This case concerns the use of land and a building at 12 Morris Street in Lynn (premises), as a group residence for fifteen elderly, mentally ill persons. The premises are located in a business zone which does not allow a group residence as of right. The Lynn city council (council) granted a special permit under § 18 of the Lynn zoning ordinance (ordinance) authorizing the premises to be used as a group residence, and the Lynn zoning board of appeals (board) rejected an appeal by the plaintiffs which sought to revoke the building permit issued by the building commissioner for alterations to the premises. These decisions were challenged by the plaintiffs in separate actions in the Superior Court (special permit), and Land Court (building permit). Judgments were entered in those actions upholding the respective decisions of the council and the board. The Appeals Court affirmed both judgments, concluding that: (1) *774the proposed use of the premises was lawful because of the special permit and the fact that the group residence constituted a use for an educational purpose protected by G. L. c. 40A, § 3, (1990 ed.); (2) that statute conferred on the Lynn zoning officials discretion not to apply any provisions of the ordinance concerning bulk, dimensional and parking requirements that might otherwise pertain to the premises; and (3) adequate findings had been made under G. L. c. 40A, and the ordinance, to support the various decisions under review. See 32 Mass. App. Ct. 152 (1992). We granted further appellate review only to examine the issues connected to the second point. We conclude that the bulk and dimensional requirements cannot be applied to the premises. We also conclude that the matter of off-street parking should be reconsidered by the board.
The premises include a three-story, twenty-seven room building on a 3,947 square foot parcel of land situated in a business zone which allows residential uses by special permit. Next to the premises is a lot containing a house which is used as a single family residence. The premises had been used as a convent housing nuns. When the convent ceased operations, the premises were acquired by the defendants Thomas B. Goff, Jr., and James P. Lyons (owners), who proposed to use the premises for the group residence previously described. The premises would be leased to the Greater Lynn Senior Services, a nonprofit corporation which, together with the Department of Mental Health, would provide staffing and support services to the residents.
With this use in mind, the owners applied to the council and received a special permit to operate a group residence ift a business zone. The permit was subject to the conditions noted below.4 The plaintiffs commenced an action in the Superior Court contending that the council had exceeded its authority in granting the special permit and asking that it be *775annulled. After trial, a judge of the Superior Court upheld the grant of the special permit and also concluded that, because the premises were to be used for an educational purpose, they were “exclude [d] from local control” under G. L. c. 40A, § 3, second par.
Subsequently, the owners obtained a building permit from the Lynn building commissioner to make alterations to the premises. The plaintiffs next sought to have the commissioner revoke the building permit, claiming, among other things, that the premises were not in compliance with certain general bulk, dimensional and parking requirements of the ordinance. The commissioner refused relief, and his decision was upheld by the board. The plaintiffs thereafter filed a complaint in the Land Court seeking to have the board’s decision annulled. A record was prepared, and cross-motions for summary judgment were filed. A judge of the Land Court determined that there were no material issues of fact in dispute and allowed the motions of the board and the owners for summary judgment. Judgment entered dismissing the plaintiffs’ appeal of the board’s decision. As has been indicated, the judgments of the Superior and Land Courts were affirmed by the Appeals Court.
1. The special permit granted by the city council did not have the effect of relieving the owners from compliance with the general bulk, dimensional and parking requirements of the ordinance. It appears that the special permit may have been sought, and obtained, before it occurred to anyone that the group residence might constitute a use for an educational purpose protected under G. L. c. 40A, § 3, second par.5 The permit was granted pursuant to the provisions in G. L. c. 40A, § 9, and § 18 of the ordinance, to authorize a use which required special permission from the council before it could be maintained in a business zone. The special permit could not effectively resolve compliance with other require*776ments of the ordinance. See SMI Investors (Delaware), Inc. v. Planning Bd. of Tisbury, 18 Mass. App. Ct. 408, 413-414 (1984).
2. General Laws c. 40A, § 3, second par., as inserted by St. 1975, c. 808, § 3 (generally referred to as the Dover Amendment), provides, in part, as follows:
“No zoning ordinance or by-law shall . . . prohibit, regulate or restrict the use of land or structures for religious purposes or for educational purposes on land owned or leased by the commonwealth or any of its agencies, subdivisions or bodies politic . . . provided, however, that such land or structures may be subject to reasonable regulations concerning the bulk and height of structures and determining yard sizes, lot area, setbacks, open space, parking and building coverage requirements.”
