We set out only so much of the issues as are necessary to an understanding of the matters herein disposed of.
On the 12th day of September, 1914, the plaintiffs filed an amended and substituted petition at law, in which they allege that, on or about the 1st day of June, 1911, they entered into an oral contract with the defendant, by the terms of which the defendant employed them to make certain alterations and improvements upon 'the residence property of the defendant, located in the town of Radcliffe; that these alterations and improvements were to he made according to the orders, directions and instructions given them by the defendant as the work progressed; that, among *3other things, they were to remodel, rebuild and improve the dwelling house, put in a cellar under the house, build porches, steps and walks, paint and plaster the building, and put on a new roof; that, for their personal labor in connection with the building of the house, they were to receive the customary compensation; that the defendant has fully paid the plaintiffs while employed in said work for all ordinary manual labor performed by them under said contract. It is further alleged that, in addition to the manual work so to be performed, the plaintiffs were employed to oversee and superintend the work upon the property, purchase such material as was necessary, at the defendant’s expense, look after the employment of labor, and generally oversee and superintend the work and see that it was done properly, and for this service, they were to receive a sum equal to 8 per cent of the total cost of the labor and material furnished and expense in connection therewith; that, in pursuance of the contract, they furnished the labor and material, all of which was paid for by defendant at a total cost of $8,707.60; that plaintiffs have fully complied with all that was required of them by the contract, and the defendant is indebted to them for superintending and overseeing the work a sum equal to 8 per cent of the total cost, or $696.60. For this they ask judgment.
In a second count to the petition, plaintiffs reiterate the facts herein set out in the first count, and ask to recover the fair, reasonable and customary value of the services rendered by them in overseeing and superintending the work, and ask on this count the same as prayed for in the first count.
1. PIjKading : ninendinents : shitting from equity to law: effect. It appears that this action was commenced originally in equity, and the plaintiffs sought to have established and foreclosed a mechanics’ lien against the property upon which the work was done. Upon the filing of this *4amended and substituted petition, defendant appeared, and filed a motion to strike it front the files, on the ground that the action, having originally commenced in equity, presented a new and separate cause of action, distinct from that alleged in the original petition, and not germane thereto. This motion was overruled. This presents the first complaint urged here.
It is not well taken. The ground is not tenable, as is apparent from an examination of the two pleadings. The change is only in the forum. The same cause was first presented in equity, and equitable relief prayed for. This amended and substituted petition presents a cause of action based upon the same facts, without any claim or basis for claim for equitable relief. That this is allowable, see Barnes v. Hekla Fire Ins. Co., 75 Iowa 11; Newman v. Covenant Mut. Ins. Assn., 76 Iowa 56; Rohrbach v. Hammill, 162 Iowa 131.
To this petition, then, the defendant filed an answer, in which he admits the employment of the plaintiffs to make alterations and repairs on his dwelling house, denies that the contract was as set out by the plaintiffs, and alleges that the agreement was that plaintiffs should personally superintend the repairs and construction, and would do the work in a good, first class, workmanlike manner, and in accordance with certain plans and specifications then furnished them by the defendant; that, upon the completion and acceptance of the work by the defendant, defendant would pay plaintiffs’ firm a bonus of 8 per cent upon all material and labor that went into the construction of the dwelling house, not, however, including the following, items: (1) All interior decoration, painting of every kind, both labor and material. (2) All cement work. (3) All plumbing and heating, and all work in connection therewith. (4) All plastering and mason work. (5) All material used in the *5garage, and labor on the same. (6) All material purchased by the plaintiffs themselves and used by them on other buildings than the dwelling house. (7) Any shingles except those used upon the dwelling house.
It was expressly agreed that the plaintiffs should give their entire time to overseeing the purchasing of material and seeing that the same complied with the specifications, and personally supervising all work upon the house, and seeing that the same ivas done according to the specifications furnished them. Defendant says that plaintiffs failed to supervise the work as agreed, and failed to do the work in a workmanlike manner, and failed to complete it within the time specified in the contract; that the defendant furnished the material on demand of plaintiffs, paid all bills promptly, and performed all parts of his contract.
