BOULDER - Koelbel Urban Homes, home-building affiliate of Denver-based Koelbel and Company, has purchased 6.12 acres of land in North Boulder for $3 million where it plans to build 31 single-family homes, with three qualify as affordable housing.

TrailCrossing at Lee Hill is bounded by Lee Hill Drive, Yellow Pine Avenue, Eighth Street and 10th Street, and is the former site of Boulder County's fire-training center.

Allison Management LLC had been planning to partner with Boulder nonprofit Thistle Communities to build the neighborhood they were calling 820 Lee Hill. Allison Management and Thistle purchased the land from Boulder County last year for $3 million.

Koelbel, as KUH Lee Hill LLC, purchased the property from 820 Lee Hill Road LLC - Allison Management and Thistle - in June, according to public records.

Koelbel and Company spokesman Mark Samuelson, said Koelbel is taking over the project, and will be similar to what the previous owners of the land envisioned.

The project is subject to final review by the city of Boulder. Koelbel hopes to start pre-selling homes this summer and start construction this fall.

The homes will range in size from 1,280 square feet to 2,300 square feet.

"This is a particularly important project for Koelbel and Company, said Carl Koelbel, project manager at Koelbel Urban Homes. "Our 60-plus years of residential building and land development in Colorado has often focused on Boulder and its residential and commercial sites. ...  The challenge of providing affordably priced homes within the parameters of Boulder area land costs is something uniquely suited to us."

Koelbel's presence in Boulder includes a long involvement with the University of Colorado and its Leeds School of Business. The business school's 160,000-square-foot building is named after the family in honor of the Koelbels' $4 million gift that went toward its construction.

Prices for TrailCrossing's single-family homes are expected to range from $470,000 to more than $700,000, said Dana Keller, Koelbel's vice president of sales and marketing. The remainder of the homes will include one- or two-car garages, master suites with walk-in closets, and options for an energy-efficient gas fireplace; and all homes will provide wide-open family-dining-entertaining areas and island kitchens, Keller said.

One Koelbel plan will offer a main-floor master suite, and several will have rooftop decks.

Three of the homes will be in compliance with Boulder's affordable homes program, at prices starting at the mid-$300,000s, for buyers who qualify for the program and abide by some resale restrictions.

The project will include a community park and garden with adjacent picnic shelter. All homes will be close to the route of Boulder's Fourmile Canyon Creek Trail connecting into the foothills as well as to Boulder's main trail system leading to office campuses along Foothills Parkway, South Boulder Creek and Dry Creek.

Koelbel Urban Homes previous projects in new-urban settings in Denver, including in Lower Highlands, Platt Park, and downtown Denver's Ballpark district.