Court Opinion

ID: 7845193
Source: CourtListenerOpinion
Date Created: 2022-09-08 17:09:11.068297+00
Date Added: 2024-06-11T16:21:13.466070
License: Public Domain

Opinion

PALMER, J.
This appeal requires us to determine whether hospital employees who perform plumbing work for the hospital are exempt from the licensure requirements of chapter 393 of the General Statutes, § 20-330 et seq.2 We conclude that they are not exempt.
The following facts and procedural history are undisputed. On October 7,1994, the defendant plumbing and piping work board (board)3 issued complaints against the plaintiffs, Hartford Hospital (hospital) and Herve Gelinas, Charles Rowe and Arnrit Kalicharen, three of the hospital’s employees.4 Specifically, the board *711alleged that the hospital had violated General Statutes §§ 20-334, 20-337 and 20-3415 because certain of its *712employees had performed plumbing and piping work6 on the hospital premises without a certificate, license *713or registration to do so. The board further alleged that Gelinas, a foreman, had violated the licensure requirements of chapter 393 by causing plumbing work to be performed by hospital employees who were not licensed or registered to do such work.7 With respect to Rowe and Kalicharen, the board claimed that they had violated statutory licensure provisions by performing plumbing work at the hospital without a license.
In November, 1994, the plaintiffs sought a declaratory ruling8 that the statutory licensure requirements are inapplicable to them because the work performed by Rowe and Kalicharen was primarily maintenance work and not plumbing installation work. Alternatively, the plaintiffs claimed that they are exempt from the requirements of chapter 393 because the hospital is an “industrial firm” within the meaning of § 20-340 (6).9 After a *714hearing, the board issued a declaratory ruling in which it concluded that the work performed by Rowe and Kalicharen constituted plumbing and piping work under § 20-330 (3) and, further, that § 20-340 (6) does not exempt the hospital’s employees from the statutory licensure requirements.
The plaintiffs appealed from the declaratory ruling of the board to the Superior Court pursuant to General Statutes § 4-183, claiming that § 20-340 (6) exempts employees of the hospital from the licensure requirements of chapter 393.10 The trial court agreed with the plaintiffs that the hospital is an “industrial firm” within the meaning of § 20-340 (6) and, consequently, sustained the plaintiffs’ appeal. The defendants appealed *715from the judgment of the trial court to the Appellate Court, and we transferred the appeal to this court pursuant to Practice Book § 4023 and General Statutes § 51-199 (c). On appeal, the defendants renew their argument that the hospital is not an “industrial firm” under § 20-340 (6) and, therefore, is not exempt from the licensure requirements of chapter 393. We agree with the defendants.
“[B]ecause our resolution of the [defendants’] claim requires the application of a statutory provision, namely, [§ 20-340 (6)], to a specific factual scenario, we are . . . guided by well established tenets of statutory interpretation. It is fundamental that statutory construction requires us to ascertain the intent of the legislature and to construe the statute in a manner that effectuates that intent. . . In seeking to discern that intent, we look to the words of the statute itself, to the legislative history and circumstances surrounding its enactment, to the legislative policy it was designed to implement, and to its relationship to existing legislation and common law principles governing the same general subject matter.” (Citations omitted; internal quotation marks omitted.) Cannata v. Dept. of Environmental Protection, 239 Conn. 124, 140-41, 680 A.2d 1329 (1996). “Furthermore, when a state agency’s determination of a question of law has not previously been subject to judicial scrutiny, as in this case, the agency’s determination is not entitled to special deference.” Angelsea Productions, Inc. v. Commission on Human Rights & Opportunities, 236 Conn. 681, 688, 674 A.2d 1300 (1996); see Duni v. United Technologies Corp., 239 Conn. 19, 25, 682 A.2d 99 (1996). Finally, exemptions to statutes are to be strictly construed; Cannata v. Dept, of Environmental Protection, supra, 141; and “those who claim the benefit of an exception under a statute have the burden of proving that they come within the limited *716class for whose benefit it was established.” Conservation Commission v. Price, 193 Conn. 414, 424, 479 A.2d 187 (1984); Aaron v. Conservation Commission, 183 Conn. 532, 549, 441 A.2d 30 (1981). With these principles in mind, we turn to the defendants’ claim.
