What cost basis to use when calculating an Asset's prorated sales price

Hello,

 

In 2021, I purchased a short-term rental property and sold it in 2022.  In 2022, I made $24K in improvements (new HVAC, new windows) to the house 5 months before I sold the property.

 

I am trying to calculate the respective gross sales price for the house and land.

I understand that I need to determine the percentage of the cost of each asset.


That said, should I be using the original cost basis of the house and land when determining the respective percentages?

 

Or should I use the adjusted cost basis of the house (original basis + 24K for improvements) when determining the respective percentages?

Note: The only asset is the house and the land. I have not other depreciating assets.


Thanks in advance