At a presentation of plans to add three floors to the five-story building at 66 Reade Street in TriBeCa and convert it to 8 residential condominium apartments, Roger Byrom, the co-chairman of the Landmarks Committee of Community Board 1, extolled the virtues of "the spirit of invisibility"

David Prendergast of the architectural firm of Prendergast Laurel Architects made a presentation of the plans of Jean Hieber, the building s owner, to the committee and said that the proposal uses only 5,000 of the 6,000 available development rights for the site.

Mr. Prendergast presented pictures that indicated that the slanted addition would not be visible from the street, but several members of the committee including Mr.Byrom were not convinced.

Mr. Prendergast argued that by lowering the existing roof level by four feet and slanting the additional floors that the roof-top addition would not be visible from the street.

The existing building has a 10-foot rear yard, but Mr. Prendergast indicated that the new top three floors would be setback 30 feet from the rear property line to comply with zoning regulations.

The committee held off a vote on the application that goes before the Landmarks Preservation Commission so that it could further examine the visibility of the proposed addition.

The building is between Church and Broadway.

Many of the applications for certificate of appropriateness from the Landmarks Preservation Commission are for roof-top additions to buildings in historic districts and many such additions are relatively non-descript and bulky additions that are setback from the front of the building so as to be not visible from the street.

The commission and preservation and civic groups have tended to closely examine whether such additions are visible from many directions, but have not less concerned with the architectural merits of the additions.

Mr. Prendergast's addition is a very dramatic cascading glass addition that while not stylistically related to the base of the building, or its immediate surroundings, is a dramatic and coherent architectural addition.