Section 20-334 provides that individuals performing certain kinds of work, including plumbing and piping work, must be licensed. Since the enactment of the statutory licensure requirements in 1965,11 the legislature has created eleven exemptions to the licensing mandate of § 20-334, including the exemption under § 20-340 (6) for any person employed by an “industrial firm” whose main duties concern, inter aha, plumbing and piping work.12 The plaintiffs’ sole claim of exemption from the requirements of § 20-334 is that the hospital is an “industrial firm” under § 20-340 (6). Specifically, the plaintiffs, urging a broad construction of the term “industrial firm,” maintain that that term encompasses all commercial enterprises engaged in any industry, including the health industry. The defendants, on the other hand, contend that the term applies only to business entities involved in manufacturing activities and, consequently, that the hospital, because it is not involved in such activities, does not fall within the exemption.
Where, as here, a statute does not define a term, “we refer to [its] commonly approved usage for guidance in our determination.” Williams v. Best Cleaners, Inc., *717237 Conn. 490, 500, 677 A.2d 1356 (1996); see Krafick v. Krafick, 234 Conn. 783, 794, 663 A.2d 365 (1995). The term “industrial firm” is not defined in the dictionary; see, e.g., Webster’s Third New International Dictionary; and the dictionary definitions of “industrial” and “firm” provide little guidance as to whether the term “industrial firm” connotes only an enterprise that is involved in manufacturing activities, as the defendants claim, or one that is engaged in any form of business or commercial activity, as the plaintiffs contend.13 Moreover, we have not had previous occasion to define the precise term “industrial firm,” in this or any other context. Cf. United Illuminating Co. v. Groppo, 220 Conn. 749, 754-55, 601 A.2d 1005 (1992) (discussing term “industrial plant” as defined in regulations relating to taxing statutes); Roan v. Connecticut Industrial Building Commission, 150 Conn. 333, 335-36, 189 A.2d 399 (1963) (discussing term “industrial plant” as defined under statute, since repealed, creating industrial building commission).
As the plaintiffs conceded at oral argument, however, the term “industrial firm” is not one which, in common parlance, ordinarily would be deemed to include a hospital. Moreover, the plaintiffs further acknowledge that, under the expansive definition of the term they espouse, *718virtually any business or commercial enterprise would qualify as an “industrial firm,” including, for example, insurance companies, banks, private schools and colleges, hotels and restaurants, retail stores, apartment complexes, and the like. We do not think that the commonly approved usage of the term “industrial firm” includes these and other such business enterprises. By contrast, the term “industrial firm” more readily brings to mind commercial entities engaged in manufacturing activities.
Furthermore, several well established tenets of statutory construction provide persuasive support for the defendants’ claim regarding the intended scope of the exemption created under § 20-340 (6). First, under the interpretation of the term “industrial firm” advanced by the plaintiffs, the word “industrial” has little, if any, significance because virtually any “firm” — that is, any “business unit or enterprise”14 — would qualify for the exemption created under § 20-340 (6). In addition, under the plaintiffs’ interpretation of “industrial firm,” the exemption created by § 20-340 (9) for “employees of stage and theatrical companies” and the exemption under § 20-340 (10) for “employees of carnivals, circuses or similar transient amusement shows”15 would be unnecessary because those persons already would be exempt from the statutory licensure requirements by operation of § 20-340 (6). “It is a basic tenet of statutory construction that the legislature did not intend to enact meaningless provisions. . . . [I]n construing statutes, we presume1 that there is a purpose behind every sentence, clause, or phrase used in an act and that no part of a statute is superfluous.” (Citations omitted; internal quotation marks omitted.) Castagno v. Wholean, 239 Conn. 336, 346, 684 A.2d 1181 (1996); Fleming v. Garnett, 231 Conn. 77, 90-91, 646 A.2d 1308 (1994). In contrast to the plaintiffs’ interpretation of § 20-340 (6), the *719statutory construction advanced by the defendants gives full effect both to the word “industrial” and to each of the ten other exemptions created by the legislature under § 20-340.
