A rendering of Bjarke Ingels Group’s plan to remake the area around the Smithsonian Castle. National Capital Planning Commission members question the destruction of the formal Enid A. Haupt Garden. (Bjarke Ingels Group / Smithsonian Institution)

The Smithsonian Institution’s plan to redevelop the area around its iconic administration building, known as the Castle, by replacing its formal garden and relocating three entrance pavilions received mixed reaction from the federal agency that must eventually approve it.

The $2 billion plan is intended to increase the area’s visibility from the Mall, add such visitor amenities as restrooms and food service, and improve its accessibility and circulation.

In their first comments on the plan, members of the National Capital Planning Commission praised its attempt to better connect the buildings and gardens, but they questioned the demolishing of the Enid A. Haupt Garden and the uncertainty regarding the future use of the Arts and Industries Building. Several members suggested museum officials were too focused on the Mall and its tourists, to the detriment of city residents.

“You guys don’t exist in a bubble,” Commissioner Eric Shaw said. “How this [project] advances your mission needs to be clear.”

“There’s a lot that has to be addressed. It feels insular, and it needs to be a bubble burster,” added Commissioner Mina Wright.

The plan focuses on the 17-acre site that stretches along the southern edge of the Mall from the Freer Gallery of Art at 12th Street to the Hirshhorn Museum and Sculpture Garden at Seventh Street. Part of the Mall Historic District, the area includes the Arts and Industries Building and the underground Quadrangle Building, which houses the Sackler Gallery of Art, the National Museum of African Art and the S. Dillon Ripley Center.

Public comment on the project continues until Jan. 16. The museum hopes to secure approval for a final version in late spring.

The Smithsonian has devoted more than five years and $4.6 million on the plan, which was designed by Bjarke Ingels Group and presented with great fanfare in November 2014. Officials estimate the individual projects in the redevelopment plan would cost more than $2 billion and take 20 to 30 years to complete. The project was expected to begin with the renovation of the Castle in 2019. That target date has been delayed.

The Smithsonian’s newest version does away with the large, sloped entry to the expanded underground space — designs depicted in sleekly modern renderings by BIG that were roundly criticized by the public. This version no longer calls for demolishing the concrete wall along the perimeter of the Hirshhorn, but it still proposes relocating the entrance pavilions to the Sackler and African Art museums closer to the Mall. It also includes an underground visitors center, central utility plant and loading dock.

Commissioners sharply questioned the demolition of the Haupt Garden, which continues to draw criticism from the public.

“This is a hugely significant cultural landscape. It’s a sacred space for many people,” said Commissioner Beth White, who encouraged museum officials to listen to the public.

The vaguely defined plan for the Arts and Industries Building, a structure that remains mostly dormant despite a $55 million renovation, was another point of contention. Calling it “the elephant in the room,” Stephen A. Hansen, chairman of the Committee of 100 on the Federal City, asked the commission to press the Smithsonian on why it won’t consider the empty building for bathrooms and food services, thus sparing the cost and potential harm of putting those facilities underground. “The Committee of 100 encourages NCPC to press this point now in these deliberations and require the Arts and Industry Building to be better integrated in to the master plan,” he said.

Wright agreed. “It feels vague, and I don’t understand that,” she said. “You should allow this glorious building to have the comeback it deserves.”

Garden Club of America President Anne Neal Petri sought assurances that the Smithsonian would preserve the popular garden at the center of the site. Describing the Smithsonian plans as “vague and often conflicting,” she asked the commission to “go slow and get it right.”