The Beauty Of Urban Infill by Positive Energy

Live from the Texas Society of Architects 2017 Expo and Convention, we're proud to bring you a series of episodes exploring "the multiple dimensions of beauty" through interviews with some phenomenal architects, builders, and consultants. 

This episode features an interview with Kristen & Michael Padavic of PSW Real Estate. 

PSW Real Estate

PSW Real Estate, LLC is a Texas real estate developer that designs and builds communities of high-quality green homes in urban areas. PSW creates homes that offer proximity to work, school and other important resources while implementing energy efficient construction methods and materials. These key elements promote urban density and conservation, reduce waste, and engender social connectivity.

Michael Padavic

Michael joined PSW in late 2011 to develop and lead the newly created design and planning group within the office as part of an initiative to move the architectural development of PSW Homes in house, an aim for greater efficiency and unified vision.

After achieving a Master in Architecture from Harvard University’s Graduate School of Design, Michael honed his skills working for several small to mid-size firms in Chicago, managing a variety of projects from high-rise residential towers and high-end renovations to school restoration and public libraries. He currently holds architectural licenses in both Illinois and Texas.

Specialties: Single family, multi-family and commercial architecture; Sustainable design; Building Information Modeling (BIM)

Kristen Padavic

Kristen moved her family (with Michael, above) to Austin, Texas to join PSW, and Austin-headquartered urban infill home builder after working in Chicago, IL for nearly a decade.  Over the past several years, her architectural team has grown to nearly ten employees, as the PSW team has grown into multiple markets in Texas and Seattle. The team is comprised of a variety of disciplines, including architecture, civil engineering, construction and sales, that all bring unique expertise to the process of designing urban infill communities.


Special thanks to Bautex Systems for their generous support of our live recorded episodes at the 2017 TxA Expo & Convention. Be sure to stop by their website, learn about their innovative product, and say hello for us.


TxA Positive Energy

Season 3 Reflections | Season 4 Preview by Positive Energy

Pour yourself a hot drink, grab a blanket and sit near the crackling logs for this holiday special episode. We're looking back at the last 3 years and looking ahead to our 4th season of the show. Be sure to check out our end of year survey and submit your ideas for episodes in season 4!

Thank you so much for listening to our show for the last 3 years. We plan on delivering more great episodes in 2018 and hope you'll join us for the ride! 

The Beauty Of Performance by Positive Energy

Live from the Texas Society of Architects 2017 Expo and Convention, we're proud to bring you a series of episodes exploring "the multiple dimensions of beauty" through interviews with some phenomenal architects, builders, and consultants. 

This episode features an interview with Darrell McMaster, a builder from Boerne, TX who runs a company called Sustainable Homes of Texas

Darrel has been building homes for over 40 years. He comes from a family of builders, with three generations still active in the home building industry. He is a Master Builder, proud of his craft, and forward thinking in his application of systems and processes.

Darrel says, “the theory is simple if you have to frame on top of the concrete you set up, or build the cabinets that are attached to the wall that you framed you are going to do it right the first time”. 

He's experienced in production, multi-family and custom home building and endeavoring to show that sustainable homes are not only affordable but possible, not only in custom homes but in production homes, as well as multi-family communities.

Special thanks to Bautex Systems for their generous support of our live recorded episodes at the 2017 TxA Expo & Convention. Be sure to stop by their website, learn about their innovative product, and say hello for us.

Knowing & Using VRF by Positive Energy


Apologies for the inconvenience with the last audio file - it appeared to be fine on our side, but was corrupted in the upload process. We appreciate all the feedback and are so thrilled you couldn't wait to hear more! As requested, a new file has been uploaded on a solid connection. Please let us know if you're experiencing any issues and enjoy the episode! 


Positive Energy has built its success around deeply understanding enclosures and how they interact with mechanical systems. We intimately know the HVAC equipment out there. And it hasn’t been easy to get architects, builders, and installers to adopt a new and “unknown” technology. But that’s exactly what we endeavor to do with each project. And you’ve probably guessed by now that we’re talking about VRF here. 

It’s a big deal. It’s the way our industry is headed. And it’s worth understanding and using on your projects. 