Second, the plaintiffs also concede that under their construction of the term “industrial firm,” only that class of persons performing plumbing services for the general public is likely to fall outside the scope of the exemption created by § 20-340 (6). If the legislature had intended to limit the statutory licensure requirement in such a manner, it easily could have done so without creating the numerous exemptions set forth under § 20-340.16 See, e.g., LoPresto v. State Employees Retirement Commission, 234 Conn. 424, 435, 451-52, 662 A.2d 738 (1995). The fact that the legislature eschewed that approach and, instead, crafted eleven specific exemptions to the licensure requirement suggests that it did not intend such a sweeping application of § 20-340 (6).
Finally, a primary purpose of the licensure requirement, in addition to establishing a uniform, statewide *720system of licensing, is to protect the public health and safety. See, e.g., 11 S. Proc., Pt. 6, 1965 Spec. Sess., p. 2186, comments by Senator Charles T. Alfano (“[w]e feel that [the electrical, plumbing, steamfitting and elevator repair] trades are of such a character that they are essential to the public health and safety, and they should be regulated on the state level”). As a remedial statute, we must afford it a liberal construction in favor of those whom the legislature intended to benefit. Knight v. F.L. Roberts & Co., 241 Conn. 466, 474, 696 A.2d 1249 (1997); Fruin v. Colonnade One at Old Greenwich Ltd. Partnership, 237 Conn. 123, 133, 676 A.2d 369 (1996). “In furtherance of that principle, exemptions or exclusions are to be strictly construed.” Success Village Apartments, Inc. v. Local 376, 175 Conn. 165, 168, 397 A.2d 85 (1978); State Board of Labor Relations v. West Hartford Board of Education, 177 Conn. 68, 74, 411 A.2d 28 (1979). Construing the term “industrial firm” to include virtually any commercial or business enterprise would be contrary to that principle. Indeed, the plumbing and piping work performed in a hospital is critical to the health and safety of its patients; as the defendants have explained, such work includes the installation and maintenance of water and gas lines for patient rooms, operating rooms, and laboratories and, therefore, it is likely the legislature intended those performing such work to meet the highest professional standards.17 Moreover, the plaintiffs acknowledge that *721our determination regarding the scope of the exemption created under § 20-340 (6) for plumbing and piping work is equally applicable to the electrical, fire protection system, elevator repair and installation, and heating and cooling trades. Thus, under the statutory construction espoused by the plaintiffs, the hospital, and all other business or commercial entities that provide services to the public, would be allowed to employ unlicensed personnel to perform any or all of its electrical work; see General Statutes § 20-330 (2);18 any or all of its elevator installation, repair and maintenance work; see General Statutes § 20-330 (7);19 any or all of its heating, piping and cooling work; see General Statutes § 20-330 (5);20 and any or all of its fire protection sprinkler *722systems work. See General Statutes § 20-330 (9).21 The significant additional public health and safety implications raised by a broad application of the exemption to those occupations militates strongly in favor of the less expansive interpretation of the term “industrial firm” urged by the defendants.
This case presents a good example of why the legislature, for purposes of granting exemptions under § 20-340 (6) from the licensure requirements of § 20-334, distinguished between firms engaged in manufacturing activities and firms engaged in other business or commercial pursuits. In the case of a firm or company involved in a manufacturing activity, the general public is unlikely to be affected by the plumbing and piping work performed at the manufacturing site. By contrast, faulty plumbing and piping poses a far greater public safety risk in the case of an enterprise that, like the hospital, provides services to the public. Moreover, manufacturing firms are far more likely than most other businesses to employ persons who, due to their mechanical and engineering training and skill, may be able to rectify problems arising from substandard plumbing and piping work performed by unlicensed personnel. Consequently, the legislature reasonably *723concluded that the need for licensed personnel is significantly less in the case of a firm engaged in manufacturing activities than it is for other business and commercial enterprises.
We conclude, therefore, contrary to the determination of the trial court, that the hospital is not an “industrial firm” within the meaning of § 20-340 (6). Accordingly, the plaintiffs are not exempt from the licensure requirements of chapter 393.
The judgment is reversed and the case is remanded with direction to dismiss the appeal.
In this opinion CALLAHAN, C. J., and BORDEN, J., concurred.

