¶1Edward Waddington brought suit against Charles Wick and Mapleton Enterprises for the reasonable value of his architectural services. After a bench trial, the court entered judgment in favor of Waddington for $39,381.67, which it determined to be the value of the architectural service he had performed. On this appeal, Wick contends that the judgment should be limited to the contract price agreed upon by the parties. Reversed and remanded.
¶2Waddington filed a petition alleging that he had performed architectural services for Wick and Mapleton, a corporation in which Wick was the principal stockholder, for plans and specifications regarding the expansion and rehabilitation of the Holmes-dale Convalescent Center. Wick answered and attached a copy of a contract between himself and Waddington. Wick’s answer alleged the payment of certain amounts on a contract between himself and Wadding-ton, and alleged defective performance on the part of Waddington. Wick contended that if Waddington were entitled to anything, he was restricted to the contract amount less payments already made by Wick. Wick filed a counter-claim alleging both untimely and defective performance by Waddington.
¶3The court entered findings of fact in which it made no finding concerning the existence of a contract. However, Wick and Waddington agree that they entered into a contract
¶4There is no dispute that Wick desired to obtain a federally insured loan to rehabilitate the existing convalescent center, as well as add a new wing thereto. This fact was well known to Waddington at the time that the contract of November 21 was entered into. Although the contract made no reference to the estimated cost of construction of the rehabilitation and the new wing, the parties agree that Waddington estimated that the cost would be about $477,000. The fee to be paid to Waddington under the contract made no reference to any estimated or bid cost of the work, but rather was a flat fee.
¶5Waddington began work after signing the November 21 contract, and he completed the detailed plans and specifications on September 17, 1978. At that time, two contractors were invited to estimate the cost of construction. The lowest of these estimates was about $733,000. For several reasons, one of which was the excess of the contractor’s estimate over Waddington’s estimate, Wick abandoned the project.
¶6Waddington’s theory at trial and on this appeal is that Wick did not plan to add 20 private baths to 20 of the existing rooms, or plan for certain other engineering modifications at the time that the November 21 contract was signed. Waddington claims that the plans and specifications completed by him on September 17, 1978, contained both plans for making private baths in those 20 rooms and certain other engineering modifications, and that this constituted work outside the scope of the contract, for which he should be compensated. He also claims that the reasonable fee to which he is entitled is 6% of the contractor’s estimate of about $583,000 for the new wing, and 8% of the $150,000 estimate for rehabilitation. Waddington first claimed that he was entitled to payment in excess of the contract price in a bill which he submitted on September 25, 1978, well after he had completed all of the requested plans and specifications.
¶7The trial court found that the architectural services required as a result of the increase in the number of bathrooms by 20 and certain other engineering modifications constituted extra work on the part of Wad-dington. The court found that the reasonable fee due Waddington was 8% of the estimated cost of the rehabilitation work of $150,000, and 6% of the new construction estimate of $583,000.
¶8There is no doubt that a party may ignore an express agreement and bring suit for the reasonable value of services rendered. In such circumstances, the party is limited in recovery to the contract price. Boyd v. Margolin, 421 S.W.2d 761,767-68[9] (Mo.1967). This rule may be avoided, however, in cases where either the contract has been abandoned,
¶9*150In order to prove that a contract was abandoned, the abandonment must be demonstrated by positive and unequivocal acts and conduct which are inconsistent with a mutual intention to be further bound by the contract. Julian v. Kiefer, 382 S.W.2d 723, 729-30[8-14] (Mo.App.1964). In other words, an intent to abandon a contract is not enough. Rather, this intent must be carried into effect by an external act. Miran Inv. Co. v. Medical West Bldg. Corp., 414 S.W.2d 297, 303[9, 10] (Mo.1967).
¶10There have been no such positive and unequivocal acts demonstrating a mutual intention to abandon the contract in this case. This case arises out of a difference in opinion regarding the scope of the contract between Wick and Waddington. Specifically, the focus of the dispute is whether certain changes and modifications involving the addition of 20 bathrooms and other engineering modifications were within the scope of the contract. Thus, this case involves the construction of a contract, rather than the abandonment of one.
¶11Similarly, the extra work doctrine
¶12The extra work doctrine is generally applied to the relationship between a contractor or a subcontractor and an owner, rather than to the relationship between an architect and an owner. Thus in order to determine whether or not the parties contemplated, at the time of contracting, that Waddington was to provide architectural services for the 20 additional bathrooms and other engineering modifications, it is necessary to determine whether the extra work doctrine should be applied to the architect-owner relationship as well.
¶13The crucial focus of this inquiry is whether, in this context, the roles of architects and builder/contractors
¶14On the other hand a builder, or contractor, or building contractor, is one who contracts with an owner to build and erect the structure according to the plans developed by the owner and the architect. See, e.g., Black’s Law Dictionary 176 (5th ed. 1979) and 17 C.J.S. Contracts § 11 (1963).
