The research departments didn't look that much different from the office spaces up above ground level, but Maxwell explained why they were below ground easily.
Scents.
There were less scents that could conflict with research underground. With above ground, there was a chance that windows or doors or anything like that could sneak into a chamber and even the smallest amount could change the outcome of a test.
It explained the giant de-scenting machine that was the front door to several departments that Andrew and Maxwell passed. Maxwell didn't show Andrew those, and the reason was simple.
Andrew was doused in Maxwell's pheromones. Practically a shield against all other pheromones since that was what Andrew liked, and Michael had recommended. Anything that would take away those pheromones before Andrew was ready was a bad plan.
Max was saving Richard as a nice surprise for Andrew. Precious.