 Chapter 393 of the General Statutes sets forth a comprehensive scheme for the licensure of persons engaged in the following occupations: (1) electrical work; (2) plumbing and piping work; (3) heating, piping and cooling work, including solar installation, repair and maintenance work; (4) elevator installation, repair and maintenance work; and (5) fire protection sprinkler systems work. The licensure function for each of these occupations is performed, respectively, by the following five examining boards within the department of consumer protection: (1) the electrical work board; (2) the plumbing and piping work board; (3) the heating, piping and cooling work board; (4) the elevator installation, repair and maintenance board; and (5) the fire protection sprinkler systems board. See General Statutes § 20-331.

 The board is an agency of the named defendant, the department of consumer protection. See footnote 2 of this opinion. References hereinafter to the defendants include both the department of consumer protection and the board.

 The board alleged that each of the plaintiffs had violated certain statutory provisions from February 18, 1989, through May 9, 1994.

 General Statutes § 20-334 provides: “Certificate or card of registration. License. Suspension or revocation. No person shall engage in, practice or offer to perform the work of any occupation covered by this chapter in this state unless he has first obtained a license as provided [by the examination provisions] in section 20-333, or possesses a card of registration from the State Apprentice Training Division or the board and shall be subject to all the regulations established under this chapter for the purpose of governing apprenticeship training or has been issued a license for such particular work under this chapter prior to July 6, 1967. The Department of Consumer Protection shall furnish to each qualified applicant a license certifying that the holder thereof is entitled to engage in the work or occupation for which the person has been issued a license under this chapter, and the holder of such license shall carry it on his person while engaging in such work or occupation. Such license shall be shown to any properly interested person on request. No such license shall be transferred to or used by any person other than the person to whom the license was issued. Contractors shall display their state license number on all commercial vehicles used in their business and shall display such number in a conspicuous manner on all printed advertisements, bid proposals, contracts, invoices and on all stationery used in their business. The department shall keep a register in which shall be entered the names of all persons to whom such licenses are issued, and said register shall be at all times open to public inspection. Each board may suspend or revoke any license or certificate granted or issued by it if the holder thereof is convicted of a felony, is grossly incompetent, engages in malpractice or unethical conduct or knowingly makes false, misleading or deceptive representations regarding his work or violates the rules and regulations established under this chapter. Before any license is suspended or revoked, such holder shall be given notice and opportunity for hearing as provided in regulations established by the Commissioner of Consumer Protection. Any person whose license has been suspended or revoked may, after ninety days, apply to the board to have the same reinstated. Although § 20-334 has been amended since 1989, the time of the initial alleged violation; Public Acts 1991, No. 91-407, §§ 25, 42; there are no relevant substantive changes for the purposes of this opinion.
General Statutes § 20-337 provides: “Ownership of businesses. Nothing in this chapter shall require that the ownership or control of a business engaged in providing the work or services licensed under the provisions of this chapter be vested in a licensed person, but all the work and services covered by the definitions set forth in section 20-330 shall be performed by persons licensed for such work or occupation under this chapter.”
General Statutes (Rev. to 1997) § 20-341 provides: “Penalties for violations, (a) Any person who engages in or practices the work or occupation for which a license is required by this chapter without having first obtained an apprentice permit or a certificate and license for such work, or who wilfully employs or supplies for employment a person who does not have a certificate *712and license for such work or who wilfully and falsely pretends to qualify to engage in or practice such work or occupation, or who engages in or practices any of the work or occupations for which a license is required by this chapter after the expiration of his license, or who violates any other provision of this chapter, unless the penalty is otherwise specifically prescribed, shall be fined not more than one hundred dollars for each such violation.
“(b) The appropriate examining board may, after notice and hearing, impose a civil penalty on any person who engages in or practices the work or occupation for which a license or apprentice registration certificate is required by this chapter without having first obtained such a certificate or license, or who wilfully employs or supplies for employment a person who does not have such a license or certificate or who wilfully and falsely pretends to qualify to engage in or practice such work or occupation, or who engages in or practices any of the work or occupations for which a license or certificate is required by this chapter after the expiration of his license or certificate or who violates any of the provisions of this chapter or the regulations adopted pursuant thereto. Such penalty shall be in an amount not more than five hundred dollars for a first violation of this subsection, not more than seven hundred fifty dollars for a second violation and not more than one thousand five hundred dollars for each violation of this subsection occurring less than three years after a second or subsequent violation of this subsection, except that any individual employed as an apprentice but improperly registered shall not be penalized for a first offense.” Although § 20-341 has been amended since 1989, the time of the initial alleged violation; Public Acts 1989, No. 89-309; Public Acts 1991, No. 91-407, §§ 24, 42; Public Acts 1997, No. 97-263, § 6; there are no relevant substantive changes for the purposes of this opinion.