¶15Thus, a builder does not stand in the same relationship to an owner as does an architect. At the time that an owner and an architect contract, the precise specifications of the structure are necessarily rather amorphous, since creating such plans and *151specifications is the very service for which the owner contracts with the architect. The relationship between the owner and the builder, however, is much more defined at the time their contract is entered into, since it is based on the plans and specifications developed by the architect.
¶16It follows from the above discussion that the extra work doctrine should not be applied to the relationship between Wick and Waddington. Thus, since neither this exception nor the abandonment exception is applicable, this case is governed by the general rule that in suing for the reasonable value of services rendered, a party’s recovery is limited to the contract price. This conclusion can be verified by examining the case law regarding the scope of an architect’s contractual duties arising out of an owner-architect contract.
¶17There are few cases which address this precise issue, and none of these are Missouri cases. Two cases in this category, however, are remarkably similar on their facts to this case. The most recent of these cases is Ingram v. State Property and Buildings Commission, 309 S.W.2d 169 (Ky.1957), which involves an architect’s suit against a property owner seeking compensation for services in excess of a fixed contract price.
¶18In Ingram, the contract provides for the building of “A Student Union Building,” without further details. The Wick-Wad-dington contract is similarly vague, calling for the building of “a new wing and rehabi-litat[ing] the existing facility totaling 120 beds for FHA Project No. 084-43041-PM-SR, known as Homesdale Convalescent Center, 8034 Holmes, Kansas City, Missouri.” Both contracts fail to provide further plans and specifications regarding the building to be built, which is understandable, since this is the very service which the architects were contracted to perform.
¶19In light of the lack of detail in describing the building, the Ingramcourt concluded that the architects had implicitly bound themselves to design a building which would ultimately meet with the approval of the owner. 309 S.W.2d at 171. The court used this implicit assumption in reaching its holding that labor alleged to be extra work by an architect was actually within the scope of the express contract. Id. at 173.
¶20The contracts in both the Ingramcase and this case also contain a provision wherein the architect agreed to provide all architectural, engineering, and consulting services. The two contracts differ in that only the Ingramcontract contains language stating that the architect agreed to make such changes and additions as the owner might request from time to time. Id. at 171.
¶21This distinction is not a crucial one, however. The language in Ingramindicates that the court’s conclusion that the architect bound himself to plan a building which would ultimately meet with the owner’s approval was drawn from the general nature of the discription of the building, and not from the changes and additions clause. Thus, applying the Ingramcase here would result in an inference being drawn that Waddington implicitly contracted to satisfy Wick, in spite of the absence of a changes and additions clause.
¶22Another distinction between Ingramand this case is that the Ingramcontract contains the following clause.
... the Architect’s fee is not subject to adjustment by reason of any higher bids received for the construction of the project or by reason of any change or addition within the scope of the contract. Id. at 170-71 (Court’s emphasis)
¶23The following seemingly inconsistent statement is contained in the Waddington-Wick contract:
12. The Owner agrees to pay, in addition to the contract price, the cost of any supplementary drawings required by reason of construction changes (emphasis added).
¶24The apparent inconsistency between these clauses is that the Ingramcontract seems to say that additional compensation may not be received by the architect for extra, un-contemplated work, while the Waddington-Wick contract seems to say that additional *152compensation may be collected for such work.
¶25On a closer examination, however, it is clear that these clauses are not contradictory, and thus do not constitute a basis for distinguishing this case from Ingram. The Ingramcourt interprets the above clause as simply fixing an absolute maximum fee that the architect could receive for all work done within the scope of the contract. 309 S.W.2d at 172. Similarly, the contract in this case sets forth a maximum fee receivable for performance of the contract. The above clause from the Waddington-Wick contract, both on its face and as interpreted by Waddington himself, relates only to supplemental drawings required by and during the course of construction. It does not apply to changes requested by the owner before construction is begun. Since construction was never begun in this case, the above quoted provision was never triggered, and the additional drawings requested by Wick were not required by “construction changes.” Thus, these additional drawings were within the scope of the contract, and not a cause for awarding Waddington an additional fee above the contract price.
¶26The other case which closely resembles this case is Osterling v. First Nat’l. Bank of Allegheny, 262 Pa. 448, 105 A. 633 (Pa.1918). The relevant portion of the Oster-ling contract states:
I propose and agree to furnish the plans, specifications, and detailed drawings necessary to erect your building, including supervision of the work, preparing of contracts, and the usual and customary services of an architect, for a commission of 5 per cent upon the cost of the work ... Id. at 633.
