Gill said savings would amount to $15 million over the 30-year life of a bond to cover the additional expense.
"I want you to have the building you need the [pricing] mistakes were made by people before you but do we need everything on that list?" asked County Council Chairman David Wilde.
"I hope the final product is a building that is functional, but not lavish," added County Councilman Richard Snelgrove. "If it ends up a Taj Mahal, there will be hell to pay."
Despite their reservations about the extra $11.8 million, Wilde and Snelgrove were part of a unanimous council vote to forward the project to the county's Debt Review Committee. But they want the panel's recommendation of the lowest-cost bonding alternative to include a detailed look at the building's budget to ensure every expense is necessary.
Gill said he welcomed that analysis, noting his office and the mayor's had scoured the budget looking for savings. "We're not buying for the sake of buying," he said, but the office still will need furniture, more land for parking and other materials not included in the original budget.
The original $31 million plan included 109 parking spaces, insufficient for the office's 230 employees plus the needs of the public.
Even with additional costs, he added, the building will be worth it. Energy-efficiency measures incorporated into the design alone will save the county $118,000 a year.
Consolidating all of the district attorney's operations into one facility also will provide "intangible efficiencies" in the use of office supplies and equipment, technological support and staff interactions, added Deputy Mayor Nichole Dunn.
She accepted responsibility for the errors in the cost estimate for the building. But County Councilman Michael Jensen said she was just being valiant and that more of the blame should be affixed to Gill's predecessor, former District Attorney Lohra Miller.