(concurring in part and dissenting in part, with whom Spina and Co win, JJ., join). I concur in the court’s conclusion that Springfield Preservation Trust, Inc., is entitled to a hearing on further remedies. I write separately because I disagree with the court’s conclusion that the exemption contained in § 2.46.030(A) of the Revised Ordinances of the city of Springfield (ordinance) is valid for property owned by the Springfield Library and Museums Association, Inc. (association), and the bishop of the Roman Catholic diocese of Springfield (diocese) at the time the Quadrangle-Mattoon Street Historic District (district) was created in 1972. Rather, I believe that the court should have affirmed the motion judge’s decision to strike the entire exemption as contained in the second sentence of the ordinance.
A historic district must be determined by the legislative branch of a municipality through the creation of a map depicting the boundaries of the district. G. L. c. 40C, § 3. Contrary to the court’s holding today, there is nothing in the statute that states that a municipality can include properties within a map of a historic district yet exempt them through the language of an ordinance, as was done here. I believe that the city exceeded its authority under the Historic District Act, G. L. c. 40C (Act), when it created the exemption without excluding those properties from the requisite map. See Beard v. Salisbury, 378 Mass. 435, 439-440 (1979). See also Greater Boston Real Estate Bd. v. Boston, 397 Mass. 870, 877 (1986) (municipality may have powers not expressly granted in enabling statute, if they are “essential and not merely convenient to the implementation of express powers conferred by statute”).
The ordinance itself cites § 8 (b) of the Act as authority to enact the exemption. I agree with the motion judge that § 8 (b) *427“does not authorize a commission, or municipality, to exempt buildings from commission review and does not authorize the exemption of categories based on ownership and control.”
The association argues that § 10 (z) of the Act offers the actual authorization for the exemption. I disagree. As the court notes, ante at 418-419, § 10 (z) grants a municipality the authority to increase the power or duties of a historic district commission beyond those set forth in the statute. However, because the exemption here excludes property within the district from the power of the Springfield Historical Commission (commission) to review, it is a reduction of the power and duties of the commission, not an increase.
The association and the diocese correctly point out that the Act gives municipalities the discretion whether to establish a historic district and to determine its composition. However, there is no basis to their arguments that the statute grants municipalities broad discretion to create the exemption based on ownership or control. Their argument is based on the selective focus on individual words of the statute, particularly in §§ 3 and 8, which are taken out of context.1 As the motion judge pointed out: “The room for discretion [under the statute] is narrow, the list of exemptions [is] finite.” The judge correctly stated:
“[The Act] grants the [c]ity the power to create historic districts, as well as the power to exempt from the requirements of those districts one or more of a finite set of categories. The power to exempt categories based on ownership or control is not explicitly granted, nor is it necessary to carry out the express powers conferred by the . . . Act. The [c]ity can create, reduce, expand, and otherwise maintain its historic districts without the power to exempt based on ownership or control. . . . [Thus,] the *428failure to infer this particular power from the ones expressly granted would not impair the [c]ity in its exercise of authority, nor would it decrease the effectiveness or longevity of the [c]ity’s preservation efforts.”
See Greater Boston Real Estate Bd. v. Boston, supra at 878 (invaliding ordinance essentially precluding condominium conversion as not essential to carrying out rent control enabling statute). Cf. Flynn v. Cambridge, 383 Mass. 152, 158-159 (1981) (city had implied power to regulate removal of rental units from housing market pursuant to statute allowing rent control).
What is critical here is that property owned by the association and the diocese are included within the map delineating the boundaries of the historic district, as was the property that was demolished. Once a historic district is created, all property within the district is subject to the procedures for alteration contained in the Act, e.g., report, study, notice, and public hearing. G. L. c. 40C, § 3. As the motion judge stated, these procedures show that the Legislature recognized “that any departure from the [Act’s] guiding purpose of ‘preservation and protection’ must be undertaken with care and deliberation. The exemptions [here] . . . permit the [district to be whittled away with almost no deliberation whatsoever (simply by receiving a certificate of non-applicability from the [commission), and with no investigation, report, or public hearing. . . . Permitting the reduction of the [district by such casual, near-ministerial means violates both the letter of § 3 and the purpose of the [Act].”2 It constitutes an impermissible delegation of legislative authority to private interests.
The association and the diocese argue that case law, particularly Opinion of the Justices, 333 Mass. 783 (1955), and Opinion of the Justices, 333 Mass. 773 (1955), supports their position that the statute allows exemptions to be based on ownership or control. These advisory opinions are not apt. They were decided before G. L. c. 40C was enacted, and in each *429instance, the court was asked by the Senate to decide whether the establishment of historic districts on Nantucket and Beacon Hill were a constitutional exercise of State legislative power. Although Opinion of the Justices, 333 Mass. 783 (1955), involved a proposed act that exempted from the Historic Beacon Hill District land owned by the Commonwealth, it does not provide authority in support of the association and the diocese’s argument that this is analogous to the exemption for their property. The Legislature may choose to exempt land owned by the Commonwealth from a historic district the Legislature chooses to create, but that is hardly the same as a city or town, sua sponte, assuming it can exempt property owners located in a historic district from the procedures and requirements of an enabling statute, where there is no explicit statutory authority to do so and such power is not essential to effectuate the statute’s purpose. Greater Boston Real Estate Bd. v. Boston, supra at 877. See Conservation Law Found, of New England, Inc. v. Director of the Div. of Water Pollution Control in the Dep’t of Envtl. Quality Eng’g, 22 Mass. App. Ct. 544, 556 (1986) (Appendix) (listing examples where Legislature “considered [historic] protection mandatory [and] enacted site-specific legislation”).
However, even assuming that the statute does not prohibit municipalities from including properties on an official historic district map and then excluding those same properties through the language of an ordinance, I still conclude that this particular exemption should be struck. Validating the exemption requires the court implicitly to add (or substitute) missing qualifiers to the phrase “however owned or controlled” to the exemption, to reach the conclusion that the city wanted the exemption to the apply to the property the association and diocese owned in 1972. As the court concedes, however, there is no record of what the city council intended by the language of the exemption as written in 1972, and the words “however owned or controlled” are ambiguous. Ante at 422. If the city had wanted the ordinance to apply to those properties owned by the association and diocese in 1972, it easily could have provided language (such as the word “presently”) indicating that intent.
We have declined to do such rewriting of ordinances in the *430past. Greater Boston Real Estate Bd. v. Boston, 428 Mass. 797, 802, 804 (1999) (court will not rewrite offending provision where invalid ordinance provisions too embedded to allow severance from valid provisions). Further, the cases the diocese cites do not show an instance where this court has added qualifiers to an invalid ordinance or exemption. Id. at 804 (redrafting ordinance is task for municipality).
Given the statutory scheme as I read it, the lack of any indication of the city’s intent concerning the exemption, the ambiguity in the language of the exemption itself, and our past case law, I cannot indorse the court’s interpretation of the exemption. Therefore, I respectfully dissent from that part of the court’s opinion.
I likewise reject, as without merit, the association’s argument that the “unfettered ability of the [association] to administer its properties correlates with” the statute’s purpose. The association would have us selectively focus on the words in the first part of G. L. c. 40C, § 2, which states that the statute’s purpose is to “promote the educational, cultural, economic and general welfare of the public,” and ignore the clarifying clause that follows directly thereafter, “through the preservation and protection of the distinctive characteristics of buildings and places.”
The motion judge also noted that the certificate of nonapplicability was issued “despite the fact that only two of the [c]ommission’s seven members voted to issue the certificate.” General Laws c. 40C, § 11, requires a vote of a majority of commission members to issue a certificate.