Section 20. Except as otherwise provided by law, any sale of real property shall be awarded, after advertisement for bids, to the bidder who is the highest responsible bidder. The department shall have the right to reject all bids and to read-advertise for bids. Before any real property shall be so sold or conveyed, notice that such real property is for sale shall be publicly advertised in 2 daily newspapers of general circulation published in the city of Boston and, if such real property is located in any other city or town, in a newspaper of general circulation published in such other city or town, once a week for 3 successive weeks. Such advertisements shall state the time and place where all pertinent information relative to the real property to be sold or conveyed may be obtained and the time and place of opening the bids in answer to such advertisements and that the department reserves the right to reject any or all such bids. All bids in response to advertisements shall be sealed and shall be publicly opened by the department. The department may require, as evidence of good faith, that a deposit of a reasonable sum, to be fixed by the department, accompany the proposals. This paragraph shall not be applicable to any sale of real property by the department to the commonwealth or any city, town or public instrumentality nor to a sale of real property which is determined by the department to have a fair market value of $50,000 or less; provided, however, that the department shall declare the property available for disposition and shall specify the restrictions, if any, placed on the subsequent use of the property.

The department may sell buildings or other structures upon any lands taken by it or may remove the same and shall sell, if a sale be practicable or, if not, shall lease, if a lease be practicable, any lands or rights or interest in lands or other property taken or purchased for the purposes of this chapter, whenever the same shall, in the opinion of the department, cease to be needed for such purpose.

Notwithstanding this section, section 46 or any other general or special law to the contrary, the department may convey, or lease for a term not to exceed 198 years, air rights within the parcel known as Massachusetts Turnpike Parcel 15 to the designated developer of that parcel or its nominee. The parcel is located in the city of Boston and bounded by Cambria street to the south, St. Cecilia street to the west, Boylston street and private property to the north and Dalton street to the east. The boundaries of the air rights conveyed or leased shall preserve the department's ownership of the turnpike roadway and adjacent rail tracks and air space above the roadway and rail tracks as considered necessary and desirable by the department for its transportation purposes. Any such sale or lease may include air rights above streets owned by the department that adjoin the parcel and the department may grant a developer or its nominee rights and easements to install and maintain foundations, walls and other appurtenances below the air rights so conveyed or leased, all on such terms and conditions as the secretary of transportation or general counsel deems necessary or desirable. Any such sale or lease shall be at the then-fair market value of the air rights as determined using customary appraisal practices in the commonwealth and shall not be subject to the requirements of this section. Any such sale or lease shall be subject to: (i) the department reserving all easements and rights needed for its transportation purposes; (ii) recognition by the developer or its nominee that the department's transportation needs remain paramount; (iii) compliance by the developer or its nominee with the department's requirements for indemnification, covenants not to sue and releases relating to negative impacts from development above the turnpike and rail lines; (iv) the developer fulfilling its commitment to the city of Boston's inclusionary development policy by building off-site units in the Back Bay or Fenway and Kenmore sections of the city of Boston or the South End planning district, with a preference for locations within 1/2 mile of the project site; and (v) such other terms and conditions as the secretary of transportation or the general counsel determines are necessary or desirable. The developer or its nominee shall be obligated to take such premises ''as is, where is'' with all existing site conditions, including existing environmental conditions. If the department of transportation completes such a sale or extended lease and if the developer's mandatory inclusionary development policy contribution in combination with available commonwealth funding is insufficient to construct 1 or more viable projects totaling a minimum of 51,840 square feet of affordable housing within the geographic area established in clause (iv), the department of transportation shall transfer an amount of up to 20 per cent of the sale or lease proceeds to the Boston Redevelopment Authority as gap financing to be used exclusively for the construction of affordable housing. If the Boston Redevelopment Authority certifies that 1 or more viable projects totaling 51,840 square feet or more within the geographic area has been identified, the department of transportation shall instead transfer an amount equal to 12 per cent of the sale or lease proceeds to increase the number of affordable units in those projects. In neither case shall the department of transportation funds or other commonwealth funds be used to subsidize or offset a developers' inclusionary development policy commitment.