To be called Beacon on the Park, the development will comprise of just two extraordinary homes - a tri-level penthouse and a parlor-level duplex. In addition, these condominiums will have off-street parking.

A distinctive Victorian bow front townhouse at 89 Beacon St. overlooking the Public Garden is undergoing a complete gut rehabilitation/restoration to create the ultimate in exquisite living.

To be called Beacon on the Park, the development will comprise of just two extraordinary homes – a tri-level penthouse and a parlor-level duplex. In addition, these condominiums will have off-street parking.

The developer, 89 Beacon LLC, is a collaboration of Jeffrey Leerink of Leerink Development LLC and Jeff Novack of Novack Properties; the architect of record is Ronald Payne of Payne | Collins Design, and the general contractor is Jackson General Carpentry. Their signature projects are scattered throughout the Back Bay and Beacon Hill.

Celebrity designer Michael Carter created the interior layouts.

The exclusive broker is Shelagh Brennan of Cabot and Company who is listing the four-bedroom penthouse with three full baths and three powder rooms at $15,995,000.

The three-bedroom duplex, which will have three-and-a-half baths, is listed at $4,195,000. The homes will be delivered next summer.

“I’ve had a penchant for old buildings, and Jeff, who grew up just a few doors away, brought this building to my attention,” said Leerink, who developed the Clark-Weld House at 304 Commonwealth Ave., Riverside Beacon at 196 Beacon St. and, most recently, the Whitwell, a 14-unit condo conversion on Derne Street, Beacon Hill.

“Beacon on the Park is going to be phenomenal. It will have exceptionally high ceilings, high-end finishes, all new systems, all the little extras, the thoughtful details, you would find in a fine hotel.”

The townhouse at 89 Beacon is one of four row houses built circa 1852 by Fox, Standish and Turner, according to Bainbridge Bunting’s “Houses of Back Bay, an Architectural History 1840 to 1917.” Number 89 is paired with its easterly neighbor, and part of the exterior restoration will include matching the oversized windows to the adjacent building at 88 Beacon and extending cast iron fencing in front of the townhome.

Inside the double door entry with a transom will be a white Carrara marble-tiled vestibule, incorporating the original fleur de lis design. A second set of double doors will open into a marble-tiled lobby.

To the left will be the entrance to Unit 1, and straight ahead will be the penthouse entry with a private elevator. Next to it will be a grand, open curved staircase that will ascend to the floors above.

On the first level of the penthouse, which will have five-inch-wide quartered, rift-finished white oak flooring, laid in a herringbone pattern, the stairs will open to an expansive kitchen, anchored by an island. With breakfast seating for four, the Carrara marble-topped island will have waterfall ends and will hold a Miele dishwasher and drawers.

The custom-designed cabinetry with polished nickel knobs will be from the Refectory series of individually handcrafted pieces by internationally renowned designer Christopher Peacock.

Top-of-the-line appliances will include a 36-inch-wide Sub-Zero refrigerator and a separate 36-inch-wide Sub-Zero freezer, plus a 48-inch-wide Wolf dual-fuel six-burner gas range/oven with a griddle. Above it will be a bespoke custom hammered nickel hood.

Close by the elevator will be a Sub-Zero wine cooler. And another wine cooler and a smaller refrigerator will stand side by side in a nearby pantry with a swinging door. Opposite will be a small deck.

A hallway will continue to a spacious dining room or a library, which will have access to a larger deck that overlooks Beaver Place. This mahogany-paneled room will have a wide gas fireplace with a glass front and a Chesney “Monroe” mantel. Custom-built shelving will flank the fireplace. For convenience, a powder room will lie between this main room and the pantry.

On the other side of the kitchen will be the grand, sun-filled living room with a gracious gas fireplace with a Chesney mantel, flanked by built-ins. The ceiling, to be rimmed with triple crown molding, will soar more than 12 feet.

Directly above the living room will be the master bedroom suite, which also will have a fireplace. A large walk-in closet/dressing room with access from either side of the bed wall, facing the fireplace, will be furnished with shelving and double hanging rods. A beverage center will be tucked into a corner. A second-walk-in closet will offer more storage and will lead into a lavish master bath with radiant heat.

A stand-alone soaking tub by Victoria + Albert will stand opposite a long double vanity with undermount sinks, next to which will be a linen closet and a toilet. There will be a spacious glass-enclosed shower with a bench as well, tiled with honed Calacatta stone. The flooring in the bath will be polished Calacatta.

At the other end of this level, beyond a large laundry, will be a second bedroom suite with a good-sized walk-in closet and an en suite bath with a single vanity and a soaking tub. The laundry will include a side-by-side Electrolux washer and dryer and a sink.

The top floor will feature two bedrooms with large closets. The larger bedroom will have an en suite bath with a shower and a single vanity that can also be accessed from the hall, which will include a powder room.

A spacious family room with two skylights, a fireplace and a wet bar will occupy the remaining floor space on this level, which will have French doors that will open out to a huge roof terrace. In addition to phenomenal views, this deck of limestone will be furnished with an outdoor kitchen and a six-person hot tub paneled with ipe Brazilian wood.

Within the family room will be a mezzanine to take advantage of the sloped roof. A spiral staircase will lead up to this area, which could be used as a study or a home gym. It will have a powder room too.

The duplex will boast many of the same high-quality sophisticated amenities as the penthouse. From the lobby, the entry will open into a magnificent living room with a fireplace and a soaring ceiling with crown molding.

Bow windows will look out to a landscaped garden and to the well-known Robert White Memorial, depicting an angel, designed by Daniel Chester French.

The living room will have an English Regency marble fireplace mantel and a honed absolute black granite hearth. The room will flow into a state-of-the-art kitchen, which will feature a wall of high-end appliances – a Sub-Zero refrigerator and a six-burner Wolf gas range with a convection oven and a custom, hammered nickel hood – facing a 10-foot-long center island.

More cabinetry will line the wall of a dining area, which will look out to a small deck.

A passageway with a cove ceiling will lead to the master bedroom and en suite bath, which will have a stand-alone elliptical soaking tub, a marble-topped double vanity and a separate glass-enclosed tiled shower.

Between the master suite and the dining area will be a copper-clad bay or oriel that will be built out as a powder room.

A set of stairs opposite the kitchen island will descend to two additional en suite bedrooms with generous closets. One of the baths will have a soaking tub; the other will have a shower. Beneath the front steps of the townhouse will be a private entrance to the garden level of the duplex, and at the far end of this home will be access to a private landscaped courtyard and to two outdoor parking spaces behind a motorized iron gate.

The penthouse also will have two outdoor spaces as well as a garage space, which will lead into its big mudroom, stairs and elevator.

When completed, these two incredible homes will epitomize modern-day elegance and sophistication in an unparalleled location facing the Public Garden.