The plaintiffs, Robert and Ernest Fried-lander, acting in their capacity as trustees, *967appeal from summary judgment entered in favor of the defendants by the Superior Court (Androscoggin County). Plaintiffs unsuccessfully sought a judgment declaring a restrictive covenant in a deed to be invalid and unenforceable. Plaintiffs argue on appeal that summary judgment should not have been granted because: (1) a material issue of fact remains as to the intent of the parties to the covenant; and (2) the court failed to determine that the covenant was reasonable in scope and duration. We find no error and we deny the appeal.
I.
The record before this Court may be summarized as follows: By deed dated February 1, 1963, defendant Hiram Ricker & Sons, Inc. (Ricker) conveyed to the Whiting Milk Company (Whiting) a two-acre parcel of land located on the westerly side of Route 26 in Poland Spring, Maine. Situated on the rear of the lot, was the residential building referred to in the deed as the Campbell Cottage. The deed contains the following language:
The premises hereby conveyed are to be used as a single family dwelling only. (Emphasis in original)
Through mesne transfers, plaintiffs now hold title to the Campbell Cottage property in trust. After the original conveyance in 1963, Ricker continued to own land surrounding the Campbell Cottage lot on the westerly side of Route 26, as well as land on the easterly side of the highway. On the land it retained, Ricker operated a convention center including a hotel and various recreational facilities. In 1982, defendant Image, Inc. (Image) purchased the Ricker property and granted Ricker a purchase money mortgage that remains outstanding.
Plaintiffs commenced the present action in 1983 by filing a complaint pursuant to the Uniform Declaratory Judgments Act (14 M.R.S.A. § 5951 et seq. (1980)). The complaint sought a declaration that the restrictive covenant was invalid and unenforceable. After responsive pleadings were filed, plaintiffs moved for summary judgment. Affidavits were filed in support of the motion, by plaintiff Robert Friedlan-der, and opposing affidavits were filed by Mel Robbins, president of Image, and by Saul Feldman, president of Ricker. After hearing, the Superior Court entered summary judgment against plaintiffs as the moving parties and found the restrictive covenant to be valid and enforceable. From this judgment plaintiffs appeal.
II.
In granting summary judgment for defendants, the Superior Court found that “[t]he covenant in this case runs with the land and is enforceable by Defendant Image, Inc.” Plaintiffs contend that at least a material issue of fact remains whether the parties to the covenant intended that it should run with the land. Ordinarily the issue whether a restrictive covenant was intended to benefit the adjoining land retained by the grantor is determined by an interpretation of the written instrument. The subject covenant offers little assistance in this regard. No reference is made in the covenant to “running with the land”, “benefiting the parcel retained by grantors” or binding “heirs, successors and assigns.” In such circumstances, where it is necessary to resort to extrinsic evidence, a genuine issue of fact will normally be presented and the granting of summary judgment will be precluded. See Brown v. Heirs of Fuller, 347 A.2d 127, 129 n. 4 (Me.1975).
In the present case, the Superior Court found on the basis of the affidavits submitted by defendants that the restrictive covenant was intended to benefit and run with the Ricker land. The court committed no error in coming to this conclusion. On the record before the Superior Court, there was no genuine issue of fact concerning the intent of the parties to the 1963 deed. Defendant Ricker presented the affidavit of its president, Saul Feldman, who attested to the fact that he was a party to the negotiations and that the cove*968nant was included with the intent to benefit the retained land of Ricker. Plaintiffs’ sole counter to this assertion is set forth in the affidavit of plaintiff Robert Friedlander, wherein he states:
Since my father [the principal of Whiting] had just finished negotiating a sale of the Poland Spring Inn Property at the time the Campbell Cottage was conveyed, I believe that the restriction in the Campbell Cottage Deed was simply intended to operate as a personal restrictive covenant to prevent my father or our family from going into competition with Poland Spring Inn from the Campbell Cottage site.
The Superior Court correctly concluded that the evidence presented by defendants was unrefuted because the assertions contained in the Friedlander affidavit were inadmissible on grounds of hearsay and lack of personal knowledge. M.R. Civ.P. 56(e); Richards Realty Co. v. Inhabitants of Castle Hill, 406 A.2d 412 (Me. 1979).
III.
Finally, plaintiffs contend that “the Superior Court failed to consider an essential and dispositive factor in this case, the reasonableness of the restriction.” Plaintiffs fail to appreciate the posture in which this case is presented. Essentially, they are claiming that the covenant is facially invalid on the ground that the breadth of the restriction deprives them of any reasonable economic return. The asserted impact on the present use of the premises as a single family dwelling, when viewed in a vacuum, is insufficient to defeat an otherwise valid restrictive covenant. The constraints of reasonableness that arise from considerations of policy relate to the enforceability of the covenant in equity rather than its facial validity. See Day v. McEwen, 385 A.2d 790 (Me.1978); LaGrange v. Datsis, 142 Me. 48, 46 A.2d 408 (1946); Roy v. Bolduc, 140 Me. 103, 34 A.2d 479 (1943). The present action does not seek enforcement against a change in the use of the premises. Although it is true that a covenant will be enforced in equity only if it is reasonable under the circumstances, that same consideration is not present in a suit seeking a declaration of facial validity without any allegation of the use proposed for the premises. Because of the narrow inquiry presented by the subject action, the Superior Court committed no error in declaring the covenant to be valid. The issue of the extent to which a court of equity would grant enforcement, must await further development.
The entry is:
Judgment affirmed.
NICHOLS, YIOLETTE, GLASSMAN and SCOLNIK, JJ., concurring.