It is an advocate of the plant kingdom. When people discuss the magnificence of the New York Botanical Garden (NYBG), the sentiment is one of the first things that comes to mind. Established in 1891, the iconic NYBG is distinguished by the beauty of its landscape, collections and gardens. The scope of its excellence extends into the myriad programs in horticulture, education and science.
NYBG was inspired by an 1888 visit that eminent botanists Nathaniel Lord Britton and his wife, Elizabeth, who took to the Royal Botanic Gardens, Kew, near London. The Britton’s believed New York should have a great botanical garden to advance public understanding of plants, so the concept of the park was born. The 250-acre garden sits on picturesque terrain on the northern half of Bronx Park, defined by the freshwater Bronx River, rock-cut gorge and 50 acres of old-growth forest.
During the 129 years since its founding, NYBG carefully has stewarded a stunning urban oasis, along the way creating one of the world’s most comprehensive plant research and conservation programs, unrivaled research collections and a living museum.
Recently NYBG finished an epic restoration, spearheaded by the EW Howell Construction Group. The $18 million renovation of the iconic Palm Dome of its Enid A. Haupt Conservatory began in April 2019. The 118-year-old dome is home of the Haupt Conservatory’s celebrated Palms of the World Gallery.
The project also provided an opportunity for NYBG horticulture curators to redesign and replant the collection to highlight the history of tropical plant research at NYBG and the ecological and economic importance of the Palm family.
Restoration with respect
Constructed by Lord & Burnham Company and completed in 1902, the Enid A. Haupt Conservatory is considered one of the most superb glasshouses of its time. It was designated a New York City landmark in 1973.
Conservatory restoration projects occur approximately every 20 years. EW Howell has worked with NYBG on other projects, including the construction of the new LEED Gold Edible Academy, which was completed in 2018.
The newly completed restoration, led by Jan Hird Pokorny Associates and Silman Structural Engineers, focused on the central dome that soars above the Palms of the World Gallery, comprising the cupola, upper dome, drum (or compression ring), and lower dome.
Interior scaffolding and a temporary horizontal work surface erected below the dome drum and an enclosed cylinder around the exterior of the drum and portions of the lower and upper domes enabled the work to take place efficiently while providing a weather-proof barrier to safeguard the tropical plants that remained in the Gallery below.
Using leading-edge materials and technologies, the restoration makes the building more energy efficient and increases its longevity while respecting its landmark status. The painted wood cladding around the drum and the wood cornice—constructed with rot-resistant, first-growth bald cypress that is now very rare—were replaced with cast and extruded aluminum components that are durable and require less maintenance.
Structural repairs to the compression ring were completed, and a new high-performance metal coating was applied to all structural members to protect them from future deterioration. Elements of the dome’s infrastructure that were upgraded included lighting, the electrical system and the heating system, including its custom enclosure.
In addition, the Conservatory’s public restrooms were renovated, including the addition of two single-use restrooms; improvements were made to the building’s exhibition and path lighting; and bluestone pavers in the palm dome and the Conservatory Courtyards were repaired.
Challenges & solutions
The structural steel compression ring of the Conservatory had exhibited some deterioration, which was the impetus for the timing of the latest restoration project. To enable the structural work to occur, a very specific sequence of work needed to be planned.
Deterioration of the wooden cornices was addressed through Landmarks approval of painted brushed aluminum replacements that made maintenance less challenging, given the height of the cornice. Featured are a wooden cornice, a cast aluminum replacement, and an aluminum cornice as installed with high-performance metal coating.
In addition, there was some deterioration to the wood cornice, and maintaining the exterior paint finish was challenging, given the height of the cornice.
Scaffolding for the project was a major challenge. The platform needed to be built to the level of the compression ring of the structure, with support towers positioned between the existing plantings. The next challenge was that the scaffold platform needed to create a weatherproof barrier during the winter months when the glass above the platform would be removed for the structural repairs to be completed.
The interior painting needed to be accomplished to give NYBG many decades of performance, as some areas are very difficult to access and will only get more difficult in the future as the palms grow. New exhibition lighting was installed while the scaffolding was in place and now allows NYBG more flexibility in designing for different exhibitions.
The palm dome had all its perimeter fin tube radiation and enclosures replaced during this restoration project.
In addition to The New York Botanical Garden, EW Howell Construction Group has become one of the partners of choice for some of the Tri-State area’s leading cultural institutions, including the Museum of the City of New York, Smithsonian Cooper Hewitt National Design Museum, Brooklyn Academy of Music, the Institute for the Study of the Ancient World, Brooklyn Museum, Christie’s Auction House and the Metropolitan Museum of Art.
“Renovations for cultural institutions present unique challenges and we were honored to be chosen by The New York Botanical Garden to restore the palm dome, one of New York City’s most iconic structures,” says Bob Zirkel, VP of EW Howell’s Arts & Cultural Division. “EW Howell has been privileged to work on projects that feature some absolutely stunning architectural design, and with input from arts and culture patrons who are some of the most passionate personalities in New York City.”
Bob Zirkel is co-VP of EW Howell Construction Group’s Arts & Culture Division, With 35 years of experience in the construction industry, he started at E.W. Howell as a project superintendent in 1985.