[1] The plaintiff contends, for the first time in this court, that the zoning ordinance was invalid because the City failed to positively establish that a mistake had been made in the original ordinance adopted in 1953, or that the character of the neighborhood had changed, or that public safety, health, morals and general welfare required the change. These contentions differ substantially from the theory of plaintiff’s case as it was tried below. There, plaintiff conceded the validity of the ordinance except insofar as it affected the portion of its property changed from “business or commercial” classification to “office or institutional” classification, and as to that portion plaintiff contended the ordinance was invalid as unreasonable and confiscatory. The plaintiff may not now change the theory on which this cause was tried and judgment rendered in the trial below. State v. Brooks, 275 N.C. 175, 166 S.E. 2d 70; Board of Education v. Waynesville, 242 N.C. 558, 89 S.E. 2d 239; 1 Strong, N.C. Index 2d, Appeal and Error, § 4. Conceding arguendo that the burden of showing the reasons for a change in zoning might under certain circumstances rest upon a municipality, the theory of plaintiff’s pleadings and evidence in this case has never placed that matter in issue. Certainly the City cannot now be called upon to come forward with’ evidence which was unnecessary for it to present at the trial.
We therefore consider only the question raised by defendants’ exceptions and assignments of error, which is: Was the evidence presented sufficient to support a judgment declaring the zoning or*637dinance invalid, unenforceable and void as it relates to that portion of plaintiff’s property about which complaint is made?
[2-4] The presumption is that a zoning ordinance is valid and a constitutional exercise of the police power. Durham County v. Addison, 262 N.C. 280, 136 S.E. 2d 600; Kinney v. Sutton, 230 N.C. 404, 53 S.E. 2d 306. The burden to show otherwise rests upon a property owner who asserts that it is invalid. Raleigh v. Mor and, 247 N.C. 363, 100 S.E. 2d 870; Durham County v. Addison, supra. Evidence that an ordinance has made property less valuable is an insufficient ground, standing alone, for invalidating it. Zopfi v. City of Wilmington, 273 N.C. 430, 160 S.E. 2d 325; In re Appeal of Parker, 214 N.C. 51, 197 S.E. 706. “When the most that can be said against such ordinances is that whether it was an unreasonable, arbitrary or unequal exercise of power is fairly debatable, the courts will not interfere.” In re Appeal of Parker, supra, at p. 55. Under such circumstances the courts may not substitute their judgment for that of the legislative body as to the wisdom of the legislation. Zopfi v. City of Wilmington, supra; Schloss v. Jamison, 262 N.C. 108, 136 S.E. 2d 691.
[5] It is well settled, however, that zoning cannot render private property completely valueless. “[I]f the application of a zoning ordinance has the effect of completely depriving an owner of the beneficial use of his property by precluding all practical uses or the only use to which it is reasonably adapted, the ordinance is invalid.” Helms v. Charlotte, 255 N.C. 647, 653, 122 S.E. 2d 817. 8 McQuillin, Municipal Corporations, § 25.45.
[6] Applying the above principles, we hold that the plaintiff could not prevail merely upon a showing that the property in question could be more profitably and efficiently used for business or commercial use. What plaintiff had to establish was that the property could not reasonably be adapted to any use permissible under the challenged zoning regulation; and that that fact rendered the property valueless or virtually so.
Under the challenged zoning ordinance, the office and institutional classification, though prohibiting commercial and industrial uses, nevertheless permits a broad variety of other uses. Section 5.6 of the Ordinance provides as follows:
“The O & I Office and Institutional District is established as the district in which the principal use of land is for residences, general business offices and professional offices, and institutional type uses such as hospitals, medical offices and clinics. . . .
*638A. PERMITTED USES
a. Accessory uses clearly incidental to a permitted use and which will not create a nuisance or hazard.
b. Any use permitted in RA-6 Residential District.
c. Tourist homes and boarding houses.
d. Agencies rendering specialized services, such as real estate, insurance, advertising, brokerage, stenographic, telephone answering, and similar services, not involving retail trade with the general public nor maintenance of a stock of goods for sale.
e. Drug Stores.
f. Offices rendering professional services, such as legal, medical, dental, engineering, architectural and similar institutions.
g. Public and private colleges, universities, business colleges, music conservatories, dancing schools, day nurseries and kindergartens and similar services.
h. Offices and headquarters of civic, charitable, political, fraternal, social and religious organizations.
i. Funeral homes, undertaking establishments, and mortuaries.
j. A commercial parking lot.
k. Signs, advertising goods or services sold on the premises not to exceed one (1) square foot of area per lineal foot of lot abutting on a walk, drive or public way, or facing a private access way if there is no frontage on a public street.
l. Signs required by governmental agency or law to promote the health, safety and general welfare of the residence.”'
[7] The burden of proving that the property in question could not, be adapted for any of the permissible uses set forth above was on the plaintiff. In our opinion the findings of the court below do not support its conclusions respecting the effect of the zoning regulations on plaintiff’s property, nor do we feel that the evidence offered would permit findings sufficient to support such conclusion.
