Chicago Developer Uses Geothermal Field to Power Fulton Market Apartment Tower

A Chicago development team is using a geothermal system to power the first phase of 410 N. Elizabeth St. in Fulton Market, a two-tower multifamily project that will total 724 units. The first tower will have 383 apartments. Tree Street Group, Magellan Development Group and Mark Goodman & Associates are developing the project, and Tree Street principal Ted Weldon says the building runs entirely on grid electricity with no fossil fuel use.

The first phase uses 65 wells drilled roughly 850 feet deep, with about 22 miles of piping in total. The ground acts as a thermal battery: water loops through heat pumps that move heat into the earth in summer and draw it out in winter. The design developed by Infinite Energy Partners is projected to cut energy use by up to 60% and lower energy costs by 25%, according to the developers. Weldon estimates the building avoids 390 tons of carbon emissions per year.

The project is entering vertical construction with a targeted completion of March 2028. A second phase is planned about a year later to match leasing cycles, and Weldon expects faster drilling to shorten that phase's schedule. He says the approach is becoming more practical at scale because drilling has sped up and heat pumps have improved, and that it can help meet tightening energy codes.

For developers and lenders, the project is a test of whether geothermal can be financed in dense urban sites. Weldon says sites above about 30,000 square feet with a large podium and suitable soil may qualify.