One,   examines contract main body eligible, namely whether do lessor and tenant have corresponding requirement;  
2,   examines rented object eligible, namely whether does the building of lessor allow hack building for law, code;  
3, the formalities of house of careful make the rounds of the wards that rent is complete. Building property right proves to be not is lawful hack sufficient condition, still answer to deal with a building to rent licence by concerned regulation, the contract that rent also should undertake renting registering square but become effective.