Can I add $1500 to the cost basis of my second home without receipt for the parking lot repair in front of the garage?.

I spent $1500 to fix the parking lot in front of my garage from my second house.  I don't know where I put the receipt; so I think I lost it.  Since I sold my 2nd home last year, I am think to add $1500 to the cost basis of my 2nd home; but I don't have a receipt to prove it.  So what I can I do to resolve this?