I tried a few different ways, but the "has been Xing" keeps coming up.
Which has been undergoing renovation for a year.
Which my uncle has been renovating for a year.
It applies to the present, and it's an ongoing process, so the present perfect continuous (I think that's the right name) does seem to be necessary.
I suppose something like ", nearing the end of a year-long renovation by my uncle," would work.
Student or Learner