In this second of the two part series on VRF, The Building Science Podcast brings you a whole host of information on VRF systems to help you better know, understand, and implement this technology in your projects with a great conversation between our host Kristof and guest John Chavez. Thanks to the generous support of Mitsubishi Electric Cooling & Heating, we're proud to bring you this latest installment of The Building Science Podcast focused on VRF technology and how to bring it to your projects.

Stucco - (Much) More Than Meets The Eye by Positive Energy

Special Edition - Just Released. Listen and learn why you don't want to miss this event! Coming up next Friday 10/13/2017 here in Austin. 

Join Kristof Irwin and guest experts Matt Carlton and Brian Roeder for lively discussion on the surprisingly rich topic of stucco cladding systems. You'll never look at a stucco wall the same way again.

Special thanks to UltraAire for their generous support.

Symposium Details 

Hosted by: AIA BEC: Austin & RCI, Central Texas
Date & Time: Friday, October 13th, 8:30am-5:30am, registration opens at 8:00am
Location: JJ Pickle Research Center, Commons Conference Center, 10100 Burnet Rd, Austin, TX 78758
Price: Early Bird (unitl 9/15) $150/person, General Admittance (9/16-10/12) $190/person, Day Of (10/13) $225
CEUs: 6.5 LU AIA HSW Credits

Intelligent Environments: Building Science & Predictive Analytics Collide by Positive Energy

Join Kristof for a thought-provoking conversation with Dr. Zoltan Nagy on intelligent environments and how building science principles are guiding predictive analytics to shape the future of building and home operations. As more intelligent buildings emerge, occupant-centric solutions to IAQ issues, mechanical issues, and energy issues can be addressed. 

The Intelligent Environments Laboratory (IEL), led by Prof. Zoltán Nagy, is an interdisciplinary research group within the Building Energy & Environments (BEE) Program of the Department of Civil, Architectural and Environmental Engineering (CAEE) in the Cockrell School of Engineering of the University of Texas at Austin.

The aim of their research is to rethink the built environment and define Smart Buildings and Cities as spaces that adapt to their occupants and reduce their energy consumption.

Graphic Mentioned In The Episode

Zoltán Nagy Graphic

Hitting The Reset Button by Positive Energy

It's time to find the reset button. Time to re-examine our view of what we know about delivering conditioned space to our clients, to ourselves. The upside potential in buildings is staggering. From some vantage points, it's astounding and inexplicable why the very places we live continue to be held in a laggard state of performance relative to what's possible. Our industry transition is held captive to an outdated vision. Without a proper vision, our mission, strategy and tactics are ineffective. 

We are all front line advocates, operating within our spheres of influence. What creates effectiveness is knowing why we are engaged in a particular next action and how that relates to moving the industry and the market forward. Why comes first, then what. Many of us can't effectively advocate for best practices in homes/buildings- not because we don't know what to do. Rather it's because we don't know why we need to do what we want to do. If we don't know why then we can't effectively advocate for change with our project teams and the pent-up transition will continue to move forward at a languished pace; albeit inexorably. In this episode Kristof shares some ideas to help us find our reset buttons, or at least pose the idea that hitting reset is worthwhile. 

reset button

Everything You Never Knew About Earthen Construction by Positive Energy

Join us for a fascinating conversation with Stephen Colley on earthen construction. 

Stephen currently practices architecture and runs his own architecture firm and is a long-time practitioner of green design and sustainable living. From 2010-2012 he served as the Program Manager in Green Initiatives for Palo Alto College in San Antonio developing training courses related to sustainable design and construction.

Stephen also participated in the Alamo Colleges Chancellor’s Council on Sustainability helping to write a new more sustainable policy for the Alamo College District.  The new policy was approved by the Board of Alamo Colleges in August of 2012. In his previous position as the Green Building Coordinator for Build San Antonio Green, he developed the criteria for San Antonio’s residential green building program, Build San Antonio Green, recognized by the National Association of Homebuilders as the Green Building Program of the year in 2009, and served on the Mayor’s (San Antonio, Texas) task force on Sustainable Policy as the City charted a significant shift away from conventional building, development, and transportation policy. Stephen was chosen by the National Association of Home Builders as one of the original stakeholders to write the Green Policy for the organization as basis for their nation-wide residential green building program, National Green Building Standard™.