Except for certain stipulations and admissions the only evidence offered was the testimony of two witnesses for the plaintiff. The realtor who had been attempting to sell the property testified and described the property and the surrounding area from memory-*639When asked his opinion as to whether the property could be applied to institutional use, he replied:
“From a realtor’s standpoint, the highest and best use for this piece of property would be commercial, but the City in community planning does not always necessitate the highest and best use. I think I can safely say with the experience I have had in trying to merchandise this piece of property, that an offer of somewhere around seventy thousand, sixty-five thousand to seventy-five thousand, is as high as has been entertained by any of the prospects I have shown it to. That is, for the classification commercial. I have not had anyone make me an offer when I was handling it for institutional or office use. An institutional use was contemplated by the Elks, the Elks Club, but I was not at their meeting and do not know what was the cause of them rejecting the idea.
I think it would be expensive to adapt it to the use of institutional or for office use, probably more than would be justified in completely rebuilding.”
As to the possible use of the subject property for residential use the witness stated:
“In order to make the property usable for residential purposes, the building would have to be torn down, completely demolished. I am not qualified to give an opinion as to the expense of that. With respect to what would have to be done to remove the present building, there are several tons of steel supporting a large metal roof and a large area of concrete. I believe you have someone here who can tell the exact dimensions. I think it is six inches in the bottling area and four inches in the storage area, and it would require quite a demolition crew to tear it up. I don’t think there’s enough salvage material in it to get it done for free, but I am not qualified to tell you what it would cost.”
On cross-examination the realtor engaged in various calculations concerning the number of lots that could be obtained for residential purposes and testified that the zoning classification would permit multi-housing units. The only other witness was the president of the defendant corporation. Nothing in his testimony indicated that it would be impractical to adapt the property to a use permissible under a classification of office or institutional.
Taking the plaintiff’s evidence in its most favorable light we find that all it shows is that the property in question would be more *640valuable in the market place under a business or commercial zoning classification. That is not an unusual consequence of zoning, for the nature of such regulations is to deflate some property values while inflating others. But as is recognized by authorities heretofore cited, depreciation in value is not the test used in seeking to detérmine the validity of a zoning ordinance. Nor could it be, for such a test would necessarily result in the wholesale exemption of lots and tracts of land from any type of zoning regulation and would render ineffective the efforts of a municipality to orderly regulate the use of property for the common health, safety and welfare of its citizens. It is unfortunate that a property owner sometimes, as in this case, suffers hardship. But as stated by Barnhill, J., (later C.J.) in In re Appeal of Parker, supra, at p. 57:
“Each person holds his property with the right to use the same in such manner as will not interfere with the rights of others, or the public interest or requirement. It is held in subordination to the rights of society. He may not do with it as he pleases any more than he may act in accordance with his personal desires. The interests of society justify restraints upon individual conduct and also upon the use to which the property may be devoted. The provisions of the Constitution are not intended to so protect the individual in the use of his property as to enable him to use it to the detriment of the public. When the uses to which the individual puts his property conflict with the interest of society the right of the individual is subordinated to the general welfare and incidental damage to the property resulting from governmental activities or laws passed in the promotion of the public welfare is not considered a taking of the property for which compensation must be made.”
The plaintiff contends that it is faced with a situation similar to that of the landowner in the case of Helms v. Charlotte, supra. We do not agree. That case involved two lots with a combined useable area of less than 5,000 square feet. The ordinance required a minimum of 7,500 square feet for a residence. The dimensions and terrain of the lots were such that even if a residence could be legally constructed thereon, it would be “odd shaped” and would require a foundation and roof variation for each room. The court remanded the case for findings on the question: “Is it practical to use the lots for residential purposes and do they have any reasonable value for residential use under zoning regulations, the building code and other pertinent circumstances?” In the instant case there is nothing in the record before us to indicate that the plaintiff’s building which contains an office, lobby and substantial inside space has no reasonable *641value for one or perhaps several of the uses permitted under the present zoning classification. Nor'is there evidence as to the cost of removing the improvements in relation to the value of the land without the improvements. A vacant lot of the size here involved, located in an area such as has been described would certainly not be without value as a potential site for office or institutional construction.
Furthermore, in the Helms case the lot had not been previously used for business and therefore it had no value for a nonconforming use. Here, under the ordinance in question, the plaintiff may continue to use its property in the same manner it has used it for the past nine years as a permitted nonconforming use. It could be sold for that purpose. The ordinance specifically provides that the lawful use of a building and land existing at the time of the passage of the ordinance shall not be affected unless discontinued for a continuous period of more than 180 days. The property has been valuable for use as a storage warehouse for nine years. There is no evidence to indicate that its value for that purpose has been substantially affected.
Reversed.
Campbell and Paricer, JJ., concur.