Built in 1862-63 by John W. Rollins in the neighborhood's fashionable French Academic brownstone style, this 6,771-square-foot treasure was sensitively renovated in 2004 by Caruncho Martinez and Alvarez Architects of Miami to reflect today's tastes for smart-house convenience in the framework of 19th-century sensibilities.

Classic and convenient – who could ask for a better combo for contemporary living in historic Boston? Well, the twain meets seamlessly in the six-floor single-family townhouse at 208 Beacon St. in the Back Bay.

Built in 1862-63 by John W. Rollins in the neighborhood’s fashionable French Academic brownstone style, this 6,771-square-foot treasure was sensitively renovated in 2004 by Caruncho Martinez and Alvarez Architects of Miami to reflect today’s tastes for smart-house convenience in the framework of 19th-century sensibilities.

New-old features include an elevator hidden behind historically correct paneled doors, Victorianesque baths with electronic water and temperature controls, ceiling-concealed surround sound, closet-hidden multi-zoned HVAC systems including central air and hot-water tank, electrical rewiring to 400 amps/208 volts, and state-of-the-art appliances in a historical kitchen setting.

Capitalizing on the Victorian predilection for generosity of space and abundance of light, the renovation preserved the ceilings soaring as high as 14 feet, the tall windows and the floor-through layouts with end-to-end sunlight on all floors, and created a jewel box of a garden level with separate entrance and yard, a private roof deck, and a rear terrace over the two-car garage.

The foyer gives the first taste of this transitional design approach, catching light from the family room in back, making space for the breakfast room and kitchen, and leading up to the formal common areas with a rebuilt grand staircase of turned balusters ending in pendant drops side-attached to the steps.

The breakfast room’s marquetry floor of shadowed hexagons and carved maple fireplace with green hearth tiles add elegance to morning coffee.

The chef’s kitchen is configured with parallel soapstone running counters, ceiling-high paneled cabinetry encompassing all appliances, and floor-through light between the breakfast and family rooms. Beige backsplashes of glass-granule tiles enrich the Viking six-burner gas cooktop and the stainless sink with copper gooseneck faucet.

The family room blends historical details with contemporary flexibility. A carved arched fireplace with an over-mantel mirror faces an open wall for bookcases or an expansive entertainment center. A leafy plaster molding dangles a period-style chandelier of six marbleized glass bowls.

The “piano nobile” level upstairs showcases Victoriana in grand form with a formal dining room offering picturesque neighborhood views and a formal living room with a “Back Bay” river view bay window. The dining room lets you entertain in elegance with its carved arched Carrara marble fireplace, leaf-scrolled plaster ceiling medallion and triple crown molding.

The baluster-railed French balcony is consistent with this townhouse grouping on Beacon Street. The mustard walls, cream trim and gold fixtures are dazzling with the crystal chandelier and eloquent dining room arrangement.

The gray-walled living room with triple crown molding and marble fireplace carved with rosettes features a domed ceiling and a robust bay window with eyebrow casing and window seats to enjoy dramatic river views.

This floor-through level initiates a straight-up skylight that brings sunlight to all bedroom levels through frosted casement windows in the master-suite closet corridor and the upper level baths.

An elegant powder room with terra cotta brick-tile wainscoting introduces the curving staircase to the third-floor master suite. It reprises the floor-through format, connecting the rear bedroom to the front bath with a hall of built-in closets, shelves and drawers for dressing convenience.

The master bedroom suite has an arched marble fireplace with a cast-iron grill enclosure in a mandala design and two windows affording sunset views of the Charles.

The sophisticated master bath features Victorian-style plumbing and tilework: a mosaic marble floor, Carrara marble wainscot tiling in Paris-Métro fashion, freestanding marble vanities, a marble-wainscoted commode alcove, an oblong soaking tub with hand-held showerhead, a marble-tiled shower with rain showerhead, and a chrome towel-drying rack.

Connected to the master bath is a dark blue sitting room with an arched marble fireplace.

The floor above the master suite level affords the luxury of flexible space. Each pair of rooms can be interconnected by opening up the wide double door that separates them and closed off from one another as desired. One room in each pair has a black marble fireplace. These spaces can be used as family bedrooms, private studies or guest quarters.

The twin central baths have basket weave-patterned marble floors and Paris-Métro tile wainscoting; one has a standup shower and marble-countered wall sink, the other a tub/shower and pedestal sink.

The mansard roof encloses a guest suite. The well-closeted front bedroom has pristine rooftop views, and the rear study has ample workstation space and stunning river views. The floor-through hall accesses a wood-floored bath with iron clawfoot tub and a deluxe laundry room with spacious sorting and folding counters.

The penthouse roof deck embraces both Boston and Cambridge with its panoramic views of the Financial District, the Hancock and Prudential towers, the historic beauty of the Back Bay and the shimmering waters of the Charles - all a perfect backdrop for summer cocktails and company.

The garden level, separately entered from the street via the curlicue-paved front garden, could be an au pair, in-law or staff suite. It comes complete with elevator-accessible hall, cozy bedroom, full bath, kitchenette, powder room and a roomy living/gym/media/play space accessing the rear garden through a double French door.

Modeled on the “hidden gardens” of Beacon Hill, the garden has a recreation-ready grass plot, a brick wall with trellises for climbing plants or grapes, a new classic colonnade along a Beacon Hill-style brick walkway toward the garage and a spiral staircase up to the over-garage terrace.

Offered at $14.9 million, 208 Beacon St. puts history and high-tech on equal footing with its uniquely “retro” retrofit.

For a private showing, contact Kevin Ahearn at 617-922-8744 or Kevin.Ahearn@elliman.com; Lisa Rainis of Douglas Elliman Real Estate at 617-877-8852 or Lisa.Rainis@elliman.com and Michael L. Carucci of Gibson Sotheby’s International Realty at 617-901-7600 or Michael.Carucci@gibsonsir.com.