August 16, 2017

Hooray for Double Standards: Passive House + LEED Platinum in Quebec

Sarah Cobb and William Murray of Construction Rocket Inc. are dedicated to bringing about radical change in the building industry. As Passive House Certified Builders, they are committed to ensuring energy performance, even in harsh, challenging climates. And their recently completed Springhouse in Abercorn, Quebec, proves that Passive House design and construction doesn’t have to compromise […]

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August 8, 2017 unnamed

Ventilation That Keeps Affordable Housing Occupants & Owners Happy

The Presentation 475 gave a presentation on minimizing mold risk in high-performance buildings at a Maryland Affordable Housing Coalition event in Baltimore recently. In the audience were a number of affordable housing developers. During the talk we discussed the importance of airtightness, thermal-bridge-free construction, and good ventilation. The response from the housing developers, who were […]

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July 5, 2017 Loose-fill or batt, Havelock Wool is a natural, comfortable and effective installation solution.

IDEAL Window Installation – Improving Best Practices

You bought high-performance windows, but is the install going to complement their performance or detract from it? The enclosure insulation, airtightness and moisture control should be continuous. But too often where the window frame meets the building we see breaks in insulation, air leaks and vapor traps – all setting the stage for discomfort, inefficiency and […]

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June 29, 2017 _DSC3103

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 cellulose_with_INTELLO-200px

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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June 12, 2017 roofdiagram

INTELLO Responds To High Enclosure Moisture Levels – Proof Is In Collected Data

Monitoring real life assemblies is the best proof of performance. This is how we know Pro Clima products make construction as safe as possible. ECOCOR monitored a foam-free, un-vented flat roof in Maine and clearly demonstrated how elevated assembly humidity in a super-insulated assembly can safely dry inwards through INTELLO Plus. As we describe in the presentation High […]

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April 17, 2017

Builder Testimonial: Brad Hankins on the INTELLO Energy Revolution

475 is excited to present this guest blog post by Brad Hankins, a designer-builder from Langley, WA. Long committed to sustainability, Brad knows the environmental benefits of high-performance construction. But Brad was also interested in understanding how quickly investments in energy efficient design pays for themselves, an important factor in convincing homeowners to jump on the high-performance bandwagon. […]

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April 17, 2017 Family exiled to trailer after home becomes unlivable.

Why Foam Fails. Reason #7: Unhealthy Off-Gassing & Dust

Spray foam throws off two forms of toxic poison:  off-gassing of the volatile organic compounds and uncured chemical dust. Spray foam is a two-component chemical system: Part A and Part B.  When the chemicals are properly prepared and precisely mixed, under the right site conditions, the chemicals will have a complete reaction eventually and become inert, ceasing to […]

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April 14, 2017 smartwall3d

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 and flaunted – they made up, down, and down, up – if they felt […]

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March 23, 2017 smartwallplan

Smart Wall Primer

The Smart Wall is an essential part of the Smart Enclosure and represents a return to fundamental principles of building science.  We leverage the basics of natural principles with highly selective technological innovation and manufacturing – working in harmony with nature, not in opposition.  The Smart Wall system is made of efficient, resilient and sustainable products, including HAVELOCK WOOL sheep’s […]

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March 14, 2017 MGI with INTELLO double stud fiberglass

New Mold Growth Index and Safe Double-Stud Walls: WUFI Pro Shows INTELLO Plus is Key

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 blog post The Double-Stud Wall Simplified: Low-Cost High Performance, and free CAD details)  Pack them right, meaning 3.8 to 4.2 lbs/cubic foot of cellulose, 2.5 lbs/cf for fiberglass or wood fiber – and as Jesse Thompson of Kaplan […]

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February 14, 2017 airtight gap

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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January 23, 2017 Vana_Moving

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 material (like superadobe), your building will consist of an array of different materials. In response to fluctuations in temperature and humidity, different materials expand and contract at […]

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November 22, 2016 crashtestdummy

Drive Safe, Build Safe

As we get ready to drive over the Thanksgiving and Christmas breaks, our minds turn to safety and the risks we take for granted every day.  What’s your risk tolerance? When you drive, do you tailgate the car in front of you or do you leave a safety buffer?  Although you are very unlikely to […]

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October 12, 2016 bainbridge-havelock-wool-thumb

Havelock Sheeps’ Wool and Performance Insulation

Insulation  contractors are on the front lines of high performance building, delivering comfort and efficiency.  It’s a tough business. It’s rough to manage high turnover, squeezed margins, and communication barriers.  Those who take pride in the work, are interested in the results.  And leaders do the best with what they have, while also continuously looking for […]

