A proposed change to the town's zoning regulations, which would allow second-floor retail use on Main Street and Post Road East in the town center, is getting a mixed response from Planning and Zoning Commission members.

Text Amendment 654, submitted by architect Bill Achilles on behalf of the owners of 7-17 Main St., would permit retail establishments to operate above the first floor in the Business Center District, which encompasses much of downtown Westport. It would allow up to 13,000 square feet for a two-story retail establishment and 3,300 square feet for a retail outlet based solely on a second floor.

Offices, apartments, restaurants and retail food establishments are already allowed to operate above the first floor in the Business Center District, according to current town zoning rules.

Achilles, along with planning consultant Mel Barr, say the proposal could boost prospects of downtown property owners and foster more retail diversity in the town center.

"Our client happens to be one of the persons who's struggling to find new tenants in today's economy and he's interested in a second-floor option," Barr said at Thursday's P&Z hearing on the proposal. "This amendment would help encourage more locally owned retail uses of a broader variety in smaller, less expensive second-floor space."

The 7-17 Main St. property, straddling the corner of Main Street and Post Road East, includes the women's clothing store LOFT on its first floor, as well as several apartments. LOFT would like to expand to the second floor, a desire partly motivated by flooding damage it sustained during Superstorm Sandy, Achilles told the Westport News last week.

If approved, 13 properties in the Business Center District -- five on Main Street, seven on Post Road East and one on Bay Street -- would be affected by the amendment, according to Achilles and Barr. The combined second-floor footprint of those 13 properties totals approximately 77,000 square feet. Enactment of the amendment and the subsequent conversion of all that square footage to retail use could lead to increased parking demands and more traffic, according to a report by Deputy P&Z Director Mary Young.

Additional parking would not be required for the conversion of any second-floor space into retail spots, provided that no new floor area were added.

Achilles and Barr told the P&Z the creation of new second-floor retail use would probably occur in smaller buildings on Main Street, due to the thoroughfare's existing retail variety, high customer foot traffic and proximity to municipal parking. The four largest buildings in the Business Center District are not currently permitted to have upper-floor retail use would be less likely to be affected by the amendment, they said. Excluding those four sites, the amount of second-floor space that would be available for new retailing operations would total about 30,000 square feet.

Text Amendment 654 is more restrictive in its conditions than a text amendment proposed in 2004, which sought the approval of upper-floor retail use in the downtown's Business Center District/Historic zone. The 2004 amendment was rejected by the P&Z.

Second-floor retail operations already exist in the Business Center District, due to zoning waivers known as "variances" and longstanding non-conforming uses permitted by town zoning officials. One of the town center's cornerstone retail buildings, 125 Main St., uses three floors for Gap and Brooks Brothers Women outlets.

P&Z Secretary Chip Stephens was the commission's most vocal skeptic of the amendment during the Thursday hearing.

"My initial look at this was the 77,000 square feet and that, to me, is scary in terms of extra usage," he said. "I don't want to be the man of negativity all the time, but I am going to focus on parking and I am going to talk on congestion and it's just a little bit irksome where everybody minimizes it to the point where it doesn't make any difference."

Howard Lathrop, meanwhile, expressed doubts about the potential economic benefits of the amendment.

"Most of the buildings, first and second floor, are occupied anyway," he said. "If you were coming in here and saying 25 percent of the buildings are empty, what do we do, that's one thing. But you're coming in and saying they're all rented. What's the advantage? What are we gaining?"

In contrast, commissioners Ron Corwin and Nora Jinishian indicated interest in the proposal if it could attract more independent businesses to the town center.

"This strikes me as just the kind of thing we ought to do," Corwin said. "It creates opportunities for people who can't afford the first floor, it allows for smaller units of real specialty and interesting places. This is a direction that I think the commission would be well-served to consider."

Gloria Gouveia, a Westport-based land-use consultant, was the only member of the public to comment on the amendment at Thursday's meeting. She expressed support for the amendment, noting that upper-level retail use in the Business Center District was prevalent in the 1960s and 1970s when major Main Street stores such as Sloane's Furniture and Klein's of Westport took up several floors.

"The [proposed] regulation is consistent with the natural ebb and flow of the use and development of Main Street for the past 50 years," she said.

pschott@bcnnew.com; 203-255-4561, ext. 118; twitter.com/paulschott