Giant Food, Inc. (Giant), a corporation engaged in the retail distribution of many lines of products — including the sale and installation of carpets — brought suit in the Superior Court for breach of contract. The defendants (Bender) 1 counterclaimed for breaches of contract and warranties. All of these claims pertained to the sale, installation, and replacement of carpets. After a nonjury trial, judgment was rendered in favor of Giant on its breach of contract claim, and in favor of Bender on its counterclaim based on a breach of an express warranty. The court calculated damages on both parties’ claims and deducted Bender’s amount from Giant’s to arrive at a net damage figure for Giant. Giant now appeals this award of damages, alleging the trial court erred in three respects: (1) by denying prejudgment interest to Giant on its contract claim; (2) by basing the breach of warranty damages on the cost of the replacement carpet rather than on the cost of the original carpet; and (3) in finding as a fact that the original carpet cost $8.21 per square yard installed rather than $7.31 per square yard installed. Bender cross-appeals the trial court’s finding that the open account arrangement between the parties ceased by spring 1978.
This dispute arose out of a 1968 contract between Giant and Bender for the installa *1297 tion of carpeting on all twelve floors of an office building at 1100 L Street, N.W. The specific type of carpet to be installed was manufactured by Seamloc Lomaloom Carpet Company (Lomaloom). Bender specified this type of carpet because it had demonstrated durability in Bender’s other buildings. 2 Pursuant to the contract, Giant installed Lomaloom carpet on the first ten floors during the middle of 1970, but then determined that it would be unable to fulfill its contractual commitment to install Lomaloom on the top two floors. Consequently, Giant offered to substitute carpet manufactured by North American Mills, Inc., which Giant assured Bender was equal to or better than the quality and durability of Lomaloom carpet. Bender agreed to the substitute carpet which was completely installed by about July 11, 1970.
During 1973, this substitute carpeting began to delaminate, i. e., the nylon face and rubber backing separated, resulting in areas of buckling throughout the eleventh and twelfth floors. The 1968 contract specified that all the carpeting would be guaranteed free from defects for five years. Bender contacted Giant about the defects and asked that the defective carpeting be replaced. Giant did not initially admit or disclaim any responsibility, but attempted to place the burden on North American Mills, which refused to replace the carpeting.
Despite continued correspondence between the parties as how properly to resolve the problem, Bender solicited a bid from Giant for replacement carpeting. In doing so, Bender indicated to Giant that it had already solicited and received a bid from Georgetown Carpet Company for the same job, and that Giant should attempt to beat that bid. 3 After some negotiations, Bender signed the bid letter — dated December 3,1973 — accepting Giant’s terms for the installation of new carpeting on the top two floors. Pursuant to the specifications of the December 3 letter, Giant installed new carpeting and requested payment by invoice dated February 1, 1974. Bender refused to pay, asserting that Giant was obliged to replace the defective carpeting pursuant to the terms of the 1968 contract. This suit followed.
The trial court found for Giant on its breach of contract claim against all defendants, based on its conclusion that the December 3, 1973 letter — signed by Bender— constituted a valid contract. Bender’s failure to pay was a breach of that contract, for which Giant was entitled to the full $40,139.92 price contained in the contract. However, the court did not award Giant prejudgment interest on that amount as authorized by D.C. Code 1973, § 15-108.
Bender was successful in its counterclaim because the trial court found Giant had breached its express warranty, in connection with the 1968 contract, to Bender as to the quality, durability, and future performance of the substitute carpeting. Because Bender had received three years’ use out of the five years of guaranteed nondefective use, the trial court awarded Bender damages for replacement of the carpet only for two years, or 40 percent of the cost of replacement. 4 It also awarded damages for work incidental to the removal of the defective carpeting and installation of the new carpeting in the amount of $4,675.50. Bender’s damages thus totalled $20,731.50. The court then deducted this amount from Giant’s award to obtain a total of $19,408.42 for Giant.
Giant’s major contention is that the trial court erred in declining to award prejudgment interest on its liquidated claim. *1298 In its conclusions of law the trial court ruled that
[t]he damages owed plaintiff by defendants, under the circumstances of this case, should be treated as though unliqui-dated, particularly in view of the fact that plaintiff was aware of the failure of the original carpeting to last as warranted and knew at all pertinent times that defendant had a substantial but unliqui-dated claim against plaintiff for the replacement of that carpeting. In the interest of justice, plaintiff should not be awarded interest.