 As used in chapter 393 of the General Statutes, “ ‘[p]lumbing and piping work’ means the installation, repair, replacement, alteration or maintenance of gas, water and associated fixtures, laboratory equipment, sanitary equipment, other than subsurface sewage disposal systems, fire prevention apparatus, all water systems for human usage, sewage treatment facilities and all associated fittings within a building and shall include lateral storm and sanitary lines from buildings to the mains, swimming pools and pumping equipment, and shall include making connections to back flow prevention devices, and shall include low voltage wiring, not exceeding twenty-four volts, used within a lawn sprinkler system, but on and after July 1, 1984, shall not include solar work, except for the repair of those portions of a solar hot water heating system which include the basic domestic hot water tank and the tie-in to the potable water system and on and after April 1, 1989, shall not include the installation, repair, replacement, alteration or maintenance of fire prevention apparatus within a structure, except for standpipes which are not connected to sprinkler systems . . . .” General Statutes § 20-330 (3). Although § 20-330 (3) has been amended since 1989, *713the time of the initial alleged violation; Public Acts 1990, No. 90-194, § 1; there axe no relevant substantive changes for the purposes of this opinion.

 The board also alleged that Gelinas, a licensed plumber, had failed to display properly his contractor’s license number on his business cards. General Statutes § 20-334; see footnote 5 of this opinion.

 See General Statutes § 4-166.

