First, I want to say that Alpha Delt will never be (or want to be) the biggest fraternity in the world(although we probably were....... in 1839
We have 30 chapters and affiliates, and don't plan on being any bigger than 45-50 chapters.
While we have some big houses, I don't think any break into the top 25, but I know a few hold big numbers, 80-90 guys, but they still use sleeping porches!
We do have some of the most valuable (as in most expense to replace) houses, with our Cornell house often cited as one of the most beautiful houses in the country. The GOTE Haus (chapter room), which is a separate building with no apparent entrance, would take 2-300,000 to replace. You could land a plane in the living room, and fit my chapter house in the lobby. The woodwork, the fireplaces......
Many of our northeastern chapters have gorgeous old mansions, built when stone masons and carpenters made dirt!