May 4, 2018

Airtight Wright: Using INTELLO to Restore an Architectural Relic

UPDATE: Award-Winning Restoration In May 2018 Docomomo US, a non-profit organization dedicated to the documentation and conservation of the modern movement, announced the 13 recipients of the 2018 Modernism in America Awards, which included Lurie House. The thoughtful renovation of Lurie House led the jury to award Kaneji Domoto a Citation of Merit stating, “this is […]

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April 26, 2018

Smart Vapor Control, Magical Thinking and Goldilocks

Be sure to protect your building for its entire lifetime. In an endurance test, it’s critical to have capabilities in reserve to handle the unexpected: And the life of a building enclosure is an endurance test. The greatest threat to a building’s longevity is moisture damage. Consequently, moisture risks must be mitigated by maintaining a […]

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March 1, 2018

Introduction to INTELLO

The keystone to long-lasting airtightness and vapor control.   The INTELLO membrane, manufactured by Pro Clima of Schwetzingen Germany, is the state-of-the-art interior vapor control and air-tightness membrane for cold and mixed climates. It is an intelligent membrane that changes permeability in a range from <0.13 perms in winter to 13.2 perms in summer depending […]

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February 13, 2018

In the PHI Lab and In the Field: INTELLO Tests Tightest

Pro Clima’s INTELLO airtight system proven by Certification of the Passive House Institute and at the University of Northern British Columbia. Airtight Passive House and high-performance building enclosures help make more comfortable, healthy and energy efficient buildings. The tighter the better. It can’t be repeated enough. It follows that to make an enclosure airtight, we must use airtight materials. Ergo, the tighter […]

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September 21, 2017

Building In Fall & Winter?  INTELLO Will Protect You

You’re building a high-performance, low energy building – maybe even a Passive House. What’s the Problem? You started construction in the summer, but by late Fall or Winter the finishes are being installed and the indoor relative humidity (RH) is high – reaching 90%.  You know the vapor drive is going out and the wood […]

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June 29, 2017

Path Toward Perfection: A Beautiful High-Performance Home in Egremont, MA

Beauty We often talk  about the extensive benefits of high-performance buildings: lower energy costs, more durable structures, reduced maintenance requirements and healthier interior environments.  High-performance strategies can improve the lives of building owners and occupants. Beauty is not as quantifiable perhaps, but it can bring delight to life.  And there is nothing more delightful than working on projects […]

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June 14, 2017

Do More With Less: Your Dense Pack Netting Should Multitask

Dense pack insulation is a great way to insulate – whether it be cellulose, wood fiber (Thermofiber by GUTEX), sheeps’ wool (by Havelock wool), or fiberglass. It can guarantee gap-free thermal protection, filling all the nooks and crannies. But typical mesh-netting systems for dense pack insulation like Insulweb do one – and only one -thing: contain […]

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April 14, 2017

A Smart Enclosure Starts with Smart Walls: Green High-Performance Done Right For Our Sustainable Future

For thousands of years, buildings were made with a keen regard for nature and historically, building science was intimately attuned to natural phenomenon. Then, the 20th-century builders, with giant resources of energy and rapid scientific advancements tried to conquer the vagaries of nature. Natural solutions were ignored – they made up, down, and down, up – if they felt like it. And […]

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February 14, 2017

Top Ten *NO* Eleven Air Barrier Failures

1. It’s not continuous! The mother of all failures. You don’t have an air barrier if it’s not continuous – it won’t be air tight. Many of the items that follow below are all causes of discontinuity. Like a balloon or a submarine – the continuity of the airtight layer must be sacrosanct. While discontinuity can […]

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September 9, 2016

Vapor Venting An Unvented Roof: In Praise of Belts and Suspenders

Planes can fly safely with one engine. And you can keep your pants up with just a belt. But if you’re looking to be protected from fools, then adding suspenders to the belt might be what sets you free. So while we’ve previously outlined the essential importance of inboard airtightness and vapor control and have specifically written […]

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May 23, 2016

The Double-Stud Wall Simplified: Low Cost, High Performance

Simplify. We know pushing standard code-minimum construction toward high performance is complicated. So we’re always looking for ways to simplify – to simultaneously reduce cost while optimizing efficiency and occupant comfort. [See our recent post on Breaking The “Upfront Cost Barrier”.] The double-stud wall is a well established method for creating a very economical, durable and […]

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May 2, 2016

The Returns From Indiana Are In: 0.4 ACH50 For The Win!