 General Statutes § 20-340 provides: “Exemptions from licensing requirements. The provisions of this chapter shall not apply to (1) persons employed by any federal, state or municipal agency; (2) employees of any public service company regulated by the state Department of Public Utility Control or of any corporate affiliate of any such company when the work performed by such affiliate is on behalf of a public service company, in either case only if the work performed is in connection with the rendition of public utility service, including the installation or maintenance of wire for community antenna television service, or is in connection with the installation or maintenance of wire or telephone sets for single-line telephone service located inside the premises of a consumer; (3) employees of any municipal corporation specially chartered by the state of Connecticut; (4) employees of any contractor while said contractor is performing electrical-line or emergency work for any public service company; (5) persons engaged in the installation, maintenance, repair and service of electrical or other appliances of a size customarily used for domestic use where such installation commences at an outlet receptacle or connection previously installed by persons licensed to do the same and maintenance, repair and service is confined to the appliance itself and its internal operation; (6) employees of industrial *714firms whose main duties concern the maintenance of the electrical, plumbing and piping, solar, heating, piping and cooling, or elevator installation, repair and maintenance work of such firm on its own premises or on premises leased by it for its own use-, (7) the fabrication of electrical, plumbing and piping, fire protection sprinkler systems, solar, heating, piping and cooling or elevator installation, repair and maintenance equipment used in the production of goods sold by industrial firms; (8) persons performing work necessary to the manufacture or repair of any apparatus, appliances, fixtures, equipment or devices produced by it for sale or lease; (9) employees of stage and theatrical companies performing the operation, installation and maintenance of electrical' equipment if such installation commences at an outlet receptacle or connection previously installed by persons licensed to make such installation; (10) employees of carnivals, circuses or similar transient amusement shows who install electrical work, provided such installation shall be subject to the approval of the State Fire Marshal prior to use as otherwise provided by law and shall comply with applicable municipal ordinances and regulations; (11) persons engaged in the installation, maintenance, repair and service of electrical, plumbing, fire protection sprinkler systems, solar, and heating, piping and cooling equipment in and about single-family residences owned and occupied or to be occupied by such persons; provided any such installation, maintenance and repair shall be subject to inspection and approval by the building official of the municipality in which such residence is located and shall conform to the requirements of the State Building Code.” (Emphasis added.) Although § 20-340 has been amended since 1989, the time of the initial alleged violation; Public Acts 1996; No. 96-21, §§ 1, 3; there are no relevant substantive changes for the purposes of this opinion.

 The plaintiffs did not pursue their claim that the statutory licensure requirements were inapplicable to them on the ground that Rowe and Kalicharen had not performed plumbing work within the meaning of § 20-330 (3).

 See Public Acts 1965, No. 493. Prior to 1965, occupational licensing of the trades regulated under chapter 393 was done pursuant to municipal ordinance.

 When the licensure requirements were first adopted, only three exemptions were created, including the exemption for any person employed by an “industrial firm.” See White Oak Corp. v. Dept. of Consumer Protection, 12 Conn. App. 251, 256, 530 A.2d 641 (1987). The original three exemptions are essentially the same as the current versions of subdivisions (1), (2) and (6) of § 20-340. Id., 256 n.8.

 Webster’s Third New International Dictionary defines “industrial” as “of or belonging to industry.” “Industry” is defined as follows: “[a]: a department or branch of a craft, art, business, or manufacture: a division of productive or profit-making labor; especially]: one that employs a large personnel and capital especially] in manufacturing ... [b]: a group of productive or profit-making enterprises or organizations that have a similar technological structure of production and that produce or supply technically substitutable goods, services, or sources of income . . . . [c] manufacturing activity as a whole . . . .” Webster’s Third New International Dictionary. “Firm” is defined as “a business unit or enterprise. . . .” Id. Because both the plaintiffs and the defendants can find support for their claims in one or more of the definitions of the word “industry,” resort to the dictionary for the purpose of resolving the statutory construction issue raised by this appeal is not particularly helpful.

 See footnote 13 of this opinion.

 See footnote 9 of this opinion.

 We note that the pertinent legislative history sheds little light on the meaning of the term “industrial firm” under § 20-340 (6). There is nothing in the relevant legislative debate, however, indicating an intent by the legislature to exempt service providers, as distinguished from firms engaged in manufacturing activities, from the licensure requirements. Indeed, the limited debate about the licensure requirements, which focuses almost exclusively on the applicability of those requirements to a firm engaged in industrial manufacturing and construction, arguably suggests a contrary conclusion. Specifically, Senator Morgan McGuire raised the following concern about the applicability of the licensure requirements to steamfitters: “[T]here are many industries in the state lhathave great numbers of electrical workers, for example, great numbers of steamfitters. ... I know that at a place like [Electric Boat], a great portion of the personnel are steamfitters .... I do not think that this act should in any way, shape or form apply to those people who are engaged in industry doing the job as a part of an ultimate and later job . . . .” 11 S. Proc., Pt. 6,1965 Spec. Sess., pp. 2187-88. In attempting to assuage Senator McGuire’s concerns, Senator Paul Amenta, a proponent of the bill, reiterated that the provisions of the act “shall not apply to . . . employees of industrial firms, which Electric Boat would be ....’’ Id., p. 2189.

