The issue before us is whether a provision in a charter municipality’s Zoning Code, intended to protect a permitted nonconforming use, should be interpreted to prevent enforcement of a valid health, safety and welfare regulation in the municipality’s Fire Prevention Code. For the reasons to follow we hold for the municipality and reverse the appellate court decision.
I
The appellate court construed the off-street parking requirements contained in Chapter 923 of the Fire Prevention Code in pari materia with Chapters 711 and 715 of the Zoning Code to prevent enforcement of the Fire Prevention Code. We cannot agree for a number of reasons.
First, Section 711.01(v) defines “Zoning Code,” as used in Section 711.05, as follows: “ ‘Zoning code’ means Ordinance 450, passed June 13, 1938, as amended.” While this “Zoning Code” definition expressly includes Part Seven of the Codified Ordinances of Gates Mills, it does not include any other ordinance provision. Second, Section 711.02, a provision entitled “Interpretation; Purpose,” indicates “[t]his Zoning Code shall not repeal, abrogate, annul or in any way interfere with any existing provi*168sions of law or ordinance * * *.” In short, the Zoning Code indicates it cannot be read in pari materia to abrogate or interfere with any other section of the Gates Mills Codified Ordinances. Because a clear intent was manifested for the Zoning Code to be interpreted separately from the remaining code parts, use of the statutory interpretation doctrine of in pari materia in this case is inappropriate. Cicerella v. Jerusalem Bd. of Zoning Appeals (1978), 59 Ohio App. 2d 81 [13 O.O.3d 99]; cf. Brauer v. Cleveland (App. 1964), 94 Ohio Law Abs. 464, 467 [31 O.O.2d 348].
Third, at the time of its enactment, Section 923.01 of the Fire Prevention Code was applicable only to “any building or structure designed or intended for institutional, retail business or office use” constructed or altered after the passage of the ordinance. (June 30, 1959.) Section 923.02 reads in pertinent part:
“WHEN REQUIRED.
“Accessory off-street parking facilities, including access driveways, shall be determined in conformance with this chapter and shall be provided for as a condition precedent to the occupancy and use of such building or structure:
“(a) Whenever a building or structure is constructed or a new use established * * * [or]
“(b) Whenever the use of an existing building or structure is changed to a use requiring more parking facilities, or whenever an existing building is altered and there is an increase in the seating capacity or floor areas of the building or structure * * *.”
In effect, even after passage of Chapter 923, appellee’s restaurant continued to operate lawfully, with only fourteen off-street parking spaces, because this ordinance contained a “grand-father clause,” Section 923.02, which allowed those operations, which predated this legislation, to continue lawful existence. Thus, appellee’s business was not, as it contended, ever “a valid non-conforming business.”
Fourth, the term “nonconforming use” is a term of art. This term is employed to designate a use of property which was lawful prior to the enactment of a zoning ordinance and which use may be continued after the effective date of the ordinance even though it does not comply with the applicable use restrictions. R.C. 713.15; State v. Pierce (1956), 164 Ohio St. 482 [58 O.O. 325]. Logically then, a permitted use is not a nonconforming use. The use of this building as a restaurant was always, and would still be, a conforming use under the Zoning Code. Since appellee’s building was never a nonconforming use, the Zoning Code use exception provision is clearly inapplicable and the trial court was correct in granting summary judgment as a matter of law.
II
Appellee argues “that it had a vested interest in the right to use its property as a nonconforming use, which right was protected by the Constitution, State Statute, Municipal Ordinance and the Decree of the Com*169mon Pleas Court of Cuyahoga County, Ohio.” Although we have resolved appellee’s argument, that the property was a proper nonconforming use, against appellee, an additional observation is appropriate. Both conforming and nonforming uses are subject to ordinances and regulations of a police nature predicated upon protection of the public health, safety, welfare, and general good.2 See, e.g., Goldblatt v. Hempstead (1962), 369 U.S. 590; Akron v. Klein (1960), 171 Ohio St. 207 [12 O.O.2d 331]. An owner of property does not acquire immunity against the exercise, by a municipality, of its police power because such owner began his original operation or use of property in full compliance with existing laws. As stated by the Supreme Court in Queenside Hills Realty Co. v. Saxl (1946), 328 U.S. 80, 82-83:
“Little need be said on the due process question. We are not concerned with the wisdom of this legislation or the need for it. * * * Protection of the safety of persons is one of the traditional uses of the police power of the States. * * * Many types of societal legislation dimmish the value of the property which is regulated. * * * “But in no case does the owner of the property acquire immunity against exercise of the police power because he constructed it in full compliance with the existing laws. * * * The police power is one of the least limitable of governmental powers, and in its operation often cuts down property rights. * * * The question of validity turns on the power of the legislature to deal with the prescribed class. ”3 (Emphasis added; citations omitted.)
