In this dispute as to who constitutes the legitimate members of the board of trustees of the Vendóme Condominium Trust, the unit owners’ organization (see G. L. c. 183A, §§ 1 & 10)2 of the Vendóme Condominium, *237we are asked to decide whether a provision of the declaration of trust which permits the developer, who retains ownership of only a small percentage of the condominium units, to appoint two of the three members of the board of trustees and the owners of the majority of units to appoint but one trustee is permissible under G. L. c. 183A, § 10. Chapter 183A, § 10, provides:

“(a) Each unit owner shall have the same percentage interest in the corporation, trust or unincorporated association provided for in the master deed for the management and regulation of the condominium as his proportionate interest in the common areas and facilities. Such interest shall not be separated from ownership in the unit to which it appertains and shall be deemed conveyed or encumbered with the unit even though such interest is not expressly mentioned or described in the conveyance or other instrument.”

A District Court judge, sitting by designation in the Superior Court, ruled that the trust provision was enforceable for a “reasonable period of time” and enjoined the defendant trustees, who had been selected by the unit owners to replace the developer’s appointees, from exercising any powers as trustees. We reverse.

The following facts are taken from the judge’s findings, supplemented by the record.

The Vendóme, which is the first mixed use (i.e., residential and commercial) condominium in greater Boston, was owned and created by the Franchi Development Trust, of which Pasquale Franchi is the sole beneficiary. After the Franchi Development Trust defaulted on a loan with the Commonwealth Capital Investment Corporation, the name of the trust was changed to Vendóme Development Trust (“development trust”), the former trustee resigned, and a new trustee designated by the mortgagee was appointed to manage the condominium and market the unsold units. *238That trustee (the plaintiff in this case) then appointed two of the three members of the board of trustees of the unit owners’ organization (who were also designated by the mortgagee). She acted pursuant to section 3.1.3 of the declaration of trust of the unit owners’ organization, which provides that until the development trust owns fewer than twelve units, it has the right to appoint two trustees to the board of the condominium trust and that during that period the total number of trustees will be limited to three.

The dispute with the unit owners over control of the board of trustees of the unit owners’ organization arose after a thirty-eight percent increase in common area charges was approved in late 1977. At a special meeting in May, 1978, the unit owners voted, by approximately a sixty percent majority, to remove the two appointed trustees, expand the board to seven, and appoint five new trustees (the defendants in this case).3 Section 3.3 of the declaration of trust permits the unit owners to remove a trustee by a vote of the owners of fifty-one percent of the beneficial interest; however, it subordinates that right to the right of the development trust to retain the trustees of its choice until fewer than twelve units remain unsold.4

The plaintiff, as trustee of the development trust, then brought this action to enjoin the newly elected trustees from assuming any duties of that office, claiming that her appointees are the legitimate trustees by virtue of sections 3.1.3 and 3.3 of the declaration of trust. The unit owners contend that these provisions are invalid under G. L. *239c. 183A, § 10(a).5 At the time of the trial twenty-three units (all commercial) of a total of 137 units remained unsold.6

The judge ruled that the disputed provisions did not violate G. L. c. 183A, § 10(a), enjoined the defendants from exercising power as trustees, and entered final judgment for the plaintiff. He also ruled that the condominium was still in its marketing phase and that because no time limit was placed on the power granted to the development trust by section 3.1.3, “the power, even if valid, will only be enforced for a reasonable period of time.”

The plaintiff contends that the declaration of trust of the unit owners’ organization meets the requirement of G. L. c. 183A, § 10(a), that each unit owner have “the same percentage interest” in the unit owners’ organization “as his proportionate interest in the common areas and facilities” by providing in Section 4.1 that each unit owner shall have the same beneficial interest in the trust as his/her proportionate interest in the common areas and facilities, and that the statute does not require that unit owners also have the *240same percentage interest in voting as their percentage interest in the common areas.

However, in our opinion the language of the statute itself requires that the unit owners have a proportionate voice in the management of the unit owners’ organization, since it provides that “[e]ach unit owner shall have the same percentage interest in the corporation, trust or unincorporated association . . . for the management and regulation of the condominium as his proportionate interest in the common areas and facilities” (emphasis added). The plaintiff’s interpretation would require us both to ignore the italicized language and to read the limiting word “beneficial” into the statute.7 Moreover, a reading of the statute as a whole (see Universal Mach. Co. v. Alcoholic Beverages Control Commn., 301 Mass. 40, 44 [1938]; 2A Sands, Sutherland Statutory Construction §§ 47.02 & 47.06 [4th ed. 1973]) leaves no doubt that the Legislature intended that the unit owners have a proportionate interest in the management of the organization and not simply a “beneficial” or ownership interest with no voice in management, First, c. 183A, § 1 (inserted by St. 1963, c. 493, § 1), defines the organization of unit owners as “the corporation, trust or association owned by the unit owners and used by them to manage and regulate the condominium” (emphasis added). In addition, c. 183A, § 8 (inserted by St. 1963, c. 493, § 1), provides that “[t]he master deed . . . shall contain the following particulars: . . . (i) The name of the corporation, trust or association which has been formed and through which the unit owners will manage and regulate the condominium . . .” (emphasis added).

