Design & Construction Resources
How to Seal Air Barrier Penetrations
In even the tightest building envelope there will always be intentional holes in the air barrier. Common penetrations are plumbing pipes, vent pipes, wire penetrations, and outlet boxes. 475 offers...
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How To Use The AEROFIXX Spray And Seal Airtightness Tool
The AEROFIXX spray and seal application tool makes quick work of difficult and hard-to-reach air sealing jobs. It connects to standard compressors to easily apply liquid-applied airtight membranes anywhere from...
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Passive House Goes Prefab
Growing their media offerings, the team at Passive House Accelerator have released the first edition of their magazine, entitled “Passive Goes Prefab”. It chronicles the Prefab companies working to turn...
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Four Key Reasons for Building with a Vented Rainscreen
When looking for the essential nature of construction, the architect Louis Kahn famously said: 'What do you want, brick?' Today, in looking at the nature of high-performance building enclosures, we...
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5 Tricks of the Trade For Thick, Dense-Packed Walls Behind Pro Clima Membranes
With contributions by Matthew Brennan, National Sales Manager at Thermocell; Jesse Matthews, Quality Control at RDH (formerly carpenter at The Fourth Pig Green and Natural Construction). At 475, a large...
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The Ten Golden Rules for Foam-Free Flat Roofs
When insulating a flat roof wood structure, 475's goal, as always, is to do it in the most healthy, structurally sound, durable, and ecologically friendly way—achieving truly high performance. This...
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The Double-Stud Wall Simplified: Low Cost, High Performance
Low Cost High Performance Simplify. The double-stud wall is a well established method for creating a very economical, durable and high R-value assembly in new construction - and is one...
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How To Prepare For High Performance Windows
Windows might make you nervous. They're often big and heavy, yet fragile. And in a high performance building, windows are the most expensive components. But that investment in great windows...
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An Interior Air Barrier Does It Better
Ever tempted to wear your underwear over your pants? Neither are we! But when it comes to buildings, we’re seeing a lot of common practices that are equally backwards. It...
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How To Make that Old Leaky Masonry Row House Airtight
The historic masonry row house (or "brownstone" as we call it here in New York) is a common contributor to the character in many cities and small towns. When renovating...
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How to Keep Floor Beams Where They Should be - Inside the Airtight Layer
You know the air barrier must be continuous, without interruption around the entirety of the conditioned space - inboard of the main insulation layer, thereby keeping the conditioned air within...
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5 Steps For Sealing Intentional Holes in Your Air Barrier
A continuous air barrier is one of the defining design details of Passive House and high-performance building. The red line that many of us draw on blueprints to indicate the...
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Flanged Window Install Guide for High Performance Enclosures
Sequencing For Making Flanged Windows Airtight Flanged windows are ubiquitous in American construction. As we push toward higher levels of enclosure performance;- with increased insulation levels, airtightness and vapour control;-...
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Double-Stud Walls: WUFI Pro Shows INTELLO is Key
New Mold Growth Index and Safe Double-Stud Walls Double-stud walls have been regarded as a simple to build, low-cost, high-performance solution since the energy crisis in the 1970's. (See our...
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Common Air Barrier Failures and How to Avoid Them
Top Ten *NO* Eleven Air Barrier Failures 1. It's not continuous! Mind the gap! The mother of all failures. You don't have an air barrier if it's not continuous- it...
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How to Stay Airtight When Buildings Move
Buildings move. Ensuring that your air barrier is resilient to movement is crucial to ensuring the longevity and performance of your building. Unless you're building a structure using just one...
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4 Hurdles to Hitting Passive House Performance & How to Overcome Them
4 Hurdles to Hitting Passive House Performance & How to Overcome Them Passive House performance is the future of building. As with any trip there are obstacles. Yet professionals new...
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Vapour Venting An Unvented Roof: Added safety by adding a vapour diffusion port
"Classic Ridge Rot" documented by the Building Science Corporation in Alaska Planes can fly safely with one engine. And you can keep your pants up with just a belt. But...
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How To Stay Airtight Without A Service Cavity
Intro / Caveat As you may know, 475 recommends you use a service cavity on the interior of high performance, airtight building envelopes. We've enumerated the values of service cavities...
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Airsealing Beam Penetrations
Joist Connections Add Up Plaster is a great airtightness solution for party walls. But connections to the joists need to be addressed. This Ecostruct project achieved 0.23ACH50 after this plaster...
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