The Appeals Court’s affirmance of the Superior Court judgment, see 32 Mass. App. Ct. at 153-155, and our limitation of the issues to be considered by this court, establish that the use of the premises as a group residence for elderly, mentally ill persons is a protected use for an educational purpose within the meaning of § 3 above. The Superior Court did not address the question of the application of any of the ordinance’s general bulk, dimensional and parking requirements to the premises. That question was taken up in the Land Court. In the order granting the motions for summary judgment of the board and the owners, the Land Court judge noted that the Lynn zoning officials (the building commissioner and board) had not “attempted to apply the general [bulk, dimensional, and parking] provisions of the ordinance to the site.” The judge reviewed the case law interpreting the Dover Amendment, and, based on the cases and the language of the statute, stated that “[i]t is clear from [§ 3] that . . . application [of general regulations] is permissive at best and suspect at worst.” The judge then ruled that “the site is free from the provisions of the [zjoning [ordinance.” The judge *777appears to have reasoned that the zoning officials could lawfully grant a building permit to further the use of the premises for an educational purpose, despite the fact that the premises did not comply with general bulk, dimensional, and parking requirements, where application of those requirements would prevent the use and impermissibly nullify the protection granted to it by G. L. c. 40A, § 3, second par. We conclude that the judge’s decision was correct with respect to the bulk and dimensional requirements of the ordinance,6 but *778that the record lacks sufficient information to decide the applicability of the parking requirements.
The Appeals Court, in upholding the decision of the Land Court, reasoned that the word “may” in the proviso to G. L. c. 40A, § 3, second par., conferred absolute discretion on the zoning officials to disregard general requirements of the ordinance that would normally apply to the premises. 32 Mass. App. Ct. at 156-157. This conclusion is wrong because the law does not go this far. Local zoning requirements are meant to be applied uniformly, Trustees of Tufts College v. Medford, ante 753 (1993), and consequently, local officials may not grant blanket exemptions from the requirements to protected uses. The officials may, however, on an appropriate showing, decide that facially reasonable zoning requirements concerning bulk and dimension cannot be applied to an educational use occupying a particular site because application of the requirements would improperly nullify the protection granted to the use, or because compliance with the requirements would significantly impede an educational use, in either instance without appreciably advancing municipal goals embodied in the local zoning law.7 Id. at 757-761. This, in substance, was the basis of the decision by the Lynn zoning officials when they granted the building permit requested by the owners.
If a decision like the one made here is challenged by abut-tors or neighbors, in the position of the plaintiffs, a judge must decide whether the action taken by the local zoning officials was justified under G. L. c. 40A, § 3, second par. This *779will often be a fact-based inquiry. Trustees of Tufts College v. Medford, supra at 759-760. In this case, however, the facts with respect to the bulk and dimensional requirements are undisputed. In connection with their motion for summary judgment in the Land Court, the plaintiffs filed an affidavit simply alleging that the premises do not comply with the various requirements of the ordinance.8 It is clear from the plaintiffs’ affidavit, and from the record, that the premises cannot be made to conform to any applicable bulk or dimensional requirements because the building occupies most of a small (3,947 square foot) lot. This conclusion makes it evident that, apart from the difficulty of analogizing the proposed use to any use regulated in the ordinance, see note 8 supra, the application of the bulk and dimensional requirements referred to by the plaintiffs, in the manner urged by them, would effectively deny the use of the premises for any conceivable educational purpose with no valid goal of municipal zoning regulation being served thereby. Further, contrary to the plaintiffs’ position, the owners cannot be compelled to seek a variance in order to have their educational use. See note 7 supra. We therefore agree with the Land Court judge that the case presents a situation where local zoning officials correctly decided that the general bulk and dimensional requirements of the ordinance could not be properly applied because their application would contradict the protection granted by G. L. c. 40A, § 3, second par., to an educational use.9
*780The situation may be different with respect to the ordinance’s off-street parking requirements. The ordinance appears to require that the premises have a minimum number of off-street parking spaces that conform to certain design standards. The record does not disclose whether the requirements can be met. (In connection with this aspect of the case, it will be recalled that the council required in the special use permit that the owners develop an off-street parking plan. See note 4, supra.) In the materials before the Land Court judge, Lynn zoning officials have taken no clear position regarding the off-street parking issue. Adequate off-street parking, of course, can be a valid concern to municipalities, and it is a matter of regulation authorized by the proviso to § 3, second par. See Radcliffe College v. Cambridge, 350 Mass. 613, 617-618 (1966). We conclude that the record is insufficient to determine whether compliance with any applicable off-street parking requirements can be demanded. Accordingly, the question of off-street parking must be reexamined in light of the principles expressed in Trustees of Tufts College v. Medford, supra, and this opinion.
3. Disposition. The judgment in the Superior Court is affirmed. The judgment in the Land Court is vacated. The rulings in the Land Court that the bulk and dimensional requirements of the ordinance cannot be applied to the premises are affirmed. The case is to be remanded by the Land Court to the board which is to consider the applicability to the premises of any off-street parking requirements in *781the ordinance. The Land Court is to retain jurisdiction after that matter is considered by the board for the entry of a new judgment consistent with this opinion.
