Buildings
The building is the frame into which all the headquarters equipment is placed. It should have enough space for all equipment, plus extra space for the inhabitants and living quarters. if required. Let common sense decide if the territory is getting too crowded for the members, rather than any set rules. Heroes tend to be pack rats, acquiring bits and pieces from previous adventures, interesting technologies and half-finished experiments and mementos from old ex-foes. Were it not for villains scheming to destroy the HQs, heroes would have to hold garage sales in order to clear the equipment out.An easy way to determine if the building has sufficient room is to take an inventory of what is inside. List the rooms and the major equipments therein (no, don't bother about hairbrushes and the like). This gives your heroes the idea of where to find that cosmic ray-blaster when the Super-Skrull drops in unexpectedly.
Heroes seeking an HQ may rent an existing structure, buy an existing structure, or build their own. The FF have done all 3, starting out renting the top 5 floors of the Baxter Building, then buying the structure outright, and most recently building a new Baxter Building after the original was destroyed. Building your own HQ costs as must as buying, though the time must be figured using the building rules.
Buildings are defined by a number of factors: original purpose, number of floors, running water and power, how close it is to schools, etc. While all these are important, the key is size, cost, and material strength of the structure. These are noted on this table.