Further, the plaintiff’s interpretation would require us to ignore traditional assumptions as to the very definition and concept of a condominium. See, e.g., Berger, Condominium: Shelter on a Statutory Foundation, 63 Colum. L. *241Rev. 989 (1963), which states, at 994, “[T]he condominium relinquishes none of the ownership benefits afforded by stock cooperatives — voice in its management, permanence of tenure, avoidance of profit to the landlord, and tax savings,” and further, at 1004-1005, the declaration “includes ... a statement in fractions of each owner’s share of rights and duties with respect to the common premises. This fraction fixes permanently the unit owner’s pro rata burden of the common expenses and his share in any profit or distribution of capital. It is also the measure of his voice in the management” (emphasis added). Berger adds the comment, at 1006, that “[e]ven if the management of the condominium were turned over to an independent body, the owners would want to reserve the power to countermand its decisions and, if necessary, its control.”

Further confirmation that this interpretation — that § 10 requires that unit owners have a proportionate voting interest in the unit owners’ organization — is correct is provided by c. 183A, § 21(a) (inserted by St. 1972, c. 709, § 3) (see 1A Sands, Sutherland Statutory Construction § 22.34 [4th ed. 1972] [provisions of an amendatory act are to be read together with the provisions of the original act]), which provides that if a condominium does not contain any unit designed for occupancy by only one family or household, or if the total floor area of those units designed for occupancy by one family or household does not exceed ten percent of the total floor area of all units in the condominium, the by-laws may contain, “notwithstanding any provisions of this chapter [,]... (5) [provisions giving a particular unit owner or owners voting rights with respect to election of directors, trustees or members of-the managing board less than, or in excess of, the voting rights which such owner or owners would otherwise have had.” Certainly the assumption of this provision is that the owners are entitled to a certain voting rights interest under other provisions of this chapter; were this not the case, such an amendment would not have been necessary.8

*242To hold, as the plaintiff urges, that § 10 requires only that unit owners have a beneficial and not a voting interest in the unit owners’ organization would be contrary to both the language of the statute and the concept of a condominium. The untenability of this interpretation is illustrated by the fact that it would permit a unit owners’ organization set up in the form of a corporation to be organized so as to give the unit owners only nonvoting stock in the corporation — which clearly would be contrary to the concept of the statute.

In sum, we must conclude that the provision in question here, which gives the development trust, which may own only a small percentage of the units,9 the right to appoint *243two of three trustees and the unit owners, who own the overwhelming majority of the units, the right to appoint but one, does not meet the requirement of § 10 that unit owners have a proportionate interest in the unit owners’ organization for the management and regulation of the condominium.

It is argued, however, that because c. 183A is an enabling act it should be interpreted to permit as much flexibility as possible, and that individuals have a right to enter contracts with provisions different from those set out in the statute. The plaintiff argues in addition that the judge’s ruling that the provision is enforceable for a “reasonable period of time” (which, the plaintiff states, implicitly equates “reasonable period of time” with the marketing phase of the condominium) should stand.

While it is true that c. 183A is an enabling statute and matters not specified should be left to individual parties to be worked out, it is also true that it sets out certain minimum requirements, that is, it enables or authorizes the setting up of a particular type of entity, with certain requirements specified (see, e.g., c. 183A, §§ 5 & 6) and other factors left flexible. The section in question here provides that “[ejach unit owner shall have the same percentage interest in the corporation, trust or unincorporated association . . . for the management and regulation of the condominium as his proportionate interest in the common areas and facilities” (emphasis added). It is accepted statutory construction that “[ujnless the context otherwise indicates the use of the word ‘shall’ . . . indicates a mandatory intent.” 1A Sands, Sutherland Statutory Construction § 25.04 (4th ed. 1972). Thus we conclude that this provision is mandatory and not one of those factors (such as those in § 12, where the word “may” is explicitly used) left to the discretion of the developer.

