Building Project

Welcome to Dalton’s community resource page for our building project. As of September 2019, the project has been completed: We have added two stories atop the 89th Street building for a STEM (Science, Technology, Engineering, Math) facility and have completed selective renovations within the existing building to help students develop 21st-century skills. The project will not increase enrollment.

Project Scope

Our Transformative Building Project

Following 2 ½ years of construction, Dalton’s new facilities opened September 2019. This was an exciting, once-in-a-generation opportunity to reimagine our entire school for the 21st century. And this investment offered an unprecedented opportunity to connect Parkhurst’s pedagogical foundation to the physical space facilitating project-based, experiential learning. From top to bottom, this project ensures that we can serve each student in inspiring, new ways. 

Building Highlights

We added a 12,200 square foot, two-story rooftop expansion to our existing 12-story 89th Street building. Designed by Architects Skidmore, Owings & Merrill (SOM), our new facility includes a dedicated STEAM facility and open space for collaborative, interdisciplinary meetings and community events. The expansion gives us the flexibility to build on the success of our programs in the STEM fields, robotics, and transdisciplinary work.
Recently named the Ellen C. Stein Center for Collaborative Study, our thoughtful, forward-looking design encourages interaction and chance encounters between students, faculty, and disciplines. The open communicating staircases, informal nooks, and pockets of seating allow for moments of spontaneous, serendipitous conversation, while movable classroom walls encourage collaboration, creativity, and exploration.
This flexible place of new learning enables methods of teaching not yet envisioned and fosters new connections between faculty and students. Potential curricular innovations are boundless with the addition of a robotics field, prototyping space, an engineering lab, computer science & digital media rooms,a machine room, a nutritional science kitchen, a stunning greenhouse skylight, and glass-enclosed art studios adjacent to a dance studio – which doubles as a black-box theater. Ample space is also available for art exhibits and science competitions.
With an eye toward advancing Dalton’s mission – the master plan re-organized the building into three simple programmatic groups:

  • Interdisciplinary Hub - On top, the STEAM center, a vibrant hub provides a central place for science, engineering, and art and promotes interdisciplinary dialogue, dynamic exchange of ideas, and meaningful collaboration.  
  • Academic Core - The middle, or academic core, is the hive of instructional spaces for both middle and high school students.  
  • Student Resources - The base of the building encourages community building with student resources such as the newly relocated, rejuvenated library, the lobby, the cafeteria, theater, and music.  
Dalton Founder Helen Parkhurst called on Dalton to be progressive and adaptive, and Dalton has always innovated to serve our students in imaginative new ways. This evolution will ensure that Dalton lives up to its mission and lives out its values. It places equal emphasis on all disciplines – arts, sciences, humanities and is mindful of our historical emphasis on music, dance, theater, and visual arts.
By balancing holistic design and functional needs – along with a firm commitment to educational innovation – we celebrate Dalton’s legacy and proudly go forth into the future.


List of 8 frequently asked questions.

  • How can I stay informed about project and construction updates?

    The School has set up a dedicated a phone line, email address, and website. Please direct questions or comments to our main point of contact, Michael Mezo, Director of Facilities at 212-423-5352 or email These inquiries will be answered as soon as possible. If you prefer, please subscribe to the mailing list (see sign-up section to the right) for timely information delivered directly to your inbox. 
  • Will the streets be closed during construction?

    As required for safety, the street is expected to close temporarily during crane operations in coordination with the NYC Department of Transportation (DOT). Emergency vehicle and pedestrian access will be provided at all times.
  • How will you manage traffic on 89th Street?

    The School will position a flag person on Lexington Avenue and Park Avenue when the street closes for crane operations. During regular construction periods, lanes will remain open for regular traffic flow.
  • What are you doing to mitigate the noise?

    The construction manager will monitor noise levels to make sure the project complies with Department of Environmental Protection (DEP) requirements. In addition, the construction manager’s noise mitigation plan prohibits truck idling and requires the use of sound blankets to minimize noise from heavy equipment.
  • What is the School doing to address light pollution?

    All school spaces are equipped with motion sensors. Glass enclosed spaces are also equipped with downlighting and shades to minimize brightness.
  • Will there be security during construction?

    The School will have uniformed security and video cameras on site during construction.
  • How will Dalton protect our building?

    As required by the Department of Building’s (DOB), the School will erect a sidewalk bridge to protect pedestrians. Roof protection will also be provided as required by DOB.

Project News & Look-Aheads

List of 3 news stories.

  • Expected Construction Activities: September 2019

    The project team wrapped up interior construction work for the successful start of school on September 9.  We thank our neighbors for your continued patience through the completion of our construction project.  
    The following is a summary of expected construction activities for September 2019 including relevant information about the exterior work and DOB permitted construction hours.  We are currently wrapping up a few exterior masonry patching items where the hoist was located.  We anticipate the sidewalk bridge to remain up through the month of September for safety until we receive DOB approval to remove.
    Read More
  • Expected Con Edison Work: 8/23 and 8/24

    Con Edison will work in the street to provide upgraded electrical service to the 89th Street building. We anticipate they will be working on 8/23 and 8/24 from 3:00 PM to 11:00 PM each day.  We apologize for any noise this causes. Unfortunately, cannot control Con Edison's schedule.
    Read More
  • Expected Construction Activities: Summer 2019

    The following is a summary of expected construction activities for Summer 2019 including relevant information about the exterior, interior work, and DOB permitted construction hours.
    Read More

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Please direct questions or comments to Director of Facilities Michael Mezo at: 212-423-5352 or

These inquiries will be answered as soon as possible. (Please direct non-emergency reports to 311 and emergencies to 911.)


212.423.5200 |
(K-3) 53 East 91st Street, New York, NY 10128
(4-12) 108 East 89th Street, New York, NY 10128