The 2,545-square-foot Unit 1 has the added advantages of an entrance on each of its parlor, street and garden levels, a garden-level family room with wet bar and backyard patio, and distribution of the utilities in different closets to allow more storage on all levels.

Historic South End rowhouses tend to be either-or situations for homebuyers. If it’s a single-family, the space is there, but the upkeep onus is on the owner. If it’s a condo, the services are there, but you’re up against a wall if the family outgrows the unit or the in-laws need a place to crash.

Luckily, 36 Dwight St. offers a happy medium: a full-service condo with a townhouse feel. Renaissance Investments of the South End and Catamount Builders of South Boston have redeveloped this 1869 six-story bowfront as two three-bedroom, three-and-a-half-bath triplexes. Each boasts two gas fireplaces, a master suite with a balcony and more than 2,500 square feet of floor-through living space.

The 2,545-square-foot Unit 1 has the added advantages of an entrance on each of its parlor, street and garden levels, a garden-level family room with wet bar and backyard patio, and distribution of the utilities in different closets to allow more storage on all levels.

The parlor-level living-dining-kitchen space is another plus, particularly its art-gallery expanse offering front-to-back light and air, 10-foot-7-inch ceiling height, a herringbone red oak floor and generous wall area.

The bowfront expands the living space and offers a pristine street view of the old neighborhood. The floor-to-ceiling fireplace is tiled in white to blend with the crown and baseboard moldings.

The “white” theme continues in the open chef’s kitchen at the rear in the form of a faux marble Silestone waterfall island counter/bar, frosted cylinder pendant lights caged in hexagonal webs, paneled designer cabinetry and a backsplash tiled in a rare chevron pattern.

Contrasting the white are a light gray Silestone running counter and state-of-the-art stainless steel appliances, including a Wolf six-burner gas range with vented ceiling hood, a Sub-Zero fridge/freezer, a Marvel beverage center, and a deep sink with garbage disposal in the island. A glass slider opens to a balcony, extended on each side for intimate cocktails and overlooking neighbors’ yards for neighborly catch-up.

A powder room with old-fashioned floor tiles in scrolled trefoil and quatrefoil patterns is handily located by the stairs down to the street level. The stair land at the second street entrance from the door under the main stoop is approachable by stylishly tiled steps.

The second bedroom is elegantly shaped by the bowfront, and spear-head grills gracefully guard the windows in a way that complements the original scrolled cast-iron rails on the main stoop. The en suite bath features an onyx-tiled tub/shower with rain and hand-held shower heads, a quartz vanity and an over-mirror light with an ice-crystal texture.

The master bedroom down the hall features a double-door walk-in closet - ready for any kind of shelf configuration. A triple French window opens to a balcony rail overlooking the sunken backyard patio that is accessible from the garden-level family room (see below).

The master bath boasts radiant flooring and a deluxe glass shower, tiled in a designer pattern of varied grayscale stripes and offering multiple showering options: dual rain shower heads plus a hand-held head for showering separately, or a larger central rain shower for douching together. The twin-sink vanity has a textured marble counter, and three crackled-glass cylinder sconces are mounted on its mirror.

The garden level begins with a tiled laundry room and a cedar-lined closet for off-season clothing storage. The cozy third bedroom receives sunlight from a lightwell installed in the front garden. Its en suite bath has a glass shower tiled in a “sandy beach” theme, a marble-esque quartz vanity and a convenient pocket door to the hall.

The rear family room features a faux white marble gas fireplace flanked by artwork alcoves, a wet bar with a glass-brick backsplash and a wine cooler, a sizable closet and double French-door access to the sunken backyard patio for a full entertaining agenda or generous in-law accommodations.

The bluestone-tiled patio is surrounded by garden planters and a running granite ledge atop a concrete-block knee-wall, lit by low-voltage copper accent lighting that romantically brings out its rockface texture in the evening. Providing extra privacy is a solid wood fence, and the patio steps up to a gate to the back alley, for a separate entrance for the in-laws or an au pair.

Offered at $3.3 million, Unit 1 at 36 Dwight St. lets you grow your family or host your in-laws with townhouse pride of place.

For a private showing, contact Pam Holian at 617-650-1149 or Pam.Holian@GibsonSIR.com, or Brian Perry at 617-413-8049 or Brianp@GibsonSIR.com.

There will be an open house from 11 a.m. to noon on Saturday, May 11.

(Note: The artwork currently on display in the unit, ranging in style from abstract to animal-image to Warholesque, is for sale, as is the staged furniture. For details, contact Lanoue Gallery at 617-262-4400 [artwork] or Casa Design Group at 617-654-2974 [furniture].)