Using the Magic Mansion as a place for crafting?

[MonkeySage]

Is there any practical way to do this? Conjure the mansion, then set up, for example, a room for crafting constructs, an alchemy lab, etc?

What I mean is, once you obtain the spell, it has a limited duration.

Once the spell ends, the mansion disappears, and presumably everything inside either disappears or is shunted back into the material plane.

What I'm wondering is, is there any way to guarantee that ongoing projects within the mansion won't be compromised?

The alternative in this case is to set up a mage tower, and my gm doesn't want to fuss with that.

[Karmea]

There was a Hold of Holding in Spelljammer (a magical doorknocker, that when attached to a door, opened to an extradimensional space). Ask your DM if you can craft/buy a similar item?

[ATalsen]

Is there any practical way to do this? Conjure the mansion, then set up, for example, a room for crafting constructs, an alchemy lab, etc?

What I'm wondering is, is there any way to guarantee that ongoing projects within the mansion won't be compromised?

By the way the Mansion spell seems to work, it would be a new mansion each time to you cast it, that you can make look the way you want:
"The atmosphere is clean, fresh, and warm...You can create any floor plan you desire to the limit of the spell’s effect."

It doesn't have the language that things fall out when the spell elapses, so you might want to figure out with your DM what happens before you use it - it would suck to be trapped inside with no way out.

Not sure if you are using Pathfinder or 3.5, but requirements for crafting are similar in both:
"The creator also needs a fairly quiet, comfortable, and well-lit place in which to work"

Which you can usually get in a room at an inn or even a rope trick, so the only benefit to a Mansion you could access multiple times is just storage. Most items you need to work on are backpack sized, and as noted you DO NOT need a big lab, just a quite place to work.

If you are working on something like a large golem, and are able to cast 7th level spells, then craft up (or buy) a Portable Hole (6 ft diameter, 10 ft deep no weight limit), and set you lab up in there.

Rent an inn room, or cast Secure Shelter, place the Portable Hole on a wall and you lab is ready with all materials you left in it.