Despite budgeting problems, the expanded Chapel Hill Public Library will be the first town building slated to receive a sustainability certification from the U.S. Green Building Council.

Because the construction company could not guarantee a price below the $12.5 million budgeted for the expansion after receiving bids from subcontractors, town officials are changing some aspects of the library’s design to reduce construction costs.

“All of the proposed modifications have been reviewed and approved by Robert A. M. Stern and Associates, the lead architect, for consistency with their intended design concept, and with library staff to assure that the functionality of the project is not compromised,” said Town Manger Roger Stancil in an email to town council members.

“The proposed modifications retain the project’s eligibility for LEED silver certification and do not include changes to the size of the building,” he said.

All new public buildings in Chapel Hill are required by a 2004 town ordinance to achieve a Leadership in Energy and Environmental Design (LEED) silver rating by the U.S. Green Building Council.

LEED ratings come in four levels: certified, silver, gold and platinum.

The Chapel Hill Public Library will be the first building to fall under the ordinance, Town Sustainability Officer John Richardson said.

No green features will be cut from the library despite budgeting problems, said Curtis Brooks, urban forester for the town, even though not all of them are required for LEED certification and many involve large upfront costs.

It wouldn’t make sense, he said, considering all the money that had been spent in the planning phase to design the green features.

“Half the cost has already been paid,” Brooks said.

Planned features include a high-efficiency heating, ventilation and air conditioning system, a path to a nearby bus stop, rooftop solar panels, covered bicycle storage, expansive windows, natural lighting and electric vehicle charging stations.

Instead of shedding these features, the town is working to give developers a variety of choices in material use and specifying less expensive aesthetics to lower construction costs.

While some of the environmentally friendly library features are expensive, Richardson said that incorporating green building practices at the beginning of the design process can save money long-term.

“Although LEED certified projects were initially reported as being costly to build, more recent findings suggest that these projects can be cost-competitive,” Richardson said. “Green building proponents often times flip the question around to ask, ‘What are the costs of not doing green building?'”

These costs include higher electricity bills, Brooks said.

The heating, ventilation and air conditioning system that will be installed could account for as much as 10 percent of the upfront building cost, Brooks said.

“The high-efficiency HVAC system will, by its nature, cost more,” Brooks said. “But that system will generate savings in the long run.”

Not all features will significantly help with LEED certification or energy savings – like having large windows – but they will improve the library user experience, Brooks said.

Despite the bidding setback, town officials hope the library will be completed January 2013.

New bids are due Nov. 3 and changes will not be finalized until the town council reviews them at the Nov. 21 town council meeting.