that’s getting a lot of attention in the field.

This episode breaks down the full set of considerations behind putting insulated sheathing on the roof deck: structural loading, fastening and shear, hygrothermal behavior, condensation risk, and long-term durability. The crew looks at where the idea makes sense, where it doesn’t, and what you need to understand before trying it on a real project.

It’s a detail-heavy conversation that connects theory to field conditions—exactly where most “good ideas” succeed or fail. And for Pete’s top resource on this one? Call Steve.

Pete’s Resources:

• ICC-ES Report 1473
• Roofs & Attics: The Building Science of “the Lid”
• Huber Technical Support: techquestions@huber.com

Do wildfire zones actually change how rainscreens should be detailed—and where does conventional thinking fall short? Nick Sabol from Huber’s Product Engineering team is back with Steve and Pete to continue the deep dive into wall details that actually work.

This episode focuses on rainscreen strategies in wildfire-prone areas and challenges the assumption that every risk requires a completely different assembly. The discussion also highlights Steve’s perspective on using materials like ZIP sheathing in unconventional ways—prioritizing performance and continuity over tradition when it makes sense.

From fire exposure considerations to air barrier continuity, the conversation connects real-world risk with practical detailing decisions. It’s a continuation of the Part I discussion, with a sharper focus on where building science meets evolving conditions like the Wildland Urban Interface.

Pete’s Resources:

• ICC Harmathy’s Ten Rules
• US Fire Administration – Wildland Urban Interface
• IBHS External Sprinklers for Wildfire Defense
• Build Show – Air Barrier Continuity (Wall to Ceiling)
• Build Show – Air Barrier Continuity (Ceiling)

What are the most critical wall details for managing water and air—and where do builders get them wrong? Nick Sabol from Huber’s Product Engineering team joins the crew for a technical deep dive into exterior wall assemblies that actually perform.

Pete, Jake, and Nick focus on two of the most failure-prone areas in construction: bottom-of-wall-to-foundation connections and window rainscreen detailing. The discussion breaks down how to properly manage bulk water, maintain continuous air control, and integrate systems so they work together instead of against each other.

Along the way, they introduce RAINA (Rainscreen Association in North America) and highlight why rainscreen strategies are becoming essential for durability across climates. It’s a detail-heavy episode with practical takeaways for builders, designers, and anyone serious about building enclosures—plus, for better or worse, no Dad joke this time.

Pete’s Resources:

• Huber ZIP System Bottom-of-Wall Details
• Above-Grade Foundation Wall Waterproofing (GBA)
• Huber Technical Support: 1.800.933.9220 | techquestions@huber.com
• RAINA (Rainscreen Association of North America)
• Must-Know Window and Door Flashing Details

How much load can insulation actually carry—and are we over-engineering residential buildings without realizing it?

This episode goes deep into the structural and thermal realities behind common building materials. The crew breaks down compressive loading on rigid insulation, long-term creep behavior, and how these factors influence slab and foundation design. From there, the conversation expands into thermal bridging challenges in wood and concrete assemblies, and how innovative framing systems like EcoSmart and Tolko aim to improve performance.

Along the way, they question a core assumption in residential construction: are we solving problems that don’t actually exist? The discussion highlights where engineering matters—and where it may be overkill.

And in true UnBuild It fashion, Steve closes things out with an unexpected design tangent involving beehives.

Pete’s Resources:

• Compressive Creep Behavior of EPS Geofoam
• BSI-059: Slab Happy
• BSI-118: Concrete Solutions
• EcoSmart Studs
• Tolko Wall Framing

Climate drives building performance. In the first episode of a three-part series, Pete, Steve, and Jake explore why climate matters so much in building science.

Steve kicks off the discussion with a simple analogy: Would you pack the same suitcase for Minneapolis in February, Honolulu in March, and New Orleans in July? Of course not. Buildings work the same way. Design decisions about insulation, vapor control, air barriers, and drying potential all depend on where the building lives.

The conversation walks through how climate zones influence building enclosure strategy and why national research from the Building America program has shaped modern high-performance construction. And of course, no climate discussion would be complete without Joe Lstiburek’s “Perfect Wall,” one of the most influential concepts in applied building science.

This is the first of three episodes exploring how location shapes building design. Next up: Site and Extreme Events.

Pete’s Resources:

• Building America Solution Center – Climate search
• PNNL US Climate Map Guide
• BSC Enclosures That Work
• BSC BSI-001 The Perfect Wall