Is there a quick and lazy way to convert a prototype made of boxes model object to edit in Blender?

So, I been prototyping an developing a layout for a pinball game in unity, and I feel it is about time to made a proper model. Problem is, I am lazy, and want it as fast and easily as possible. I'm sure many others agree. So, is there a way to take all the boxes used to prototype the level, combine them into a mesh, then export it to an .obj or something to be properly re-modeled in a program like Blender?