React Component Design
Generally if you want a more in depth review you should provide more code and a potential specifics you want to improve on; your code is very thin, and so it's a little difficult to help you expand on it, however, I would say that there's a few different things you can do to this to improve or follow a different direction forward.

Your use of pure components is good for BuildingUpdateBoxHeader and BuildingUpdateBoxBody as using primitive props is better for performance. However, using a content object inside your props for BuildingUpdateBox means React cannot shallow compare your props and is unable to determine when not to rerender the component, causing potentially wasted rerenders.

I would recommend trying JSS (css in js) to embed your styles directly in your application for an alternate solution to specifying className manually. This couples your css with its implementation rather than needing to update both the css &amp; js when you modify them.