In 2005, he co-authored the Texas Manual on Rainwater Harvesting for the Texas Water Development Board (3rd edition). The Manual is widely distributed and used as a reference for potable and non-potable rainwater harvesting system publications. He is also the former Chair of the San Antonio Chapter of the American Institute of Architects Committee on the Environment, a LEED® Accredited Professional, and President of Earthen Construction Initiative, a non-profit organization to advance and promote earthen construction. 

Photos Mentioned In Episode

Example of earthen construction.

Example of earthen construction.

Earthen Construction Masonry

Earthen Construction Masonry

Compressed earth block machine.

Compressed earth block machine.

Compressed Earth Block Machine

Compressed Earth Block Machine

Notice the earthen construction building in the background still standing after a huge tornado.

Notice the earthen construction building in the background still standing after a huge tornado.

Note: The city in Yemen referred to as “Manhattan of the Desert” is Shibam, in the Hadramut Valley in Yemen. It is designated an UNESCO World Heritage Site.


Earthen Construction Initiative

With a vision that earthen construction is soon recognized as a mainstream building option, the ECI is a member-supported and donor-supported non-profit organization. The ECI website is not yet active, but 2017 memberships are accepted by a check made out to the “Earthen Construction Initiative” along with your contact information at these categories, Student - $10, General Membership - $25, Professional - $50, Companies - $100, mailed to Earthen Construction Initiative, PO Box 39323, San Antonio, TX 78218

For more information, reach out to Stephen Colley.

IEQ Series - Hearing Architecture & ISQ by Positive Energy

Noise can  have an adverse impact on people in offices, classrooms, hospitals and other commercial buildings (European Agency for Safety & Health at Work, 2005), interfering with their daily activities at work or school and at home. People’s performance levels and ability to concentrate can be negatively affected by noise and it can make it harder for them to share knowledge with one another.Join Kristof in this continuation of our IEQ series as he discusses acoustics and sound quality across the architectural spectrum with Keith Simon and John Poesnecker. 

Be sure to check out this wonderful TED Talk by David Byrne on sound and architecture.

View full lesson: As his career grew, David Byrne went from playing CBGB to Carnegie Hall. He asks: Does the venue make the music? From outdoor drumming to Wagnerian operas to arena rock, he explores how context has pushed musical innovation. Talk by David Byrne.

Efficiency Is Not Enough - The Science Of Sustainability by Positive Energy

How good should the building envelope be? How much energy should a building use? Finding answers require putting the building in context with the complex, interconnected, global networks of materials and resource flows in which they exist. Join Kristof for a wide ranging and slightly geeky discussion w Dr William Braham on systems ecology, exergy, emergy, and why a climax forest is a model for power and efficiency. 

Dr. William W. Braham FAIA is a Professor of Architecture at the University of Pennsylvania, where he served as Chair from 2008 to 2011 and is currently Director of the Master of Environmental Building Design and Director of the TC Chan Center for Building Simulation and Energy Studies. He received an engineering degree from Princeton University and an M. Arch. and Ph.D. Arch. from the University of Pennsylvania, where he has taught since 1988. At Penn, he teaches graduate courses on ecology, technology, and design. At the Chan Center, his most recent projects have been the Sustainability Plan, Carbon Footprint, and Carbon Reduction Action Plan for the University of Pennsylvania.

See more of Dr. Braham's work on his website.

Ducts & Sealing & Health, Oh My! by Positive Energy

In this episode, Kristof interviews Sean and Ian Harris, the owners of a duct sealing company called Aeroseal of Austin in Austin, TX. You'll hear discussion on why duct sealing is such a crucial component of healthy delivered air and energy performance of mechanical systems.

Sean Harris has been developing his interest in residential home construction since participating in a remodel project, certified by Austin Energy’s Green Building Program in 2005. With a degree in business administration, Sean combines his interest in green building and knowledge of business systems. Sean oversees the operations of Positive Energy and including product development, quality control, staffing, and marketing/sales. He is also a certified RESNET energy rater and conducts home performance inspections, energy code tests, ECADS, and HERS ratings.


