(a) where real property is subdivided into not more than four lots, plots, blocks, sites or units that conform to the applicable planning and zoning regulations or ordinances of the city, town or village, as the case may be, and such subdivision does not involve the laying out of a street or the extension of a previously laid out street, the owner or agent may make written application to the planning commission or planning authorities having jurisdiction for a waiver of the filing requirements hereunder upon forms supplied by the appropriate planning commission. Such a waiver may be granted by such planning commission or planning authorities after determining that such subdivision plat is in compliance with this section and with the zoning and planning regulations of the city, town or village, as the case may be, in which the property is located. The request for a waiver shall be acted upon without a public hearing within fifteen days after the filing of the application unless such period shall have been extended by consent of the applicant. Where real property is capable of being subdivided into more than four lots, plots, blocks, sites or units that conform to the applicable planning and zoning regulations or ordinances of the city, town or village, as the case may be, and such subdivision does not involve the laying out of a street or the extension of a previously laid out street, the planning commission or planning authorities having jurisdiction may, in the sole discretion of such planning commission or planning authorities deny such waiver application and require the filing in the office of the clerk of Nassau county a map or maps of such real property, subject to appropriate conditions as in the judgment of such planning commission or planning authorities as are requisite in the interest of the public health, safety and general welfare; or

(b) where a subdivision map has been filed prior to January twelfth, nineteen hundred forty-five, and alterations made thereon do not involve any change, or extensions of previously laid out streets and where the only alterations are changes in lot boundaries which are made solely for the purpose of adhering to applicable zoning regulations, it shall not be necessary to file such altered map or obtain a waiver therefor; or

(c) where there is a conversion of an existing structure into units, which structure: (1) was in existence and legally occupied prior to August fifth, nineteen hundred eighty-seven; and (2) where title to said units is to be held in a condominium, cooperative or mixed form of ownership; and (3) the use thereof is in compliance with the zoning and planning regulations of the city, town or village, as the case may be, in which the structure is located. As used in this section, the term "units" shall include space used or to be used for either residential, commercial, mixed or other use whether title is held in fee simple, a condominium, cooperative, or mixed form of ownership. It shall be unlawful, after a map or maps of such property has been filed, to subdivide said property in a manner other than as shown on said map unless said map has been amended and approved in accordance with the provisions of subdivision six of this section. 2. Such map or maps must be thirty-six inches by forty-eight inches or less in size, drawn with pen and ink upon tracing cloth or printed on mylar upon a scale of not more than one hundred feet to the inch and oriented with the north point at the top of the map. At no time shall the north point vary more than twenty degrees east or west of the perpendicular border. 3. In case the lands sought to be shown upon the map are too extensive to be shown upon a map thirty-six inches by forty-eight inches in size, then a key map thirty-six inches by forty-eight inches in size, drawn upon a reduced scale, but without detail, showing the entire quantity of land, subdivided into units embracing the entire map, shall be made and filed, and each subdivision or unit shall be shown upon a separate map. 4. Said map shall set forth the courses, measurements and adjoining property owners with sufficient definiteness to determine the location of said property, and upon each map shall appear the name of the record owner and the name of the subdivision as stated by the owner and said name shall be approved by the county clerk as a name not so similar to the name appearing upon any filed subdivision map as to deceive or mislead the public as to the identity of such subdivision. 5. Upon each and every of said maps shall appear the name or names of the town or towns, city or cities, incorporated village or incorporated villages in which said lands are located wholly or in part, and endorsed thereon shall be a certificate of the licensed land surveyor who made or caused the said map to be made, certifying that the map or maps were made from an actual survey of the property that was performed by or under the direction of said licensed land surveyor and the date of the completion of the survey. Said certificate shall state that stone or concrete monuments have been set at not less than two corners of every street intersection as indicated on such map or maps and that the lands shown thereon have been monumented in a manner to indicate the distance from the nearest established street, avenue, road or highway, provided, however, that where the planning board or other governmental agency having jurisdiction over the approval of said maps has required the subdivider to deposit with the town or local governing body a performance bond or bonds to secure the installation and completion of all site improvements, including setting stone or