 It is trae that the hospital employs licensed plumbers who are responsible for supervising unlicensed persons in the performance of plumbing and piping work. Section 20-340 (6), however, contains no such requirement. Consequently, a business or commercial enterprise that is entitled to the exemption created under § 20-340 (6) need not employ any licensed plumbers.
The plaintiffs also maintain that there is no logical reason why the legislature would exempt persons employed by federal, state and municipal agencies from the statutory licensure requirements; see General Statutes § 20-340 (1); and not also exempt persons employed by private enterprises, like the hospital, which provide the same or similar services. We disagree. Contrary to the plaintiffs’ contention, it was reasonable for the legislature *721to entrust to each of those governmental entities the responsibility for regulatory oversight of its public agencies. The dissent argues that this reasoning is flawed because the state also is responsible for the regulatory oversight of some private agencies, as illustrated by the number of regulations that apply to hospitals. The dissent fails to acknowledge, however, that its proposed broad definition of service provider encompasses other service providers who are not as heavily regulated as hospitals, such as large corporations, insurance companies, restaurants, and private colleges. The lack of strict health and safety regulations affecting these businesses is all the more reason to believe that the legislature intended, as a minimal safety requirement, that the plumbers and electricians working on those buildings at least be licensed.

 General Statutes § 20-330 (2) provides in relevant part: “ ‘Electrical world means the installation, erection, maintenance, alteration or repair of any wire, cable, conduit, busway, raceway, support, insulator, conductor, appliance, apparatus, fixture or equipment which generates, transforms, transmits or uses electrical energy for light, heat, power or other purposes . . . Although § 20-330 (2) has been amended since 1989, the time of the initial alleged violation; Public Acts 1990, No. 90-194, § 1; there are no relevant substantive changes for the purposes of this opinion.

 General Statutes § 20-330 (7) provides: “ ‘Elevator installation, repair and maintenance work’ means the installation, erection, maintenance and repair of all types of elevators, dumb waiters, escalators, and moving walks and all mechanical equipment, fittings, associated piping and wiring from a source of supply brought to the equipment room by an unlimited electrical contractor for all types of machines used to hoist or convey persons or materials but does not include temporary hoisting machines used for hoisting materials in connection with any construction job or project . . . .”

 General Statutes § 20-330 (5) provides in relevant part: “ ‘Heating, piping and cooling work’ means the installation, repair, replacement, maintenance *722or alteration of any apparatus for piping, appliances, devices or accessories for heating systems, excluding sheet metal work; air conditioning and refrigeration systems, boilers, including apparatus and piping for the generation or conveyance of steam and associated pumping equipment . . . .”

 General Statutes § 20-330 (9) provides in relevant part: “ ‘Fire protection sprinkler systems work’ means the layout, on-site fabrication, installation, alteration or repair of any automatic or manual sprinkler system designed for the protection of the interior or exterior of a building or structure from fire, or any piping or tubing and appurtenances and equipment pertaining to such system including overhead and underground water mains, fire hydrants and hydrant mains, standpipes and hose connections to sprinkler systems, sprinkler tank heaters excluding electrical wiring, air lines and thermal systems used in connection with sprinkler and alarm systems connected thereto, foam extinguishing systems or special hazard systems including water spray, foam, carbon dioxide or dry chemical systems, halón and other liquid or gas fire suppression systems. . . .”