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 is a Floor Plan icon. We've made it in iOS style
, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,700 icons, all in the same style and quality.