An Interview With John Semmelhack Of Think Little by Positive Energy

Join Kristof in a wide-ranging discussion of building science topics with consultant John Semmelhack of Think Little

John Semmelhack is the owner of Think Little. He is a Certified Passive House Consultant, a member of the Passive House Institute U.S. (PHIUS) Technical Committee, and is a PHIUS Trainer for the Certified Passive House Consultant and PHIUS+ Rater training programs. He sits on the boards of the Passive House Alliance U.S. (PHAUS) and the Passive House Alliance U.S. – Capital Chapter.

John is also a certified Home Energy Rating System (HERS) rater, a Technical Advisor to builders in the EarthCraft House Virginia green building program, and a BPI-certified Building Analyst. He is a graduate of the Leeds School of Business (no, not that “LEED”) at the University of Colorado at Boulder.

Why VRF Matters by Positive Energy

In this first of a two part series on VRF, The Building Science Podcast brings you a compelling argument for why VRF technology matters and will follow up with an episode about how to consider and utilize VRF technology on your projects. Thanks to the generous support of Mitsubishi Electric Cooling & Heating, we're proud to bring you this latest installment of The Building Science Podcast focused on VRF technology and why it's important.


Humidity, Attics, & Spray Foam, Oh My! by Positive Energy

In today's episode, we are joined by Keith Simon of BES/Terracon and Dr. Allison Bailes of Energy Vanguard to discuss moisture issues associated with the use of spray foam insulation in attic assemblies. There's a little bit of background information on Joe Lstiburek's article called "Ping Pong Water & The Chemical Engineer" that you'll want to check out if you're trying to better understand where this conversation is coming from, as well as a few other Energy Vanguard articles to help wrap your head around it.

We also mention some cool RHT sensors in the show, which you can check out here. Also, be sure to keep an eye out for updates on The Humid Climate Conference 2017 in the new year. Big thanks to Ultra Aire Whole House Dehumidifiers for sponsoring this great conversation.

IEQ Series - Thermal Comfort With Robert Bean (Part 1) by Positive Energy

In the continuation of our Indoor Environmental Quality series, Kristof interviews Robert Bean in a 2 part series on thermal comfort. Robert Bean is an industry leading thinker and engineer. We think you're going to love this interview.  

Robert Bean is president of Indoor Climate Consultants Inc. and director of He is a Registered Engineering Technologist in Building Construction and a Professional Licensee in Mechanical Engineering and provides services related to the design of buildings and indoor environmental quality systems. He serves on numerous advisory boards and technical committees including ASHRAE 6.1, 6.5, 7.4, SSPC 55 and the new ASHRAE Presidential Residential Building Committee.

Big thanks to Risinger & Co. for sponsoring this episode! 

IEQ Series - An Introduction by Positive Energy

This introduction marks the beginning of a series on Indoor Environmental Quality. It's one of the most important topics we can discuss because we're exploring intersections of the inextricably linked fields of health and building sciences. We will discuss the constituent parts of IEQ in detail in hopes that you come away more informed to make better decisions for your clients.

Let Us Know More About You!

Your city would be a better answer than "My bedroom"

Water, Water, Everywhere (In Its Fourth State Too) by Positive Energy

In this episode of The Building Science Podcast, Kristof explores all the great mysteries of water (especially the water you don't see).

The Commonly Known Stages of Water

Pure water is tasteless, odorless, and colorless. Water can occur in three states: solid (ice), liquid, or gas (vapor).

Solid water—ice is frozen water. When water freezes, its molecules move farther apart, making ice less dense than water. This means that ice will be lighter than the same volume of water, and so ice will float in water. Water freezes at 0° Celsius, 32° Fahrenheit.

Liquid water is wet and fluid. This is the form of water with which we are most familiar. We use liquid water in many ways, including washing and drinking.

Water as a gas—vapor is always present in the air around us. You cannot see it. When you boil water, the water changes from a liquid to a gas or water vapor. As some of the water vapor cools, we see it as a small cloud called steam. This cloud of steam is a miniversion of the clouds we see in the sky. At sea level, steam is formed at 100° Celsius, 212° Fahrenheit.

The water vapor attaches to small bits of dust in the air. It forms raindrops in warm temperatures. In cold temperatures, it freezes and forms snow or hail.

But what about this mysterious fourth state? Tune in to find out! 

Also, be sure to check out this psychrometric app to run your own humidity experiments.