Developer Equity One goes before the Cambridge Historical Commission on Thursday for permission to gut the buildings that house Curious George and Urban Outfitters and add three new floors to create a mall called the Harvard Collection.

Equity One, which says it specializes in "the redevelopment of high quality shopping centers in supply constrained markets," spent $85 million last October to buy 1-7 and 9-11 JFK Street and 18-20 Brattle Street.

Under the plans submitted to the Historical Commission, the space now occupied by the Curious George bookstore would be replaced by a building lobby, a stairway and an elevator. The building is also known for the Dewey, Cheetham & Howe headquarters of Car Talk.

Atop the two buildings further away from the square, the company proposes two new floors of glass-enclosed space - which would then be connected to the existing Curious George building to create "contiguous retail and commercial floors." And then, atop that and extending onto the roof of the current Curious George building. would be a similarly glass-enclosed "pavilion," capped by a large skylight. The company's filing does not specify what the topmost floor would house.

Equity One says it would retain the existing brick facades - and try to restore many of the windows to their original configurations as part of its "complete renvoation and restoration" of the buildings.

The commission's hearings begin at 6 p.m. at Cambridge City Hall, Sullivan Chamber, 795 Massachusetts Ave. There is not a specific time for the Harvard Collection hearing.

In a conference call with investors last fall, Equity One CEO David Lukes explained why the company bought the three buildings:

This property is a rare find and it checked all three of our strategic boxes, overwhelming demand, near-term below market expirations and supportive zoning. Over 20,000 people a day use the T-Stop across the street and 8 million people visit Harvard Square every year and all the leases in the project are short-term with expirations occurring before the end of 2017. Just as important, we believe our investment in this asset will well exceed our cost of capital and we'll be producing these returns in one of the most coveted urban retail corridors in the country.

Proposed view from the intersection:

Schematic of exterior changes:

Sign in Curious George window:

Equity One's plans, filed with the Cambridge Historical Commission (4.6M PDF).

Equity One's application to the commission (539k PDF).