concrete monuments in the streets as aforesaid, and simultaneously with the filing of said map the subdivider files with the county clerk a written certification from the town or local governing body that such bond or bonds have been duly deposited and accepted by the town or local governing body and that said bond or bonds expressly include the setting of stone or concrete monuments as aforesaid, the said surveyor's certificate may state that stone or concrete monuments will be set at not less than two corners of every street intersection as indicated on such map upon completion of the installation of said streets and that the surveyor shall execute and deliver a further written certification of the completion of such monumentation to both the county clerk and the town or local governing body prior to and as a condition for the release of said performance bond or bonds. 6. Before such filing each and every of said maps shall be approved by the planning commission or planning commissions having jurisdiction in the area embraced within said maps in accordance with the regulations of such planning commission or planning commissions and the approval of such planning commission or planning commissions shall be endorsed thereon. 6-a. Before such filing each and every of said maps shall have endorsed thereon the consent to such filing of the mortgagees of such real property. 7. The planning commission or planning authorities having jurisdiction shall not approve any such map until the commissioner of public works of Nassau county has endorsed thereon a statement that he has approved plans for grades of the streets, avenues, roads or highways shown on such map, and the drainage thereof. The commissioner of public works may require that separate and distinct plans for the grading and drainage be prepared. Such plans shall show sufficient data to enable the commissioner of public works to determine the adequacy thereof. He may require any changes in grades or plans which he deems necessary to make such grades or plans conform with any general or comprehensive plan adopted for the county, or to serve the best interests of the county as a whole. Upon his approval of plans for the grades and drainage for the streets, avenues, roads or highways shown on said map he shall endorse such approval on the plans submitted to him, or as they shall have been revised, and shall file same in his office, and shall file a print thereof in the office of each planning authority having jurisdiction. He shall further endorse on the map submitted to the planning authority for approval a statement that he has approved grades and drainage for the streets, avenues, roads or highways shown thereon, in accordance with detailed plans on file in his office. 8. At the time of filing such map with the county clerk an abstract of title and tax search of all of the property shown on said map together with a certificate of title, certifying to the county of Nassau the name or names of the owner or owners of said property together with all liens thereon, shall be delivered to the county clerk and filed in his office. Such abstract and search shall cover a period of not less than the twenty years immediately preceding the date of the certificate and such certificate shall be made by a title company duly incorporated and authorized to transact business in the state of New York or a person duly authorized to certify titles under the laws of the state of New York. In the event the title to said property has been duly registered pursuant to the provisions of the real property law for the registration of titles to real property, that fact shall be set forth upon the original map together with the number of the certificate of the title so registered and an index of such abstracts and registrations made to clearly indicate the maps to which they refer and the abstract of title and certificate of title above referred to shall not be required. In the case of a tax title, the fee title for a period of at least twenty years prior to the date of the tax sale under which tax title is claimed must be submitted as a part of the abstract. 9. Every such map, whether intended as an original subdivision or as an alteration of a prior subdivision in such county, shall have endorsed thereon at the time such map is offered to be filed the certificates of the county treasurer and the receiver of taxes of each town and city and the tax collecting officer of each incorporated village within which any part of the tract of land shown on said map or maps is located, or of a title company authorized to transact business in the state of New York stating that all taxes and assessments which are liens prior to the time such original or subsequent map is offered to be filed, whether assessed against the entire tract of land or against any lot or other part of said land, shown on the tax search required to be filed with the county clerk, have been paid. 10. At the time of the filing of such map there shall also be furnished to the county clerk a copy of such map, prepared upon tracing cloth by such process as he shall prescribe, which shall be duly certified by him to be a true copy of the original and which shall be forwarded by him to the board of assessors of the county. 11. The clerk of the county of Nassau upon receiving such maps shall file them by some suitable method in consecutive order and they shall be consecutively numbered in the order of filing and indexed under the initial letters of all substantives in the titles. 