Center on Sustainable Communities (COSC), Des Moines Area Association of Realtors (DMAAR) and Iowa Association of Realtors will present two workshops on the uses and benefits of green categories recently added to the DMAAR residential multiple listing service database. A session for homeowners, buyers, builders and renters will be 5:30 to 7:30 p.m. Dec. 11 at Hoyt Sherman Place in Des Moines. Registration is $5 for COSC members and $10 for nonmembers. A session for real estate professionals, lenders, appraisers and attorneys will be 8 a.m. to 5 p.m. Dec. 12 at the Iowa Association of Realtors, Clive. Continuing education credit is available. Registration is $100, with a $50 discount to the first 50 members who register. Registration information is available at www.icosc.com, info@icosc.com or 277-6222.