Developer John Buck is feuding with the board of his East Lake Shore Drive co-op. The issue at hand is how big Buck’s unit in the 10-story, 13-unit building, which is east of the Drake Hotel on one of the city’s most exclusive residential blocks. The answer determines whether the board can increase the developer’s assessment from $13,700 to $22,300, according to Chicago Real Estate Daily.

If the increase occurs, Buck, chairman and CEO of Chicago-based John Buck Co. and best known for developing downtown skyscrapers such as 155 N. Wacker Drive and 190 N. LaSalle St., would be paying $268,000 annually.

The dispute began in 2008 when the board voted to change the way each co-op is assessed its share of building expenses, shifting to a calculation based on the square footage of each unit.

After the board measured each of the units, it determined the Bucks’ home totaled 9,672 square feet, including the enclosed roof deck. However, the Bucks say the unit is just 6,903 square feet, based on a measurement by a surveyor the couple hired.

The rooftop deck should not be included because the Bucks separately pay all utilities, taxes and other for the deck, the complaint says.

Just last month, Buck and his wife, Kathleen, sued the board because, as the couple alleges, the board’s measurements are wrong and refuses to correct them.

“We’ve been a little perplexed as to why we’ve gotten such resistance (from the board),” Bradley Nelson, a partner at Schopf & Weiss LLP, told Chicago Real Estate Daily. “We’ve never been able to get a good reason from them.”

Holly Hunt, president of the co-op board as well as Holly Hunt Enterprises Inc., declined to comment, according to an employee at her Chicago-based firm. The co-op board’s lawyer, Mark Pearlstein, a partner at Chicago law firm Levenfeld Pearlstein LLC, did not return a message requesting comment either, according to Chicago Real Estate Daily.