The Gardner-Athol Area Mental Health Assocation, Inc. (GAAMHA), supported by the Department of Mental Health (department), argues that, because GAAMHA is a “nonprofit educational coiporation” and because its proposed use of premises in Gardner as a residential care facility would be a use of the premises for “educational purposes,” the Gardner zoning ordinance may not lawfully forbid GAAMHA’s proposed use of premises for a residential care facility for four adults with mental disabilities. GAAMHA relies on the provision in G. L. c. 40A, § 3 (1986 ed.), which denies to a municipality the right to restrict by zoning “the use of land or structures ... for educational purposes... by a nonprofit educational corporation.”
A District Court judge, deciding GAAMHA’s appeal (G. L. c. 40A, § 17) from a decision of the Gardner board of appeals (board), agreed that GAAMHA’s proposed use was for educational purposes but that GAAMHA was not a “nonprofit educational corporation” within the meaning of G. L. c. 40A, § 3. We agree that the proposed use would be for educational purposes, an issue which needs no further discussion. See Fitchburg Hous. Auth. v. Board of Zoning Appeals of Fitchburg, 380 Mass. 869, 874 (1980); Commissioner of Code Inspection of Worcester v. Worcester Dynamy, Inc., 11 Mass. App. Ct. 97, 99-100 (1980). Cf. Whitinsville Retirement Soc’y v. North-bridge, 394 Mass. 757, 760 (1985) (primary purpose of a proposed nursing home not educational). We disagree, however, with the judge’s conclusion that GAAMHA is not a nonprofit educational corporation. Because GAAMHA is a nonprofit educational corporation, the Gardner zoning ordinance may not lawfully restrict GAAMHA’s proposed use of the premises.3 *14We summarize relevant facts found by the judge. GAAMHA is a nonprofit corporation organized pursuant to G. L. c. 180. Its articles of organization state its purposes as follows: “To cooperate with the State and National Associations for Mental Health and other Mental Health Associations as well as State and other governmental agencies to promote a program of mental health education; to provide means and facilities to aid in the prevention, care and treatment of mental health disorders; to aid in the restoration of mental health and to aid in the rehabilitation of the mentally handicapped, and to do all things necessary and incidental to the carrying out of these purposes.” GAAMHA operates programs for the mentally ill and mentally retarded, in addition to providing vocational training and alcohol dependence programs. GAAMHA operates an outpatient clinic and recovery home for alcoholics.
In October, 1985, GAAMHA leased a single family dwelling on Edgell Street in Gardner for use as a residential care facility for four adults with mental disabilities, pursuant to a program funded by the Commonwealth. The residents would be taught daily living, as well as vocational skills, with the goal of preparing them for more independent living. Shortly before the lease was executed, an Edgell Street resident wrote to the building inspector questioning the proposed use of the property. The building inspector answered that the proposed use would be exempt from the application of the Gardner zoning ordinance by virtue of G. L. c. 40A, § 3. Numerous residents of the area appealed the building inspector’s decision to the board. The board received advice from the city solicitor that he had advised the building inspector that the city could not prohibit the proposed use. The board nevertheless reversed the building inspector’s ruling in a decision that did not state the board’s reasons for its decision.4
On GAAMHA’s appeal the department intervened, and the judge, concluding that education appeared to play a subordinate *15role in GAAMHA’s activities and that GAAMHA was not a nonprofit educational corporation, affirmed the board’s decision. GAAMHA and the department appealed, and we allowed their applications for direct appellate review.
GAAMHA is a nonprofit corporation. The issue is whether it is a nonprofit educational corporation. GAAMHA’s corporate purposes, set forth above, surely include educational purposes. Cooperation with private associations and governmental agencies “to promote a program of mental health education,” “to aid in the restoration of mental health and to aid in the rehabilitation of the mentally handicapped” are clearly educational purposes. Rehabilitation surely falls within the meaning of education. See Harbor Schools, Inc. v. Board of Appeals of Haverhill, 5 Mass. App. Ct. 600, 604-605 (1977).
There is nothing in G. L. c. 40A, § 3, as the board argues, that requires that education be the dominant purpose or primary activity of a nonprofit corporation in order that it may qualify as a nonprofit educational corporation under § 3. We have no authority to rewrite the statute to insert such a requirement.5 Acceptance of the concept that the dominant or principal activity of such a corporation must be educational would require the investigation and assessment of detailed facts not readily available to one administering local zoning regulations and presumably that duty would be a continuing one.6 The proper test in deciding whether a nonprofit corporation is an educa*16tional one is whether its articles of organization permit it to engage in educational activities, a question easily answered by a review of documents filed with the State.
There is no reason to find uncertainty in § 3, thus arguably justifying adding a requirement that the corporation’s activities be primarily in education. See Worcester County Christian Communications, Inc. v. Board of Appeals of Spencer, 22 Mass. App. Ct. 83, 87 (1986) (“all that is required is that the plaintiff be a nonprofit corporation intending to use its land or structures for religious or educational purposes”). The word educational in the phrase “nonprofit educational corporation” is not made superfluous by our construction of the statute. Not every word in a statute need carry a heavy load. It is enough to say that “educational” in the phrase “nonprofit educational corporation” means that the proposed educational activities must be within the corporate purposes of the nonprofit corporation. That this states the obvious — no corporation should act ultra vires — does not deprive the word “educational” of any meaning in § 3 as written. Thus, there is no warrant for injecting the word “primarily” in § 3 for the asserted purpose of giving meaning to the word “educational” which it could not otherwise have.
The judgment of the District Court is vacated. Judgment shall be entered reversing the decision of the board of appeals and affirming the determination of the building inspector. First, however, the issue whether GAAMHA and the department are entitled to costs against the board must be decided. See G. L. c. 40A, § 17, fourth par. (1986 ed.) (no costs are allowed against the board “unless it shall appear to the court that the board . ... in making the decision appealed from acted with gross negligence, in bad faith or with malice”). The judge deferred this question and, when he decided the case in favor of the board on the merits, he concluded that he did not have to decide whether to award costs against the board.
So ordered.
Such a use would be lawful under the zoning ordinance if the board were to grant a special permit. GAAMHA asserts that it has a right to use the premises as proposed and that use cannot properly be regulated by the zoning ordinance.
The board’s decision recited certain views apparently expressed by its chairman, none of which concerned the issue whether GAAMHA was a nonprofit educational corporation.
There is no legislative history to support such a view. Indeed, at the time § 3 took its present form in 1975 (see St. 1975, c. 808, § 3), the existence of the Commonwealth’s policy of continuing deinstitutionalization of mental health patients suggests that there was no legislative intention to increase the right of municipalities to restrict residential facilities for mentally handicapped people. Surely under prior law (see G. L. c. 40A, § 2, as amended through St. 1959, c. 607, § 1) the use proposed in this case could not have been regulated by local zoning provisions. See Fitchburg Hous. Auth. v. Board of Zoning Appeals of Fitchburg, 380 Mass. 869 (1980).
If a nonprofit corporation once primarily in education (and protected by § 3) should increase its other authorized nonprofit activities so that they became primary, on the board’s theory the corporation would lose its § 3 protection.