To prepare for our next kitty, a Maine Coon, I built this Kitty Condo extra heavy and extra sturdy. Maine Coons are big, heavy, and strong. We couldn't find any commercial products that seemed large enough or strong enough.
I started with plans I found on the internet, then doubled the base and bed materials. I extended the center shelf farther rearward to make it easier for our nearly 19-year-old year cat, Lucy, to make her way up to the second level bed. Also used more fasteners than the original plans called for.
I'll post more pictures as it comes along.