This is a bill in equity by way of an appeal under G. L. c. 40A, § 21, by the trustees of the Lakeridge Realty Trust from a decision of the board of appeals of the town of Ashland (board) sustaining the building inspector’s denial of a building permit. The board appealed from a final decree annulling its action and directing the issuance of the building permit. The judge filed “Findings, Rulings and Order for Decree” which he subsequently adopted as a report of material facts. The evidence is reported.
*661The specific lot in question was at one time one of nine lots comprising a tract of land owned by one Farese. Four of these lots were front lots not requiring the approval of the planning board for subdivision and were sold to a developer who constructed single family dwellings on them.
On June 6, 1962, a prehminary plan for the subdivision of the remaining five lots was submitted to the planning board and notice of its submission was given to the town clerk. A definitive plan was approved on December 6,1962. On both of these dates the controlling provision of the zoning by-law of Ashland read as follows: “Section II. Use Regulations. 1. In residential and agricultural districts. Buildings, structures, and premises may be used for any residential . . . purpose. . . .” The lots shown on the definitive plan were within a residential district. At the annual town meeting on March 11, 1964, the zoning by-law was amended to create Residential “A" and Residential “B” districts. In Residential “A” districts the use of buildings, structures and premises was limited to “any single residential . . . purpose. . . .” The lots shown on the definitive plan are within a Residential “A” district.
On March 7, 1966, the plaintiffs acquired title to the five lots from one Quinn who had purchased them from Farese the previous year. On July 20, 1966, one of the plaintiffs filed with the building inspector an application for a building permit for an apartment building on one of the lots shown on the definitive plan. The application was disapproved because of the “Residential area 'A’ [zoning]." The plaintiffs appealed to the board which held a public hearing and filed a decision upholding the action of the building inspector. The trial judge ruled that, in accordance with the provisions of G. L. c. 40A, § 7A, the action of the board was in excess of its authority and directed the building inspector to issue the requested building permit.
General Laws c. 40A, § 7A, as amended through St. 1961, c. 435, § 2, stated in pertinent part that “[w]hen a preliminary plan . . . has been submitted to a planning board, and written notice of the submission of such plan has been *662given to the city or town clerk, . . . and, if.... ...[the] definitive. plan [evolved from the preliminary plan], becomes approved, . . . [the] provisions of the ordinance or bydaiw in effect at the time of the submission of the first submitted plan shall govern the land shown on such approved definitive plan for a period of five years from the. date of such approval notwithstanding any other provision of law” (emphasis added).
The board concedes that § 7A “lends much force”: to the contention of the plaintiffs that they are .entitled to build any structure permitted by the zoning by-law. in effect in 1962. However, they contend that.:the scope of §. 7A‘.is limited to the permissible use contemplated by the planning board at the time that the plan was approved/ The board points.to the finding of the trial judge that “the Planning Board was of the opinion that it was going to bé developed for single family dwelling houses.”: What the board is. in essence urging is that the planning board’s.opinion constij* tutes an implied restriction on the use ‘of. the subdivision. Such a restriction, however, is expressly prohibited by. the Subdivision Control Law. General Laws c. 41, .§ 81Q, inserted by St. 1953, c. 674, § 7, states in .pertinent' part that “[e]xcept in so far as it may require'compliance with the requirements of existing zoning ordinances or by-laws, no rule or regulation [of the planning board], shall relate -to the size, shape, width, frontage or use of lots' within a subdivision, or to the buildings which may be .constructed thereon.” The planning board could have adopted-a regulation that “not more than one building designed or available for use for dwelling purposes shall be erected or placed or converted to use as such on any lot in a subdivision, or elsewhere in the city or town, without, the consent of the planning board.” G. L. c. 41, § 81Q.1 If the. ways w.ere “not otherwise deemed adequate,” the planning board.could have expressly limited within a particular subdivision-:the *663“lots upon which buildings . . . [might have been] erected and the number of buildings that . . . [might have been] erected on particular lots.” G. L. c. 41, § 81R.2 See Ellen M. Gifford Sheltering Home Corp. v. Board of Appeals of Wayland, 349 Mass. 292. But the planning board could not have expressly limited the use of a subdivision lot to a single-family dwelling where the applicable zoning by-law permitted a multi-family dwelling. In any event, the planning board’s opinion as to the contemplated use of a subdivision lot at the time of its approval of the subdivision plan could not do so. “There is no uncertainty or ambiguity in § 7A. The statute gives a period of three [now seven3] years within which the owner of the land shown on the approved plan may proceed under the provisions of the zoning by-law as in force prior to their amendment.” Smith v. Board of Appeals of Needham, 339 Mass. 399, 402. See Ward & Johnson, Inc. v. Planning Bd. of Whitman, 343 Mass. 466.
The board’s argument that the purposes of the Subdivision Control Law will be completely defeated by the unqualified application of G. L. c. 40A, § 7A, is without merit. While the Legislature clearly intended the furtherance of the purposes outlined in G. L. c. 41, § 81M, we think that the Legislature also intended to protect the developer. In addition to § 7A, G. L. c. 41, § 81Q, as amended through St. 1960, c. 196, protects the developer from a change in the rules and regulations established under that section while the subdivision plan is before the planning board for approval.
Decree affirmed.