The owner may petition an additional charge to be added to the maximum rent and ceiling rent for the provision of substantial capital improvements or increases in services. The owner shall notify each tenant by certified mail of the total cost of the proposed or completed capital improvement or increase in services, the average cost per apartment of the improvement and the amount of the additional charge being sought from each tenant. The owner seeking such an additional charge shall petition for the same from the Rent Control Board, which shall determine, after public hearing, whether said improvement or increase in services is substantial and whether the proposed additional charge is fair and equitable; and, upon its finding to such effect, it shall permit such increase to take effect as it deems to be fair and equitable in the circumstances. For the purpose hereof, the replacement by an owner of worn, obsolete or deteriorated appliances, equipment, structures or facilities shall not be deemed a capital improvement. If an owner and a tenant shall mutually agree on substantial and extraordinary improvements to be made to a single apartment for the sole use and benefit of a single tenant, said owner and tenant may file a joint petition with the Rent Control Board, setting forth the nature of the improvements and the additional rent, agreed upon between them. The Rent Control Board shall approve said additional rent increase if it finds the same to be reasonable and fair and equitable as between the owner and tenant after full disclosure by the owner of all material facts relating to the nature, cost and quality of same.