Just in time for Earth Day tomorrow—and the March for Science—New York City buyers in the market for eco-friendly apartments have loads of properties to choose from this open house weekend. Here, a sampling of apartments hosting viewings this weekend:

2231 Adam Clayton Powell Boulevard, Apartment 611. A two-bedroom, two-bath in Harlem with an in-unit washer and dryer, and located in a LEED-certified building with its own co-generation plant. Asking price: $1.035 million. Open house: Friday, April 21, 11 am to 5 pm; Saturday, April 22 and Sunday, April 23, 12 noon to 4 pm.

262 Bond Street, Apartment 2. This condo, tucked in a converted electrical warehouse in Gowanus that's been LEED-certified, has three bedrooms and two-and-a-half bathrooms. Asking price: $2.1 million. Open house: Saturday, April 22 and Sunday, April 23, by appointment only

400 East 67th Street, Apartment 22C. Sitting up high in the Laurel, a LEED-certified tower on the Upper East Side, this three-bedroom has three-and-a-half bathrooms, 10-foot ceilings, large windows, and views for miles. Asking price: $3.195 million. Open house: Sunday, April 23, 12 noon to 1:30 pm.

151 East 85th Street, Apartment 12E. This 2,480-square-foot three-bedroom, located in the Upper East Side's first LEED-certified building, sits in a corner and has three bathrooms. Asking price: $5.995 million. Open house: Sunday, April 23, 12 noon to 1 pm.