¶27This contract, like the Ingramand Wad-dington-Wick contracts and like owner-architect contracts in general, describes the structure to be built only in very general terms.
¶28While the 5 per cent commission on the total cost of the building in Osterlingwas paid without question, the architect sued, among other reasons,
... Osterling “proposed and agreed to furnish all necessary plans and specifications to erect the building.” This contemplated not only the plans which he had already prepared, but included any and “all” plans which in the process of erection might be called for. As an architect he was doubtless familiar with the fact that most owners in the course of building make changes in both plans and specifications, and he is fairly to be presumed to have contemplated just that ... Id. at 634 (emphasis supplied.)
¶29The provision in the Waddington contract that “[t]he architect agrees to provide all architectural, engineering, and consulting services” is, in practical terms, identical to the first part of the above quote.
¶30Apparently, the owner’s requests for additional drawings in Osterlingwere made both before and during construction, while Wick’s requests were made only before construction began. However, this factor does not preclude an application of the Osterlingholding here. The crux of both the Oster-ling case and this case is that when an architect contracts with an owner to provide full architectural services for the construction of a given building, it is implicit that during the course of the project, the owner may make changes in plans or specifications for the building, thus causing the architect to prepare additional and revised drawings to be included within the contractual fee. It follows that Wick’s post-contractual request that Waddington revise the drawings and specifications to add 20 bath*153rooms and incorporate other engineering and construction revisions were precisely the sort of changes that should be held to be within the scope of any such owner-architect contract.
¶31In conclusion, this case is governed by the general rule that in seeking recovery for the reasonable value of service rendered, Waddington is limited to the contract price. Since the trial court ignored the contract, it erroneously applied the law. Under Murphy v. Carron, 586 S.W.2d 80, 32[1] (Mo. banc 1976), the judgment must be reversed. The judgment in favor of Waddington is reversed, and this cause is remanded with directions to enter judgment in favor of Waddington for the contract price less payments, which is the sum of $12,370.76.
¶32SOMERVILLE, C.J., and MANFORD, KENNEDY and LOWENSTEIN, JJ. concur.
¶33WASSERSTROM, J., dissents and joins in separate dissenting opinion of NUGENT, J.
¶34NUGENT, J., dissents in separate opinion filed.
¶35. The dissent argues that the court could have concluded that the contract in this case was actually a sham, and that the parties did not attach importance to it. However, in both his supplemental brief and in the course of his oral argument, Waddington stated unequivocally that there was a contract.
¶36. The dissenting opinion makes the mistaken assumption that the contract in this case contains specific details regarding the design and contents of the building. In fact, the contract does not describe the building in any more detail than the language quoted above.
¶37. The trial court’s action is undoubtedly derived from the common practice followed in most owner-architect contracts wherein the architect’s fee is figured as a percentage of the ultimate construction cost rather than a fixed fee. The advantage of the percentage based fee is that it avoids the kind of dispute involved in this case, which arises when, due to architectural modifications requested by the owner in the designing stage, the final projected construction cost of the project is significantly greater than the initial projection. In this case, the parties presumably chose to contract for a fixed fee rather than a percentage based fee because they believed that this arrangement was in their mutual best interest.
¶38. This abandonment exception pertains only to the abandonment of an owner-architect contract in favor of the adoption of a different written or implicit agreement over the course of the time that the services in question were , being rendered. The dissenting opinion mistakenly confuses the abandonment of a contract with the abandonment of a project. Obviously, the project involved in this case was abandoned, in that building and rehabilitation were never actually begun. However, the abandonment of the project in no way consti-*150tued an abandonment of the contract, since Waddington had contracted merely to provide whatever architectural services were required in connection with the project.
¶39. A distinction is sometimes made between extra work, additional work, and alterations. Additional work is work necessarily required in the performance of the contract, but the necessity of which arises from unanticipated conditions. Alterations are changes in the form of the work which do not destroy its identity. See generally 7 A.L.R. P.O.F.2d 248, n. 32 and accompanying citations.
¶40. The terms builder and contractor are synonymous. See State v. Clark, 43 Wash. 664, 86 P. 1067 (Wash.1906).
¶41. The other three grounds offered in support of the architect’s claims for an additional fee were for his services as an arbitrator under a clause in the contract, payment for the value of material from the old building used in the new building, and a claim for payment to compensate for a construction delay. 105 A. at 633.
¶42. The dissent relies on Fitzgerald v. Walsh, 107 Wis. 92, 82 N.W. 717 (1900). In that case, the architect contracted to draw plans for a building. He drew the plans, and they were accepted by the owner. The owner subsequently ordered a- second set of plans for an entirely different structure, which the architect prepared. The architect sued in quantum meruit for drawing the second set of plans. These facts readily distinguish that case from the case at bar, since Waddington only prepared one set of plans for one structure.