Ryann Newkirk, 3, chooses from a selection of books she has pulled from the shelves as she, her mother, Nealy Newkirk, and 8-month-old brother Nicholas visit the children’s room of the Lawrence Public Library on Tuesday. Library officials have requested that the city put a library expansion project on the November ballot. Among the areas included within the expansion and renovation plans are the children’s room, the computer area and public meeting rooms.

Deciding to support an expansion of the Lawrence Public Library in downtown was easy for a host of downtown merchants Wednesday morning.

Deciding whether they could live with the 2-mill property tax increase that likely would accompany the $18 million expansion will take more time.

“It is tough because those property taxes probably would get passed along to us in our rents,” said Rod Smith, owner of White Chocolate, 933 Mass. “But if the alternative is more sales tax, I know we can’t tax our customers to death. It is a real double-edged sword.”

The library expansion was the keynote topic at the semi-annual meeting of Downtown Lawrence Inc. Wednesday morning at the Eldridge Hotel. The merchants group plans to have more formal discussions about whether to endorse the project, if city commissioners agree to put a library bond issue on the November ballot.

“Higher property taxes often get passed along to the independent stores, and they probably are the least likely to be able to withstand those increases,” said Jane Pennington, director of Downtown Lawrence Inc. “But I know that that there is a very strong belief that an expanded library could be great for downtown.”

A few new details emerged on the library’s proposal. Library Director Bruce Flanders said the library board this week will interview architects to develop preliminary plans for the project. Flanders also said the library will deliver a report to the City Commission by June 1, with hopes the commission will make a decision this summer to place the expansion on the November ballot.

Flanders said it is possible the pricetag of the proposal may shrink. Current plans call for about $15 million to expand the library and about $3 million to upgrade parking.

“It seems a little high to me,” Flanders said. “The $18 million is definitely a not-to-exceed figure.”

As previously reported, Flanders said the expansion would focus on adding computer space, meeting space and children room space to the library at Seventh and Vermont streets, while also improving the energy efficiency of the entire 38-year-old building.

At $18 million, Flanders has estimated the project would require a 2-mill property tax increase. A mill is $1 in tax for every $1,000 worth of assessed valuation, or in other words, $11.50 per year in property taxes for every $100,000 worth of residential property a person owns.