Updated at 10 a.m. with information from e-mail exchanges between WCC and the contractor.

Washtenaw Community College President Larry Whitworth says problems with a contractor have thrown a wrench in the school’s plans to begin an environmentally-conscious overhaul of a key skilled trades building.

The WCC Board of Trustees halted negotiations with Spence Brothers on Tuesday, yanking an $11.4 million contract for a renovation of its occupational education building and handing it over to O’Neal Construction for $11.45 million.

Whitworth said Tuesday the project stalled after the firm switched subcontractors on an important piece of the renovation, then asked for more money to return to the original list.

Whitworth said subcontractor problems have surfaced in the past. A few years ago, a subcontractor hired for mechanical work went bankrupt during a renovation of the Crane Liberal Arts and Sciences building, which delayed the work, sparked lawsuits and cost the school much more than it had anticipated, he said.

Whitworth said O’Neal was the second runner-up in the school’s bidding process, which considers factors other than cost, including the financial viability of subcontractors.

But an e-mail exchange between a WCC administrator and Spence Brothers shows WCC may also have objected to Spence Brothers using a non-union contractor for 200 planned geothermal wells.

In that e-mail exchange obtained by AnnArbor.com, the firm defended itself by saying it had not received any union bids for that portion of the project.

While Spence is a union contractor, “There is no requirement in the bid documents that any contractor be union,” executive Bob Spence wrote.

Whitworth called the union issue “totally irrelevant.”

“What they didn’t want to deal with was the fact they were swapping out their subcontractors,” he said.

Work on the college’s occupational education building, a 30-year-old facility used to teach welding and auto repair, was expected to begin immediately after the WCC Board of Trustees approved the Spence Brothers contract on July 27. The Michigan-based firm has regional offices in Ann Arbor.

The college had had already vetted the agreed-upon subcontractor, John E. Green, to do the mechanical work, which makes up about 80 percent of the renovation project, Whitworth said. The Detroit-based firm has an Ann Arbor office.

According to Whitworth, Spence Brothers representatives substituted John E. Green with another firm. When the college protested, Spence Brothers asked WCC pay an additional $200,000 to return to its original plan, Whitworth said.

In an e-mail responding to questions from WCC, Spence Brothers defended the substitution.

“Subsequently, when the college selected alternates, it was determined that Green was not the low mechanical bidder, and thus was not submitted as the post-bid mechanical contractor,” Spence wrote.

AnnArbor.com could not reach Spence Brothers representatives by phone.

The contested renovation is part of a $14.8 million; state-funded makeover of two skilled trades buildings on campus. The bulk of the work involves WCC’s 120,000-square foot occupational education building. It’s due to receive hundreds of geothermal wells; a new, energy-efficient roof; as well as mechanical upgrades to the electrical and heating and cooling systems.

A vacant skilled trades annex will also get a new look. The board approved Ann Arbor-based Hobbs + Black as the architects for that job on July 27. Plans include re-designing the 7,500-square-foot space into a classroom for the college’s construction program, where students will have the space to learn to build houses hands-on. That program is currently housed in leased space in Ypsilanti Township.

Juliana Keeping is a higher education reporter for AnnArbor.com. Reach her at julianakeeping@annarbor.com or 734-623-2528. Follow Juliana Keeping on Twitter