One Dalton rises at the juncture of two Boston neighborhoods: the Back Bay, with its tree-lined streets of nineteenth-century townhouses, and the western end of the city’s High Spine, comprising the largest-scale complex in Boston, with the 52-story Prudential Center at its heart.

This fascinating juxtaposition of scales presented one of the major challenges of the project.

A second challenge—the site’s unusual equilateral triangular shape—is a product of the nineteenth-century railway lines and former railyards, which dictated the street plan, and Massachusetts Avenue, which edges the array of Back Bay blocks. To mitigate the aggressively long sides and sharp corners of the triangular site, the plan of the tower has been shaped as a soft triangle, with three curved sides and smaller-radiused curves at the corners.

The exterior wall of the residential portion of the tower is shaped by incisions on the surface, offering views in two directions from every room and allowing for operable sashes—a rarity in tall buildings. The incisions give the building a distinctive personality both inside and out, while distinguishing the tower’s two different uses: 174 residential condominiums on the top forty floors above, and a 215-room hotel on the 20 floors below.

The glass between the incisions extends beyond the right angle that forms the operable sash, protecting the sash from precipitation and Boston’s high winds. The glass on the surface of the tower is gray-tinted, offering very low reflectivity as well as low UV and solar-radiation transmittance.

Reaching out to the three corners of the triangular site and rising to the height of the nearby townhouses, the podium makes the 61-story tower a good neighbor. With expanses of warm gray granite, punctuated by clear glass shaded by wood louvers, the building presents an open and welcoming demeanor at ground level. Despite their distinct character and materiality, tower and podium are intimately engaged: sections of the tower’s curtain wall descend through the podium. On one face, this break in the podium frames the hotel entry.

A small triangular park opposite the hotel entry, where St. Germain Street meets the tower, serves as a mediating space that further integrates the building with the surrounding neighborhood.

One Dalton demonstrates how a tall building, together with the open spaces it frames, can respond creatively to the need for growth while showing appropriate respect for a historic urban setting.

CLIENT: Carpenter & Company, Inc.

PCF&P SERVICES: Competition and concept design in collaboration with Cambridge Seven Associates, architecture; exterior envelope

SUSTAINABILITY: Designed & registered for LEED Gold

AWARDS

Global Winner, Best Tall Building (200m-299m) Council on Tall Buildings and Urban Habitat, 2022

American Architecture Award Chicago Athenaeum, 2020

Design Award of Honor Society of American Registered Architects, 2019

Architectural Design / Tall Buildings Architecture MasterPrize, 2020

The Architecture Community: Global Design Award, Hospitality Projects World Design Awards, 2020

Rethinking the Future Award: Large-scale residential RTF Architecture Awards, 2020

Winner, Architectural Design: City Destination LIV Hospitality Design Awards, 2021

Winner, Architectural Design: Luxury Hotel LIV Hospitality Design Awards, 2021

Gold Key Awards: Best Luxury Guestroom Boutique Design, 2020

Best in Boston Real Estate: Residential Boston Business Journal, 2015