Cruz, Clinton, Trump, Sanders…Warkentien? Dave Warkentien lives in Indiana and recently earned winning numbers: 0.4 ACH50.   He also got winning returns on power usage: at negative 457kWh for the first three months of 2016 (and that’s after accounting for two electric cars usage of 655kWh). We haven’t seen numbers like that since the SURE House won the DOE Solar Decathlon. The wins […]

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February 11, 2016

INTELLO & DB+ Approved by DIBt for Use in Unvented Hot Roof Assemblies

The highly respected Federal Agency Deutsches Institut für Bautechnik (DIBt)* has certified INTELLO PLUS and DB+,  per German testing standard DIN68800-2, for use in unvented assemblies with vapor closed exteriors.  Such assemblies include unvented metal roofs, green roofs and gravel roof flat roofs, as well as vapor closed pitched roofs with asphalt shingles, EPDM, TPO etc.  With this certification these materials […]

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January 29, 2016

INTELLO PLUS Resource Library

INTELLO PLUS is revolutionizing the North American construction industry. No other product provides the same level of vapor control, airtightness and resilience for your high performance projects. We also know that many builders and architects out there are looking to increase their understanding of INTELLO PLUS – from how it works to how to install it. (more…)

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October 8, 2015

Yes, Unvented Roof Assemblies Can Be Insulated With Fiberglass – A WUFI Post

And Not Just In Climate Zones 2B & 3B: Cold Climates Too A post on August 21st, 2015 on, Martin Holladay asked the question, Can Unvented Roof Assemlies Be Insulated With Fiberglass?  Martin’s post focuses on the marketing of Owens Corning’s ProPink Unvented Attic Insulation System.   The Owens Corning system is only allowed by code in zones 2B […]

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September 9, 2015

Pro Clima’s Best-Sellers Achieve Declare Label

Product Transparency Comes Into Focus For INTELLO Plus, TESCON VANA, and TESCON Primer RP 475 has achieved the Declare building product transparency label for our best-selling tapes and membranes. The Declare label aims to transform the marketplace through transparency and open communication by serving as a voluntary ‘nutrition-label’ for building materials. Declare integrates with the Living Building […]

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August 10, 2015

INTELLO Plus transforms assisted living facility in Mashpee, MA

  475 High Performance Building Supply is proud to be the supplier of INTELLO Plus intelligent vapor retarder membrane and other Pro Clima products for an Assisted Living Facility in Mashpee, MA. According to their website, “Bridges® by EPOCH at Mashpee continues our commitment to providing the highest-quality senior living experience and care exclusively for those with Alzheimer’s disease […]

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July 14, 2015

Why The Vapor Curve Matters

How vapor variable materials stack up when it comes to mileage and protection Intelligent membranes, or smart vapor retarders, can help prevent condensation in enclosure assemblies (walls and roofs) in winter, while allowing inward diffusion in summer. This transformation is important to assure the safety of an insulated assembly, by increasing its drying reserves so it can cope with (unforeseen) moisture — both into […]

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May 7, 2015

Project Spotlight – INTELLO Plus with “Integrated Service Cavity” in Leicester VT

One of the most popular high performance walls is the double stud wall. Its appeal lies with the fact that it creates a good thermal break between two simple-to-build wood frame walls. It can also be economical, even before considering long-term energy savings. The open cavities are typically dense-packed with blown-in cellulose or fiberglass for insulation values ranging from R-30 to R-50 […]

