According to the Interim Measures for the Administration of Public Rental Housing in Chongqing and the Detailed Rules for the Administration of Public Rental Housing in Chongqing, when the lease contract expires, the lessee shall withdraw from the public rental housing; If you need to renew the lease, you should apply 3 months before the expiration of the lease contract. Those who meet the requirements after examination shall re-sign the lease contract and give priority to renting the original leased house. Chapter VIII Management of Sale Article 40 After the lease expires for five years, the lessee may choose to apply for the purchase of public rental housing. Forty-first public rental housing sale price is based on the comprehensive cost, the specific price is determined by the municipal price department in conjunction with the municipal housing security, municipal finance and other departments, and regularly announced to the public. Forty-second purchase of public rental housing, you can choose to pay in one lump sum or by installment. After one-time payment, no rent will be paid; When paying by installment, the unpaid area shall be paid the rent as required. Article 43 A purchaser shall sign a sales contract with the property owner or the trustee in writing, specifying the payment price, payment method, repair responsibility and other rights and obligations of both parties, and register with the housing and land ownership department after paying the full amount. Forty-fourth the purchase of public rental housing shall not be leased, transferred, given away and other market transactions, Chongqing public rental housing can be inherited, mortgaged. Article 45 After the purchased public rental housing is mortgaged, the mortgage value shall not exceed 70% of the original value of the purchased housing. Article 46 If the purchaser obtains other houses in the place where the public rental housing is purchased by means of purchase, gift or inheritance, or needs to transfer or mortgage them for special reasons, the government will buy them back at the original sales price plus the current interest on bank deposits in the same period.