Accounting treatment of construction of building when the land is not ours

What are the terms based on which father in law has given permision to use first floor, specifically time period?

Please note that : "A perusal of section 27(iiib) and 269UA(1) leave no room for any doubt where the period of lease is more than 12 years the lessee is deemed to be the owner of the property for the purpose of assessment under the provisions of the I-T Act."

Thus you may capitallize the expenditures under fixed assets.