Southeast Michigan goes from cold and dry winters to hot and humid summers. Those kinds of extremes demand insulation that can live up to the task. But we also believe good home design and construction shouldn’t be separated from thoughtful stewardship of our planet. We consciously select the materials we use to reduce a home’s carbon footprint, whenever possible.

That commitment to high performance and responsible stewardship led us to a remarkable company called Havelock Wool. Natural wool insulation improves indoor air quality, manages moisture, and neutralizes volatile organic compounds. We’re beginning to use wool insulation in our sustainable home construction projects, and our customers are excited to have it as an option.

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Meet Havelock Wool

Havelock Wool started on a very simple premise about six years ago: that there was an exceptional, natural, high-performance fiber out there that was designed to be an insulator. Wool is an amazing product, which is not only natural but healthy and high-performing.

It took some time for the company to gain traction, but Havelock is now getting flooded with calls from homeowners and builders.

Why Wool Insulation?

Havelock wool installed

A coarse wool fiber is one of the most dynamic fibers on the planet, making it a nearly ideal insulator. It’s effective in climates that are wet, dry, hot, and cold. If you look at wool under a microscope, you’ll see that wool has five follicles, which gives it remarkable integrity.

“What wool does very well, first and foremost, is last over time as an insulator,” founder and managing partner Andew Legge said. “So you’re getting an r value, which is the measure of thermal conductivity — that’s how we look at insulation — you’re getting one that’s as good or better than other forms of insulation.”

Andrew said that there are several inherent qualities in the fiber construct that make wool an ideal insulator. Let’s take a look at some of these characteristics.

Moisture management

Wool absorbs and desorbs against 65 percent relative humidity. When the relative humidity is over 65 percent, wool absorbs that moisture and holds on to it. When the humidity drops below 65 percent, it releases that captured moisture.

“The beauty of that is wool is also a keratin, so it’s not going to support the growth of mold,” Andrew said. As home construction companies build more air-tight structures, moisture gets trapped in the cavity. “You need a medium in there that can manage it and not be destroyed, not harbor mold growth. Wool is the only thing available that can do that long term.”

Toxin filtration

Homeowners today are more conscientious than ever about the toxins that are common in homes. Wool insulation provides some passive filtration of toxic chemicals that can escape traditional construction materials and home environments. The amino acids in wool will irreversibly bond with formaldehyde, nitrogen oxides, and sulfur dioxide.

Related reading: How Does the Design of Your Home Affect Your Wellbeing?

Sound absorption

A home becomes a refreshing retreat when you can enjoy a quiet evening at the end of the day. You don’t want the intrusion of traffic noise and ambient dissonance from outside.

The acoustic buffering characteristics of wool are hard to match. While there are products available that are designed specifically to attenuate sound, Andrew said that no other standard insulation does a better job of absorbing sound than wool.

Environmentally friendly

Wool insulation is a 100-percent all-natural product. “At the end of its useful life, you’ve got a fiber that can be composted,” Andrew said. “That’s of increasing interest to people.”

Fire protection

One concern many people have when choosing insulation is flame resistance. Because wool has a high nitrogen content of around 14 percent, it’s naturally self-extinguishing.

“Those are all the reasons why we started this company,” Andrew said. “While there’s no silver bullet to insulation, wool is about as close as you’re going to get.

“It’s the fiber that nature has given us.”

What Are Homeowners Saying?

Havelock wool insulation in a ceiling

As innovative as wool insulation may be, the proof of its promise is in daily living — season to season and year to year.

“The people who use us, they love wool insulation,” Andrew said. “We’ll have somebody who insulated with our stuff and they’ll call us back a year later and say, ‘I can’t believe how great the space feels. I can’t believe the temperature control because of the moisture management. I can’t believe the sound attenuation.’ That makes us feel great.”


Working with Giraffe

Andrew said that having a supporter like Giraffe feels great, too. “I’m personally thrilled that there are groups out there that take an interest in how to build properly.

“I would recommend that people find a group like Giraffe that gets it and is passionate about doing things properly, because it’s hard to know how to do this stuff. It’s hard to find how to do this properly. It amazes us how many architects don’t know a lot about these issues.”

At Giraffe Design-Build, we believe good design is sustainable design. If you’re looking for a home that marries good design, excellent craftsmanship, and sustainable practices, we can provide inspired solutions you’ll be delighted with, for years to come.

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