So ordered.
The conditions were (1) that the residence be for Lynn residents only, (2) that forty per cent of the fifteen units be reserved for West Lynn residents, (3) that the city council’s committee on housing review the property in one year, and (4) that an off-street parking plan be developed.
As a general rule, a municipality cannot condition the use of property for an educational purpose on the grant of a special permit. See Trustees of Tufts College v. Medford, ante at 753, 755 n.3 (1993); The Bible Speaks v. Board of Appeals of Lenox, 8 Mass. App. Ct. 19, 32-34 (1979).
The problem in this case arises principally from the fact that the premises are nonconforming. Because a large twenty-seven room structure occupies a small (3,947 square foot) lot, the premises cannot be made to comply with bulk and dimensional requirements. This fact holds true no matter what use is made of the existing structure. In view of the nonconforming nature of the premises, the problems in the case might have been more easily resolved under G. L. c. 40A, § 6 (1990 ed.). That statute excuses an unaltered nonconforming structure (a structure in existence prior to enactment of a local zoning law) from compliance with the law. The owners sought a building permit to make certain changes to the premises, including changing doors and windows, enlarging closets and adding an elevator. No inquiry was made as to whether these changes were sufficient to take the premises outside of the protection granted by § 6 to a nonconforming structure. See Crawford v. Building Inspector of Barnstable, 356 Mass. 174, 176-178 (1969) (enclosing outside porch was minor alteration that could be made as of right to nonconforming structure; decided under prior G. L. c. 40A, § 5).
Section 6 also allows changes, extensions, and structural alterations to a prior nonconforming structure or use in certain defined circumstances with the approval of local zoning officials. Local officials could not deny the owners the right to use the premises for educational purposes. If the proposed alterations could not be made as of right under § 6, the owners could nonetheless seek the requisite determination by zoning officials that the proposed alterations to the structure should be permitted because the result would not be substantially more detrimental to the neighborhood than the existing nonconforming structure. See Willard v. Board of Appeals of Orleans, 25 Mass. App. Ct. 15, 20-21 (1987).
We understand Justice O’Connor to maintain in his dissent, post, that the owners must obtain the building permit necessary for their plans by proceeding under G. L. c. 40A, § 6, because, in his view, G. L. c. 40A, § 3, cannot be read to exempt the structure from the relevant dimensional and parking requirements. We disagree with this contention. This case was decided in the Land Court solely on the basis of G. L. c. 40A, § 3, second par., without reference to the possible application of § 6, and the record is not sufficient to permit resolution of the case under § 6. We conclude that the owners are entitled to a measure of relief based on § 3. There is there*778fore no reason to require them to recommence proceedings under § 6, and to suffer the delays and costs that would be associated with such a course.
The plaintiffs have suggested that the owners’ sole recourse in this case is to seek a variance for use of the building. Variances may .only be granted in limited circumstances specified by G. L. c. 40A, § 10 (1990 ed.), having to do with the soil conditions, shape or topography of the locus. See Guiragossian v. Board of Appeals of Watertown, 21 Mass. App. Ct. 111, 115 (1985). In Trustees of Tufts College v. Medford, supra at 760, we rejected a contention that an educational use claiming an inability to comply with a local zoning law must obtain a variance to proceed with its proposed project.
“In taking this position, the plaintiffs have some difficulty in classifying the group residence for the purpose of determining which requirements in the ordinance might apply. The plaintiffs, at various points, have referred to the requirements concerning apartment houses, elderly housing projects, hospitals, nursing homes and convalescent homes as possibly applicable to the premises. The group residence cannot be classified as any of thesfe.
Our decision does not imply that any nonconforming structure for which an educational use is proposed will necessarily be free from the bulk and dimensional requirements of a local zoning law. “[T]he question of the reasonableness of a local zoning requirement, as applied to a proposed educational use, will depend on the particular facts of each case . . . [and] an educational [use challenging such requirements] will bear the burden of proving that the local requirements are unreasonable as applied to its pro*780posed project.” Trustees of Tufts College v. Medford, supra at 759. Local zoning officials properly could refuse a building permit for alterations to a nonconforming structure where, for example, the failure to meet local zoning requirements raised safety concerns.
One other observation, in response to Justice O’Connor’s dissent, is appropriate. It is unlikely that an educational user proposing to build a new structure on a single small lot could argue successfully that dimensional, coverage and parking requirements would be unreasonable as applied to the property. As Justice Wilkins suggests, see post at 782, in these circumstances, local officials might be warranted in requiring that an educational user seek an alternative site.