Since c. 183A, § 10, is mandatory, and since it contains no exception to the requirement set out, we would be reading an exception into the statute to hold, in the absence of statutory language, that the requirement can be waived for *244a “reasonable period of time.” This we cannot do. See Harry Alan Gregg, Jr. Family Foundation, Inc. v. Commissioner of Corps. & Taxn., 330 Mass. 538, 544 (1953); Boylston Water Dist. v. Tahanto Regional Sch. Dist., 353 Mass. 81, 84 (1967).

The judgment is reversed, and a declaratory judgment is to be entered in accordance with this opinion.

So ordered.

(dissenting). I do not quarrel with that part of the majority decision which holds that G. L. c. 183A, § 10(a),1 concerns voting rights of the individual owners in a condominium in the organization created to manage the project. The conclusion that § 10(a) deals with voting rights is logically implicit in the statute’s language. In this respect, § 10(a) operates in congruity with §§ 5(a) and 5(b) of c. 183A,2 to ensure the right of shared participation in the condominium’s common features — a concept which is the essence of the condominium idea.

I part company with my colleagues, however, on the notion that § 10(a) necessarily prohibits the unit owners from entering into valid contracts governing the condominium’s management. General Laws c. 183A was enacted to provide a statutory basis for a form of real estate ownership *245which had a somewhat uncertain status at common law. See Schwartz, Condominium: A Hybrid Castle in the Sky, 44 B.U. L. Rev. 137, 139-143 (1964). The act is fundamentally an enabling statute, like G. L. c. 156B, dealing with business corporations, and G. L. c. 109, pertaining to limited partnerships. Where the statute does not expressly prohibit a practice or is otherwise silent, the parties involved with the condominium are “free to determine their rights with respect to each other [and with respect to the project’s future] by any . . . agreement which does not contravene public policy or run afoul of the common law.” Wasserman v. Wasserman, 7 Mass. App. Ct. 167, 174 (1979). Cf. Johnson v. Keith, 368 Mass. 316, 321-322 (1975); 1 Rohan & Reskin, Condominium Law and Practice § 5.04, at 26-27 (1980). No contention has been made that the trust provisions under study were the product of unfair or deceptive conduct or impermissible overreaching on the developer’s part. Nor is it argued that the trust’s provisions, apart from the perceived conflict with § 10(a), violate any rule of law or policy. The fact that the developer maintained a substantial stake in the condominium’s future is settled by the judge’s findings (based on competent evidence) that “twenty-three . . . commercial units [remain] unsold [and] the . . . [condominium [is] still in the marketing phase.” Furthermore, the existence of the trust and its terms were made known to all who bought condominium units, and the sales and closing documents included acceptance of the management provisions enumerated in the trust. The fact that sales of commercial units have been slower than expected, or that common expenses have increased, will not support rescission of an otherwise valid trust indenture. See Point East Management Corp. v. Point East One Condominium Corp., 282 So.2d 628, 629-630 (Fla. 1973), cert. denied, 415 U.S. 921 (1974). The trust does not divest the other owners to any material or substantial degree of any rights or privileges conferred by c. 183A.

*246In this framework, the majority fail to differentiate between the concepts of ownership and management and incorrectly assumes from the statute’s requirement that the unit owners “shall” have certain percentage interests in the owners’ organization that they must have a precisely corresponding interest in management. Section 10(a) does not so provide. There is evidence in the legislative history that the Legislature was aware of voting rights when it enacted § 10(a),3 but purposely chose to leave the matter to discretionary agreement among the owners and the developer. This made good sense since condominiums differ significantly from one another and it makes especially good sense in this case since the Vendóme is the first mixed use condominium in the Boston area. Thus the majority has written a new provision into § 10(a) which effectively precludes condominium owners from contracting for the contingencies that affect the condominium’s management. I suggest that *247this result, if intended by the Legislature as a matter of policy, would have been clearly expressed in § 10(a).

Finally, I am concerned about the effect of the holding on existing condominiums. General Laws c. 183A is a primitive, first generation condominium statute4 primarily designed to govern residential condominiums. Its draftsmen probably did not anticipate phased condominiums, mixed use condominiums, commercial condominiums, or any of the other mutations which creative real estate lawyers have contrived. Lawyers, mortgagees, lienholders, developers, unit owners and others involved with second generation condominiums have considered c. 183A as affording a measure of flexibility with respect to the condominium’s creation and development and have tailored sophisticated condominium documents to work out the equitable interests of the parties on a host of issues including management. I suspect that the validity of many of these agreements will now be thrown into question and that many people who relied on the statute will soon find their peace and confidence disrupted by unwarranted litigation.

I would affirm the judgment entered in the Superior Court,5 and apply § 10(a) to determine voting interests only in those cases where the condominium’s documents are silent on the question of control.