12. The fee of the county clerk for receiving and filing each of said separate maps or sheets and indexing the same shall be five dollars, and an additional fee for every block created, which fee shall be the same as the additional fee provided for block indexing by the Nassau county administrative code. 13. Failure to file said map or maps as required by the provisions of this section, shall subject the owner of such lands shown upon such maps, or of unsold lots, plots or units thereon, to a penalty to the people of the state of New York of five hundred dollars for each and every lot, plot or unit thereon subdivided, sold or conveyed by or for such owner prior to the due filing of such map or maps. 14. Whenever at least two years have elapsed since the filing of a map of the subdivision of any tract of land into lots, plots, blocks or sites, with or without opened or proposed roads, the owner of such tract, or of any part thereof having an area equivalent to that of any two or more contiguous lots or an area of not less than one-half acre, may abandon and cancel the subdivision of the property so owned by recording in the office of the county clerk a written certificate of abandonment, duly executed and acknowledged, which shall contain a description of the property to be abandoned, the complete title or name of the map, the filing date and file number thereof, except that no opened or proposed streets, other than those entirely within the bounds of the property to be abandoned, or the area within such bounds of streets which as laid out on said map come to a dead-end within such bounds, shall be abandoned unless each owner of a lot or interest in the subdivision consents to the abandonment thereof by instrument in writing duly executed, acknowledged and recorded with the certificate of abandonment; provided, however, that whenever at least twenty years have elapsed since the filing of said map, the owner of the property to be abandoned may, without such consent, abandon any streets or portions thereof shown on said map and which are within the bounds of the property to be abandoned if such streets or portions thereof are neither opened, nor public highways, nor used by the public, nor necessary for the use of owners, occupants or any other persons having an interest in any part of the subdivision; but nothing herein shall prevent an owner using or a seller of land from conveying part of a lot, plot or site separately or together with an adjoining lot, plot or site, subject to the provisions of local zoning ordinances. Whenever there is on file more than one map of the property to be abandoned, such property must be abandoned in the manner herein provided as to each of such maps. A copy of each certificate of abandonment must be filed with the assessor and/or board of assessors of each town and village wherein any portion of the property to be abandoned is situated, and the endorsement of approval by each such assessor and/or board of assessors must be endorsed on the original of each certificate presented to the county clerk for recording. An abstract of title to the property to be abandoned covering a period of at least twenty years last past, and a certificate of the county treasurer of Nassau county to the effect that there are no unpaid tax liens against such property, must be submitted to the county clerk and be approved by him at the time the certificate of abandonment and cancellation is offered for recording. Said certificates and abstracts shall be filed in the county clerk's office, a suitable index shall be kept of the same, and notice thereof shall be endorsed by the recording officer upon the map therein referred to at the time of recording the certificate of abandonment. Where the endorsement of approval of the town or village assessor above referred to includes a recitation to the effect that the municipality has duly adopted an urban renewal plan pursuant to article fifteen of the general municipal law which plan provides for adequate street access to all properties within and adjacent to the planning area, and further that the property to be abandoned is subject to said plan, and its abandonment is required thereunder, the clerk shall accept and record the certificate of abandonment tendered therefor regardless of the area thereof, and notwithstanding that the property to be abandoned is a portion of an opened or proposed street for which the consent to the abandonment thereof required in this subdivision has not been obtained. Upon the abandonment of subdivided property as herein provided such property shall, for all purposes, be regarded as a single tract of land. No abandonment of lot divisions shall be made under this section for the purpose of reviving or making effective any other subdivision of the same tract of land and no map may be reinstated as it was prior to the filing of any abandonment certificate. The fee of the county clerk for such filing and indexing each certificate and abstract therewith shall be ten dollars and shall be paid by the party presenting them for filing. Provided, however, that the Nassau county board of supervisors shall have full authority to abandon any subdivision of property or any portion thereof which the county of Nassau now owns or may hereafter acquire through the sale of tax liens, by causing to be filed with the county clerk of Nassau county, a certificate of abandonment, duly executed by the said county board, without regard to any of the other foregoing requirements of this section. Nothing contained in this section shall be construed to prevent the filing of a new map and certificate of a subdivision of real property in the manner prescribed herein, after, and in the area of, a subdivision or portion thereof abandoned in accordance with the provisions of this section.