SECTION 1. The administrator of the San Lazaro estate is hereby authorized, upon approval of the Secretary of the Interior, to execute leases covering lands belonging to said estate in accordance with the following conditions:
1. All lands used for building purposes, upon which the tenants have constructed, or may hereafter construct, buildings to the value of not less than two thousand pesos, a lease term of ten years.
2. All lands used for building purposes upon which the tenants have constructed, or may hereafter construct, buildings to the value of more than two thousand pesos, two additional years for each additional one thousand pesos or portion thereof: Provided, however, That no lease shall be executed for a longer period than fifty years.