To simplify the ease, it may be well to say, nt this time, that the record discloses that the plaintiffs were employed to superintend and supervise the construction of this building; that the building was constructed at a total cost-shown by the following stipulation: The cost of labor and material in the home premises of the defendant was $8,130.81, exclusive of heating and plumbing, and the cost of the shingles that went into other buildings was $559.86. To further simplify, we may say that the allegation of the plaintiffs petition that the work was to be done “according to the directions and instructions given them by the defendant as the work progressed,” is not supported by the evidence. It appears that the real contract was that the ■work was to be performed according to the plans and specifications furnished them by the defendant at the time the contract was entered into.
*6Contracts: action for broach : pleach ing: express contract excludes <xuantmti meruit. The record as finally made shows, and both parties agree, that tlie contract provided that plaintiffs were to receive 8 per cent of the total cost of the reconstruction and repair of this building, except certain matters which, though a part of the cost or connected with the reconstruction, defendant claims were not to be estimated and included in figuring the total cost on which plaintiffs’ compensation of 8 per cent was to be figured.
So, in this last analysis, the controversy between the plaintiffs and the defendant centers around this proposition, so far as the plaintiffs are concerned: What work in connection with the building did the contract cover? On .what work and material entering into the construction of the building Avas plaintiff entitled to receive a commission of 8 per cent? Both agree that the Avork Avas to be done according to plans and specifications furnished by the defendant to the plaintiffs. Both' agree that plaintiffs were to have 8 per cent of the cost of said building, except as-to items disputed by defendant hereinbefore set out in his ansAver. Tt is apparent, therefore, that a contract Avas made betAveen these parties, and the method of computing the compensation fixed by the contract. The only difference is as to the work to be considered in connection with the reconstruction of the house in estimating this compensation. When that Avas- settled and determined, the compensation Avas fixed at 8 per cent. However, upon the trial, the court seems to have recognized the right of the plaintiffs, notAvithstanding the admitted contract, to prove what the services Avere reasonably worth in superintending and overseeing the matters covered by (heir contract, Avhatever that might be; and of this, complaint is made.
The court submitted both counts of the petition, the right to recover on the contract and the right to recover on quantum meruit, and permitted Avitnesses, over the ob*7jeetion of the defendant, to testify as to Avhat the sendees of the plaintiffs Avere reasonably worth in supervising and superintending the reconstruction of this building.
This is the second error assigned, and avc think it is Avell taken. The mere pleading of a claim upon quantum meruit does not entitle the plaintiff to prove Avhat his services Avere reasonably worth, in the face of a record shoAving conclusively that there was an express contract between the parties fixing- the compensation. Where parties agree upon the compensation to be awarded for sendees, that agreement controls and gOA'erns the parties in the assertion of any rights, and fixes the measure of compensation.
There is some dispute as to the terms of the contract in respect to the work to be covered by the contract. There is no dispute as to the method of ascertaining the compensation AA'hen the other is ascertained. When (he Avork Avas performed, the compensation avus fixed on the basis of 8 per cent of the actual cost of the Avork covered by the contract. That was a fixed rate of compensation, and yet, in face of this, the court ailoAved witnesses to testify as to Avhat such sendees Avere reasonably worth. In Prouty v. Perry, 142 Iowa 294, 298, Division 2 of the opinion, this court said:
‘‘The parties did contract Avith reference to compensation. If the services rendered were Avithin the scope of that contract, there avus no quantum meruit involved. It is true that the terms of the contract were general. The amount of labor to be performed Avas necessarily more or less uncertain, but tire nature and scope of it Avere reasonably defined. The amount of compensation to be received Avas more or less uncertain, but the measure and the method of its ascertainment Avere reasonably defined.”
So here, the amount, of work Avas uncertain. The -sum to AA’hich plaintiffs-might ultimately be entitled was uncer*8tain., but the method oí its ascertainment was fixed by the contract and controlled the parties, and no evidence as to what it was reasonably worth, whether more or less or the same as the contract price, was competent to be received or to be considered by the jury.
