Apartment/house rental business

[dr. d]

We don't have a rental business but my question is kinda similar. My Uncle is renting our house and we gave it at a very good price. Previously kasi my Lola was paying a caretaker to stay in the house (all utilities shouldered by Lola) so now at least profit kami instead of expense. Anyway, my Uncle renovated the place and he gave us the accounting, I almost fell off my seat. Na shock nga ko I thought he'd do that for free kasi the rent is so LOW. He said that expense can be deducted from the rent so he only pays half OR he pays no rent until the amount is covered

50% of rent = 10 yrs for us to pay!
100% of rent = 5 yrs

My Uncle wants to buy the house kasi but we refused. I think he was hoping na he could deduct the renovation cost sa selling price

Now I don't know if we'll go for the 5 yrs or 10 yrs?

was there an agreement prior to the renovation, as to how accounts will be settled?

if you are unable to agree on compensation,
"fair market value of the rent" would be a good number.

also,
document the condition of the house. take lots of videos and/or pictures.