For more than a year, a pair of oversized lots at Lake Shore Drive and Wellington Avenue have been the the North Side’s only on-the-market vacancies for lakefront mansion-building.

The oversided lots—$3 million for one measuring 34' x 200', $3.5 million for the one at 37' x 186'—are at a land holding known as Lake Shore Estates, previously the site of a church, with zoning that allows for multi-unit, townhouse, or single-family structures with a maximum height of 47 feet. The slightly shallower site is priced higher because of an easement enforcing a wide berth between it and the two houses to the south.

CMK Realty, the development company that owns the land, is offering them individually or together, but there’s no discount in bundling. It’s merely a nod to new interest from condo builders.

This makes sense, given the market’s favorable treatment of boutique ultra-luxury condo development in the last year, and it seems unlikely that a small condo building would unnerve the neighbors. This is high-rise country, after all.

An 8- or 10-unit condo building would suit the combined lots, and if a developer pays roughly the asking price on the land—$6.5 million—I estimate that condos would end up at $2 million or more, or as high as $1,000 per square foot, based on what I've observed in the high-end market.

At $6.5 million for both, the land is aggressively priced, although there aren’t many similar sites to compare it to. Seven of nine Lake Shore Estates lots have sold since 2007, all but two sprouting very large houses. In addition, the historic Meeker Mansion at the site’s northeast corner was converted to four duplex condos and sold out in 2012.

According to public records, the other lots at Lake Shore Estates, most of similar size, went for between $1.85 million to $2.63 million, with the last selling in July 2014.

Why is it taking so long for the last two lots to sell?

“A lot of prospective buyers test the waters,” says Jim Kinney, vice president of luxury home sales at Baird & Warner, “then realize how much easier it is to buy an existing home given the time required for design, permitting, and construction, and the high probability of cost overruns.”