When retail cooperative REI set out to make a new line of apparel and outerwear essentials for the modern outdoors person, the first thing the company’s product developers did was closet dive. Yup, they sifted through people’s closets.

“We were looking in closets to learn what people use and what they don’t use,” says Nasahn Sheppard, divisional vice president of product design for REI. “It became obvious that no matter who you were or what your outdoor activities were, there were certain things that every single person had: a puffy jacket, a fleece and a quarter-zip. But nobody had ever created a line of these outdoor essentials. It just didn’t exist.”

So last fall, REI debuted the Co-Op line, a brand-new collection of pieces everyone needs if they’re spending time outside. This fall, the Co-Op line has undergone a major expansion, with the debut of new pieces, colors and sizing to enhance the collection.

“We have this philosophy we employ here at REI that we call ‘cooperatively designed,’” says Sheppard. “We learn from our core of almost 6 million members and almost 10,000 employees across the co-op. We learn from them, we go on the trail with them, we ask them what works and what doesn’t. We create product based on that.”

The REI Co-Op line features items everyone needs: a knit hat, made from a blend of acrylic and wool, a quarter-zip tech shirt, polyester-spandex capri-length tights for women, a down jacket and vest, and more. The fabrics are made with a deep commitment to sustainability and use only environmentally sound materials. Each product was created to utilize smart construction, streamlined design and performance-oriented fabrics.

“We focused on everything you need and nothing you don’t,” says Sheppard. “We really stripped the product down to the core function of what defines an outdoor product and we used premium materials delivered at a value.”

The new fall 2015 collection offers customers more choices than ever. The down jacket, for example, comes in eight different colors, and the fleece comes in nine. The down vest and jacket also now come in an extended size range, too.

The logo for the Co-Op line, which features mountains and a tree, was inspired by REI’s rich outdoor history and former CEO, Jim Whittaker, who in 1963 became the first American to summit Everest and who in 1978 led the first successful American summit of K2. A button on a climbing oversuit from the K2 expedition was the direct inspiration for the Co-Op logo.

Adds Sheppard, “This line is inspired by REI’s members but created for all.”