Construct Advancement

[Mirakk]

Question for you Artificers out there. If someone were to build a golem, can they advance its hit die after creation? Or are you locked into keeping the golem you created until it is no longer of any use to you? Typically there is a cost given for each hit die for making advanced versions of the golem, but I don't believe that confers the ability to advance the golem after it's been built.

Confirm/Deny?

[Ferronach]

This is based purely off of my own experience not off of a book (sadly at work and without books):

Yes. In the past, my DMs and myself (as DM) have ruled that by "adding new pieces" to the golem, you are able to enhance it/up its AC/up its HP etc.
For AC you would need to add some sort of shielding, magical enhancements require focus crystals (or similar), more HP depends on the golem itself but could be linked to more AC if your DM agrees.

As I said this is from my experience only and may differ drastically from RAW/rules.

[Psyren]

Golems are magic items by RAW, and magic items can be improved.

The specifics of this are an exercise left to the reader.