This gorgeous cube-shaped OUTrial House in Ksiazenice, Poland is by KWK Promes and takes an innovative approach to a house with a yard. Rather than staging the grass at ground level like other homes, the OUTrial House features a grass-covered rooftop.

We've seen a number of living rooftops and roof gardens designed for large residential and commercial properties, but the OUTrial House is the first I've seen that takes this approach to a single-family home. Check out some other green rooftops below.