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October 3, 2016

New Yorkers, Start Your Blower Doors: It’s Blower Door Day

We’re happy to proclaim October 3rd Blower Door Day – here at our headquarters, in Brooklyn, New York – as the new residential building energy code requiring blower door testing at 3ACH50 comes into effect.  As we noted in May, of course New York isn’t the first to adopt the 2015 International Energy Conservation Code and keep […]

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September 9, 2016 ridge-vent

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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September 2, 2016 jeff_g_diagram

Cambridge MA – Small Urban 2-Story Gets a High Performance Upgrade

Here’s a sweet example of a successful Deep Energy Retrofit (DER) with airtight, foam-free walls and high performance ductless ventilation. The designer and GC is Jeff Geisinger, a Boston-based architect who recently completed a SMArchS in Building Technology at MIT. Peruse the stunning before-and-after photos along with Jeff’s great diagrams here (click on large photo for full-screen slide show). Airtightness Before Insulation With a recently […]

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August 16, 2016 swinburn_headline

The Dream Project: High Performance, Right-Sized, Thoughtfully Detailed

If you haven’t heard of Robert Swinburne Architect or Bluetime Collaborative yet, do yourself a favor and check out his website and blog. If you have followed his career, you know that he’s a talented and thoughtful architect focusing on single family homes in the Brattleboro, VT area. He is also a Certified Passive House Consultant (CPHC). One of Bob’s […]

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July 8, 2016 MelpetThumb

Healthy Indoor Air Quality Confirmed With LUNOS e²: Monitoring Shows HRV Does The Job At Melpet Farm

The residences at Melpet Farm is an affordable housing development by Preservation of Affordable Housing, Inc (POAH). Their mission is to create, preserve and sustain affordable and healthy housing communities that provide economic security and access to opportunity for all people. At Melpet, apartments were designed for low-energy use in townhouse buildings that incorporated airtight and highly insulated envelopes combined with hybrid LUNOS e² […]

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June 29, 2016 Large-back-wall

Blowerdoor Testing The Best Doggie Door In North America

We’re excited to put the super-efficient Freedom Pet Pass doggie door to the test. In this quick edit of the video, we introduce it by showing how the double-layer of magnetic strips work to hold the insulated flap in place while easily allowing for opening with the push of a big wet nose. These doors come in […]

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May 27, 2016 BlogThumb

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 has a big payoff as well. High performance windows deliver on interior comfort and building efficiency – so you don’t have to rely on energy-sucking HVAC systems […]

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May 23, 2016 double_stud

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 16, 2016 Blowerdoor_test

New York State Mandates Blowerdoor Testing Beginning October: Our Reaction

Airtightness is for Everyone As a company built on airtightness, we have always pushed the building industry and building codes toward progressively tighter and tighter building goals. Because even at “just” 3.0ACH50, increasing the airtightness of the building envelope will make a huge difference for the comfort and the energy efficiency of projects built to current code. […]

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May 5, 2016 EnergyLoss

Ventilation’s Energy Problem: Most Of It Just Sucks

Inaugural post of the Turning BS into Building Science series by Lucas Johnson Most often, ventilation sucks. When I was the third contractor enrolled in Energy Upgrade CA, I enjoyed being on the cutting edge of high performance building. However, ventilation was repeatedly one of the biggest challenges we faced as a state trying to push for affordable […]

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March 31, 2016 asphalt roof

The 8 Golden Rules for Foam-Free Unvented Asphalt Shingled Roofs

When insulating a wood roof structure, 475’s goal, as always, is to build in the most healthy, structurally sound and ecologically friendly way – thereby achieving truly high performance.  This means we generally try to avoid using foam above or below the roof deck (see our 475 series Foam Fails). With foam out of the equation, we […]

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January 8, 2016 explosion

Make Better Choices: Toward A Less Toxic World

Nature is toxic enough – it would seem sensible that we try to limit the amount of toxicity industry contributes.  Almost nothing is completely good.  But in the building industry as with much of modern life there are a dizzying array of invented chemical compounds that may provide great benefits but also deliver varying degrees of […]

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January 4, 2016 Screen Shot 2016-01-04 at 10.27.23 AM

5 Takeaways from the Building Science Corp Thermal Metric Study

The Building Science Corporation completed ground breaking research in 2015 – with an updated Thermal Metric Summary Report issued last June. Here’s our take on it: 1.  It’s an Amazingly Useful Tool In the executive summary BSC notes:  “Contemporary insulation materials and systems are more or less sensitive to thermal bridging, workmanship (i.e. quality of installation), internal convection […]

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