In the case at bar, the amount asked under the quantum meruit count, oí course, is the same as that asked under the count based on the contract, and the quantum meruit count does not ask for more than was asked for in the count on the contract; but evidence was permitted to go to the jury tending to show that the services were worth more than the contract called for — more than the party would be entitled to under the terms of. his contract. This was clearly incompetent.
3. Appeal and error : review : presumption : commingling quantum meruit and express contract. It may be argued that this was not prejudicial, because the court instructed the jury, on the second count of the petition, that they might allow plaintiffs the reasonable value of the services rendered, but not to exceed 8 per cent of the actual cost. It may be argued, therefore, that this evidence was without prejudice, inasmuch as both parties agreed that the measure was to be 8 per cent. This argument does not appeal to us, for the reason that we recognize in juries a disposition to adjust the burden of losses that may follow ev.en the faithful performance of a burdensome contract. Further, the disposition to do equity, which we find in most jurors, is appealed to. In this case, it is claimed that plaintiffs did not perform their contract according to its terms. This sort of testimony serves as a basis of adjustment in the minds of the jury, and suggests a balancing off of the loss which the plaintiffs sustained because of the inadequacy of the consideration in their contract, against the loss resulting to the defendant for a failure to perform the contract according to its terms; and thus a door for speculation is opened *9to the jury that ought to be kept closed. liven though the contract is iniprovidently made, and the consideration is less than it ought to be, — less than is reasonable, — yet the contract controls, and the lights of the parties must be ascertained and determined by the contract. We think there was clearly prejudicial error in the admission of- this testimony, and for that reason the cause must be reversed.
4. grounds ói estoppel: inconsistent eon-objections. In view of another trial, it is well for us to say that, so far as the plaintiffs’ claim concerned, their duty tp the defendant was that of overseers and inspectors, superintendents of the work to be done for the defendant under the plans and specifications submitted. They were selected as experts on these lines, and their services secured and paid for because of the benefits which were supposed to flow to the defendant by reason of their superior skill and knowledge in respect-to the matters entrusted to them. The house could be built without an overseer or inspector. It therefore became their duty to exercise that skill and learning which is required of one in that business in the neighborhood, and to give time and attention to see that the work was done substantially according to the plans and specifications. It was their duty to see that the work was done in a good, workmanlike manner. From the nature of the contract, the law implies a duty to exercise that skill, diligence, care and learning that are usually employed to bring the work to a successful issue. It follows, therefore, that the court Avas wrong in saying, as a general proposition, that, if the defendant Avas present and saw the work progressing, and made no objection, he would be estopped to make objection now. Defendant had a right to rely upon the plaintiffs' to perform their contract. To perform their contract required that they superintend and oversee the Avork, to the end that, when finished, it might comply with the plans and specifications which were their *10guide as to what was required to be done to make the contract complete. The workmen were under their control, and supervision. The material was purchased by them, and should have been purchased to comply with the plans and specifications. The workmen were chosen by them, and it was their duty to supervise their work, inspect it, and see that it was done substantially as called for by the plans and • specifications. See Smith & Nelson v. Bristol, 33 Iowa 24. Of course this would not be true as to changes from the plans and specifications made on the direction of the defendant, or at his request. Such changes would not be subject to this rule; nor could the plaintiffs be holden liable for any defects in the plans and specifications. An acceptance of the building, when completed, would not constitute a Avaiver of any of the defendant’s otherAvise just and legal claims. This was the defendant’s home. He was occupying it. He could not do ether than ..accept it? and such acceptance does not relieve the plaintiffs from responsibility for the faithful performance of their contract.
There are other errors assigned, but, as Ave are satis, fled that they will not arise on another trial, Ave do not take the time to dispose of them uoav. Indeed, some of the errors could not reasonably arise again, upon a fair presentation of the record on another trial.
For the. errors pointed out, the cause is — Reversed.
Laud, Salinger and Stevens. JJ., concur. Evans, J., dissents.