After standing vacant for more than a year, the downtown Westport landmark National Hall could be set for a new round of development.

The owners of the property, Greenfield Partners, a Norwalk-based commercial real estate firm, submitted last Thursday a preliminary proposal to the Planning and Zoning Commission that calls for zoning changes to allow for development of a new office facility at National Hall. The new plan will be reviewed at a P&Z meeting June 9 at Town Hall.

"I think this would really revitalize the area," said Greenfield Partners' land-use counsel, William Fitzpatrick. "We have the ability to fill that space with uses that my client thinks would be a significant benefit to the extended downtown."

The pre-application would precede a formal application by Greenfield for a text amendment to zoning regulations for the Historic Design District, where National Hall is located. Among a series of requested changes, Greenfield's preliminary plan asks the P&Z to eliminate a ban on office use on the ground floor of National Hall.

Greenfield's new proposal represents the latest chapter in a tumultuous recent history for the iconic property, which sits on the west bank of the Saugatuck River.

The P&Z approved in December 2009 an almost identical package of zoning changes proposed by Greenfield. At the time, Greenfield was a prospective buyer looking to acquire the approximately 20,000-square-foot property from then-owner, Antares Investment Partners.

A pair of west bank merchants subsequently appealed the decision to the Representative Town Meeting. In January 2010, the RTM upheld the petition, which ruled out Greenfield's plans for an office facility.

Two months later, the building's then-occupant, the Inn at National Hall, closed. The boutique hotel had operated at the site since 1993. In April 2010, a Greenfield affiliate acquired the mortgage on the property and ultimately foreclosed on it. Greenfield now owns the landmark. National Hall has a current appraised value of approximately $2 million, according to the Vision Appraisal website.

Greenfield Partners' pre-application also outlines redevelopment for several other west bank properties that it owns, such as the former site of the Peter Coppola Salon on Wilton Road. That space, currently vacant, could house a new restaurant.

A restaurant or retail establishment may also open in an annex next to the main National Hall building, Fitzpatrick added.

Built in 1870, the Italianate-style building housed a bank, a meeting hall and a furniture store prior to the inn's opening.