In my view the Board of Estimate erred when it disapproved the BSA decision and Special Term by its order merely compounded that error. The Board of Estimate’s reviewing authority is restricted and unless it can be said the BSA’s action was totally unjustified, the Board of Estimate was without authority to alter it. The record discloses the City Planning Commission did not object to the proposed variance and that in reaching its unanimous decision the BSA, aware of the criteria to be met on an area variance application, conducted hearings, had a committee inspect what it concluded was, because of its narrowness, a unique physical site, gathered the relevant financial data, considered the views of surrounding landowners, none of *119whom voiced objection, and then issued fairly extensive and detailed findings.
On the issue of uniqueness the BSA observed the subject lot was "extremely narrow” having only 16 feet 8 inches of frontage, whereas the Zoning Resolution was predicated on lot sizes having 40 feet frontage. Whether a lot is unique or not is a matter of interpretation and judgment. The BSA, a body of experts charged with implementing the Zoning Resolution, determined the subject lot was "uniquely undersized” and that finding has an obvious basis in the record. The fact that adjoining lots may be the same size does not detract from this conclusion for the lot’s uniqueness emanates not from a comparison with adjoining lots but from a comparison with the Zoning Resolution’s lot size requirements.
Since an area variance was sought, only practical difficulties were required to be shown (cf. Matter of Envoy Towers Co. v Klein, 51 AD2d 925), and were. The BSA found petitioner was unable to make use of space in an adjacent building he owned because he had been prevented by the rent control office from evicting the tenant, and also noted that if the offices were relocated the owner could not amortize his investment or either obtain the necessary rents to keep the building viable or its market value. Furthermore, the BSA was furnished information by an independent certified public accounting firm which documented the financial loss which would accrue to petitioner if the subject lot was developed without the requested variance.
There was ample evidence in the record to also support finding that the essential character of the neighborhood would not be altered by the variance. Engaging in medical practice was a permitted activity and extension into the rear yard was a permitted obstruction under section 24-33 of the Zoning Resolution so long as the building height did not exceed one story nor in any event 23 feet above curb level. Here the completed structure would have resulted in two stories totaling only 17 feet in height.
Birns, J. P., Bloom and Lupiano, JJ., concur with Fein, J.; Yesawich, J., dissents in opinoin.
Judgment, Supreme Court, New York County, entered on January 23, 1979, affirmed. Respondents shall recover of appellant $75 costs and disbursements of this appeal.