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April 2, 2015

Why New Yorkers Love Passive House

This video speaks for itself. We featured this project in a previous video – 475 On-Site: Historic Brownstone Passive House Retrofit in Brooklyn, NY. It is in process to receive EnerPHit certification with architect, Jane Sanders, and builder, Build With Prospect. So how does this work? Airsealing and insulation. These two measures increase comfort, while drastically reducing energy and outside […]

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January 16, 2015

Hanover, NH: Dartmouth College Dormitory Retrofit

Countless historic masonry buildings dot the American landscape, a large number of them falling under some form of aesthetic scrutiny prohibiting exterior insulation. The only option to make these buildings energy efficient is to insulate them on the interior. 475 High Performance Building Supply works with architects and builders to insulate these walls safely from the interior – considering moisture drive, bulk rain water […]

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December 30, 2014

Press Release: 475 Granted Exclusive Pro Clima Distribution in Canada

FOR IMMEDIATE RELEASE Building Airtightness Specialists Offer New Solutions to Canadian Builders German Airtight Building Leader Grants Exclusive Canadian Distribution to 475 High Performance Building Supply New York City – December 30, 2014 475 High Performance Building Supply (475), a building materials company based in New York City, is offering a new solution for building […]

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November 5, 2014

West Coast Pro Clima Tour Recap

Pro Clima founder, building scientist, and INTELLO inventor Lothar Moll along with Jens Lüder Herms, head of Pro Clima R&D, toured the west coast in mid-October with me (Floris) to present information, see common construction practices, and analyze how to improve the quality of construction. This trip also coincided with 475 opening of our west coast warehouse, which will […]

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September 18, 2014

Middlesex VT: Foam-free, WUFI-verified, and OSB-free high performance

The town of Middlesex, Vermont, located just north of Montpelier, has put itself on the high performance building map. Leading the way is the new “Whitchurch Passive House Cottage” – not only in terms of energy efficiency (Passive House certification is in the works), but also as a unique and adventurous example of “form follows function”. The project […]

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March 25, 2014

5 Reasons Why Airtight Drywall Is Obsolete

After perhaps keeping the rain out, airtightness is the most important thing we can do to make our buildings energy efficient and comfortable.  That’s a building science fact.  A fully functional air barrier is fundamentally important to the proper functioning of the building.  Consequently we should take necessary steps to ensure that the airbarrier works, […]

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February 19, 2014

475 Does WUFI®: Mold Potential and Historic Masonry Retrofits in Climate Zone 6 (Burlington, VT)

A key piece of the puzzle as we decarbonize our building stock is successfully retrofitting historic masonry buildings to high performance standards that provide energy efficient operation and comfort while preserving the structural integrity of these timeless buildings for future generations. We have written often that preservationists and energy efficiency advocates need not be in opposition, […]

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January 13, 2014

Keeping Sheathing Dry in High-R Double-Stud Walls – a WUFI study

(The is the second installment in the 475 blog series 475 Does WUFI. ) Double-stud walls have become a popular and cost efficient way to build well-insulated envelopes: two 2×4’s spaced apart easily makes a R-40+/10.5″ thick wall. Such walls also include a thermal break and can be insulated with densepacked cellulose or fiberglass, both […]

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December 12, 2013

Tight Historic Masonry Rowhouse Renovation by Caliper Studio

On Prospect Avenue in Brooklyn, NY, Caliper Studio‘s gut renovation of a brick brownstone rowhouse used what has become the typical Passive House project approach: very good triple-pane glass windows, thermal bridge free LAMILUX skylights, and a interior insulation with cellulose and Pro Clima INTELLO membrane as the smart vapor retarder and air barrier. We […]

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November 26, 2013

The INTESANA Primer: The DER Solution

The INTESANA membrane, manufactured by Pro Clima of Schwetzingen Germany, is the state-of-the-art ingredient for Deep Energy Retrofit (DER) interior vapor control and air-tightness in cold and mixed climates. It is an intelligent membrane that changes permeability from 0.17 perms in winter weather to over 13 perms in summer, depending on the relative humidity around it. This intelligent range of […]

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