Barring usage of the Hermetic Architecture Mystery Virtue's option whereby you make several enchanted items and put them in niches throughout a structure to enchant the whole thing, you generally need something to be within your laboratory in order to make it enchanted. Does your laboratory count as within itself for purposes of allowing you to enchant it? Or would you need to, say, build another, bigger lab around your lab to enchant your lab?
I would say yes, and in fact, Hermetic Architecture isn't needed at all, since the you can enchant the floor or one brick of the wall or something like that and it rules all the lab enchantments.
As a SG I'd allow the lab to be enchanted as a "thing" from the same lab. Doing the opposite is a little pedantic.
Agreed!
The Hermetic Projects book seems to assume that whatever you're enchanting must be entirely contained in the laboratory. Also keep in mind that a laboratory is often not the entirety of a structure, so the parts not considered to be 'in your lab' could not be enchanted. The whole point is somewhat moot, however, as enchanting devices to have Structure level effects is entirely possible. There's little reason to enchant a whole building other than possibly saving one single magnitude on range of the effect (Personal instead of Touch), and many reasons to not enchant the building (devices can be re-located as desired).
If your lab is a single roomed building, it's probably safe to assume that the 'entire' building is in the lab - after all, the walls, roof and floor are indeed part of the laboratory, given how they are necessary for the 'standard' lab, and how room and structure based spells encompass these things as well.
The shipyard and tower chapters in Hermetic Projects take that guidance from the core rulebook (I think). However, it does then provide examples of how you can get around it. For instance, the shipyard is a very large laboratory that happens to be open to the elements. I'm sure the tower chapter has a mobile lab that can be moved from room to room and is treated like an inside-out lab - whatever room the lab is erected within is considered to be "fully inside" the lab.
I can thoroughly recommend enchanting a laboratory. One of my mages did so, binding a spirit of magic into it. Then I added all sorts of rego and muto effects so the spirit could animate it, changing aspects as needed for each project. The spirit also learned Magic Theory (not strictly RAW in 5th ed) and then acted as my lab assistant.
That particular character was unable to have a familiar, so the SG was happy to bend certain rules to enhance the story since it was still weaker than the equivalent time spent on an actual familiar and on 'normal' lab enhancements.
It made for a unique lab and 'feel' for that character whether he was inventing anything or simply reading books - with his friend for company, who would offer opinions on the books and arts being studied, rather than anything generic.