Pursuant to R.C. 3781.11, municipalities may require all building repairs and construction to conform to current building codes.4 Such regulatory legislation, enacted pursuant to a state or municipality’s police power, will be enforced so long as such power is not exercised arbitrarily. Hadacheck v. Sebastian (1915), 239 U.S. 394. The specific legislation in this case, Chapter 923, was adjudged to be a “valid and legal ordinance” by the *170Court of Common Pleas of Cuyahoga County in the case of Gates Mills v. McNally-Doyle Restaurants, Inc. (Feb. 3, 1964), Cuyahoga C.P. No. 788040, unreported. Additionally, as noted by this court, in Brown v. Cleveland (1981), 66 Ohio St. 2d 93, 96 [20 O.O.3d 88]:
“* * * [Accessory off-street parking requirements * * * are rationally related to several safety hazards which the city may lawfully regulate pursuant to its police powers: protection of pedestrians and drivers, elimination of traffic congestion and reduction of air and noise pollution.”
Accordingly, this ordinance, enacted pursuant to the proper exercise of appellant municipality’s police powers, is enforceable. Any vested interest which appellee might have had in the right to maintain the use of its property would be subject to such legislation. In Hadacheck, supra, at 410, the court stated:
“It is to be remembered that we are dealing with one of the most essential powers of government, one that is the least limitable. It may, indeed, seem harsh in its exercise, usually is on some individual, but the imperative necessity for its existence precludes any limitation upon it when not exerted arbitrarily. A vested interest cannot be asserted against it because of conditions once obtaining. * * * To so hold would preclude development and fix a city forever in its primitive conditions. There must be progress, and if in its march private interests are in the way they must yield to the good of the community.” (Citation deleted.)
Adoption of appellee’s position would have far-reaching consequences and might nullify or prevent appellant from enforcing other provisions of the Fire Prevention Code, such as the Ohio Fire Code (Chapter 941); plumbing and sewer regulations (Chapters 931-937); the National Electrical Code (Chapter 927); chimney and wall construction requirements (Chapters 915, 919). Based upon the foregoing law and logic we cannot accept appellee’s argument against enforcing the fire regulations.
III
Finally, appellee argues that the off-street parking issue was litigated in the 1963-1964 action and is thus barred from relitigation by the doctrine of res judicata. We disagree. The village in that action sought an injunction to prevent C.D.S. from expanding the restaurant without complying with off-street parking requirements. Although the present action refers to the same subject matter of off-street parking, the former judgment neither authorized nor prevented C.D.S. from continuing its operation as it existed. That issue was never litigated, and therefore res judicata is not a bar. See Goodson v. McDonough Power Equip., Inc. (1983), 2 Ohio St. 3d 193, 201; Trautwein v. Sorgenfrei (1979), 58 Ohio St. 2d 493 [12 O.O.3d 403], syllabus.
IV
It is apparent that appellee has no legal basis to support its stance in *171the cause at bar. Accordingly, we reverse the judgment of the court of appeals and reinstate the trial court’s judgment.
Judgment reversed.
Celebrezze, C.J., Looker, Holmes, Douglas and Wright, JJ., concur. Sweeney and C. Brown, JJ., separately concur in part and dissent in part.The fact that zoning ordinances in this state and elsewhere except preexisting uses of land from the operation of use restrictions can be explained on the basis of constitutional principles. An existing use is said to be the subject of a vested right in the user. As such, to prohibit such use by enforcing subsequently enacted zoning ordinances would amount to the taking of the user’s property without due process of law. Clifton Hills Realty Co. v. Cincinnati (1938), 60 Ohio App. 443; see, also, Cicerella v. Jerusalem Bd. of Zoning Appeals (1978), 59 Ohio App. 2d 31 [13 O.O.3d 99].
See Hadacheck v. Sebastian (1915), 239 U.S. 394; Block v. Hirsh (1921), 256 U.S. 135. See, also, Chicago, B & Q. RR. Co. v. Nebraska (1898), 170 U.S. 57; Hutchinson v. Valdosta (1913), 227 U.S. 303.
R.C. 3781.11 reads in pertinent part:
“The construction, alteration, erection, and repair of buildings * * * shall conform to the statutes of this state or the rules and regulations adopted and promulgated by the board of building standards, and to provisions of local ordinances not inconsistent therewith.” (Emphasis added.)
See, also, R.C. 3781.01; Myers v. Cincinnati (1934), 128 Ohio St. 235.