Bellwether Materials: A Startup in Sheep’s Clothing


Priscilla Burgess is presently one last fire-resistance test away from really putting the product that she’s developed over the past three years into motion. She’s already cleared the R-value and sound-resistance tests needed to certify that the building insulation her startup, Bellwether Materials, makes is ready for market.

Burgess, one of the 100 CleanTech Open semifinalists vying for the 18 regional finalist spots that will be awarded this fall, came upon her product idea—making insulation wholly from waste wool that is generated by the sheep ranching industry in the U.S.—by chance.

“I’d been talking to a sheep rancher, complaining about a potential partner [on another business venture] who had disappeared on me, and he said ‘You could always try using sheep wool for insulation,’” explains Burgess.

With that, Burgess started researching the market and found a couple encouraging facts. For one, she says, 90 percent of the sheep wool generated in the US is waste material—only 10 percent is fine enough to sell into the textile industry. As a result, much of that waste is landfilled or sold into foreign markets (she mentioned Mexico and China) at a break even price, if that. Another encouraging fact: while she found other companies making insulation from wool, none were doing it the way she wanted to and they were selling in foreign markets.

“These other companies have been looking to fiberglass insulation as a model and added plastic to the material,” she says. “We just went to the basic characterizes.” Second Nature UK sells an insulation called Thermafleece which contains some recycled polyester fibers, for example. And there are similar products made in wool-rich countries like Ireland and New Zealand. But these all use various types of plastic additives, says Burgess, which she avoids.

But while wool is naturally mold, pest and fire resistant, in order to boost those elements, Burgess adds boric acid to the wool. She packages the batting in used rice bags from a sake distiller, which makes it handy for inserting into walls and ceiling boards.

Burgess hopes to clear all the product testing hurdles soon so she can start selling her product. It has an R-value R-13 for 2×4 framing, R-19 for 2.6 framing and R-50 for ceilings. Cost-wise, it will fall between conventional fiberglass insulation and cotton batts.

Freelance writer Mary Catherine O'Connor finds that a growing number of companies are proving the ways that they can make good financially, socially and environmentally (as the triple bottom line theory suggests).With that in mind, she contributes to Triple Pundit, as well as to Earth2Tech and other pubs focused on sustainability. She also writes The Good Route, an Outside Magazine blog that addresses the intersection of sustainability and the active/outdoor life.To find out more, or to reach her, go to

2 responses

  1. What a wonderful idea! It’s ‘green’ and has so many applications. If used for upholstery there won’t be any residual gases leaking into the home. I wish I had thought of this! Darn

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