The image is a square that isn't fully closed. At the top the line is broken like an entrance. Inside the square are some lines that partially section it off. The lines at the bottom look like a capitalized letter T.
This Floor Plan icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 6,000 icons, all in the same style and quality.