LEWISTON — The Planning Board will hold public hearings Monday on two separate rezoning proposals in the downtown area, as well as new design guidelines for downtown development that were created over the past year.

The zone changes are meant to encourage development of vacant or underutilized sites, while the design standards were formed to produce development that better fits the character of the downtown.

The first proposal looks to rezone properties along Pine Street and Leeds Street from the Community Business district to the Downtown Residential district, as well as areas in the Tree Streets neighborhood zoned Neighborhood Conservation “B” to Downtown Residential.

City Planner Doug Greene said the measures would create a more “unified” downtown residential zone in the Tree Streets area, intended to encourage development of vacant or underutilized spaces and redevelopment downtown.

The Planning Board will also discuss a proposal Monday to rezone a large swath of downtown properties that do not conform with their current district. If approved, a rezoning would shift 56 parcels from the Downtown Residential zone to Centreville, which is the city’s most urban district with no density limits. Most of the parcels are on Blake, Oak and College streets.

The proposal was spurred by a development plan from Lewiston Housing, which is looking to expand on the Ash Street side of its Blake Street Towers housing complex at 70 Blake St.

Officials there are looking to build a three-story, 40-unit apartment building using vacant land on the property that they say is underutilized parking. When looking at the proposal, city staff saw multiple parcels between the site and the Centreville boundary that they believe could be more suitable for redevelopment under the Centreville standards.

The board will make a recommendation to the City Council regarding the Design Lewiston site plan review and design guidelines, which were developed with the help of a committee over the past 18 months.

If ultimately approved, new projects in the downtown district would be required to follow a series of exterior building standards for entrances and windows, parking access and design, landscaping and an overall design that shows “compatibility and harmony with surrounding buildings.”

While some officials, including Mayor Mark Cayer, were reluctant to support the new standards due to the potential for added development costs, it now has broad support.

During a recent council discussion, David Hediger, director of Planning and Code Enforcement, said most developers want a clear understanding of the requirements, rather than getting last-minute costs added to projects. He said the design standards and updated code elements will help with that.

When asked if the standards would allow the city to dictate design elements to a big-box store, Greene said the standards are meant for the downtown district only in order to not be overly restrictive citywide. If the elements end up being popular, he said, “they could perhaps be expanded.”