(Memorandum Order at 10; footnote omitted.) The court cited 5 Corbin, Contracts §§ 1050, 1051 (1964), and stated its “view that D.C. Code 1973, § 15-108 should not be applied mechanically in a case of this type,
cf. Powers v. Metropolitan Life Insurance Co.,
Giant contends that its debt was liquidated and therefore falls within the language of the statute, which requires the allowance of prejudgment interest as a matter of law. The liquidated debt, it asserts, is the contract price for the replacement carpeting— $40,139.92. Giant argues that the trial court was required to award interest as fixed in the contract at a rate of Pk% per month from the date the debt was due— March 13, 1974 — until the date that payment is finally made. Furthermore, it argues that the trial court erred in finding the contract did not call for compound interest.
The relevant statute, D.C. Code 1973, § 15-108, reads, in pertinent part, as follows:
In an action ... to recover a liquidated debt on which interest is payable by contract or by law or usage the judgment for the plaintiff shall include interest on the principal debt from the time when it was due and payable, at the rate fixed by the contract, if any, until paid. [Emphasis added.]
This provision applies where the action is to recover a liquidated indebtedness, in contrast to D.C. Code 1973, § 15-109 providing interest on judgments for unliquidated breach of contract claims.
See Blustein v. Eugene Sobel Co.,
The only decision in the District of Columbia cited.to us as permitting an exception to the application of D.C. Code 1973, § 15-108 to a liquidated debt is
Powers v. Metropolitan Life Insurance Co.,
That does not end our inquiry into the applicability of the statute in this case, however. We must still determine (1) whether the debt owed Giant was liquidated; and (2) if so, what is the amount of the “principal debt” upon which interest is allowable.
If we consider Giant’s claim on its breach of contract action alone, the debt is certainly for a liquidated amount — the contract price. A question still arises, however, as to the meaning of the word “liquidated” in the statutory context. We must determine, in particular, whether Bender’s counterclaim, which the court expressly found to be unliq-uidated, takes Giant’s claim outside the scope of § 15-108. There are three general rules of law concerning the availability of interest where an unliquidated counterclaim or setoff is asserted against a liquidated claim. 8
One of these rules, which Bender urges us to apply here, has been stated as follows: “where the liquidated demand is subject to reduction by virtue of an unliquidated claim the balance due is deemed to be an unliqui-dated sum upon which interest is not recoverable.”
Hansen v. Covell,
The rule was applied in
Excelsior Terra Cotta Co. v. Harde,
Another case principally relied upon to support the application of this rule is
Jar-
*1300
dine Estates
v.
Donna Brook Corp.,
There is little precedent supporting this rule, however, and it appears to be a minority view. A great many courts have not considered that a liquidated claim for damages becomes converted into an unliquidat-ed debt where there is an unliquidated counterclaim or setoff.
See, e. g., Fluor Corp. v. United States ex rel. Mosher Steel Co.,
There are two other approaches: the “interest on the entire claim” rule and the “interest on the balance” rule.
11
Under the first of those approaches interest is calculated on the full amount of the liquidated claim; then, the defendant’s unliquidated counterclaim is subtracted from that amount to determine the final award.
See, e. g., Hunt Foods, Inc. v. Phillips,
We regard the decision of this court in Welch, supra, as influential but not controlling for reasons we will delineate. There, two actions were consolidated. In one action the Birds, owners of a residence, sued Welch, a plumbing contractor, for conversion of personal property and for defective performance of its contractual obligations. Welch sued for the balance due under the contract for labor and materials. The court said:
We are of the opinion that instead of two separate suits there should have been an original suit and a counterclaim thereto; or, at pretrial, the suit by Bird against Welch should have been aligned as a compulsory counterclaim in the suit by Welch against the Birds so that the issues of fact and instructions upon the law could have been more readily given to the jury with final direction to bring in a net verdict.
Welch, supra
at 739 n.7. The court also approved the award of interest to Welch on the amount found to be due it for its work, but ordered that the interest should only be computed on the net balance owed to Welch after deduction of damages due the Birds as an offset of Welch’s principal amount awarded. The case does not discuss the distinction between claims for liquidated and unliquidated damages. Nor does the court rely specifically on a statutory provision for the allowance of interest. Rather, it relies on the precedent of
Tendler v. Jaffe,
Cases from other jurisdictions which have applied the “interest on the balance” rule also generally recognize the validity of the “interest on the entire claim” rule, and set forth the following distinction as to when each is applicable:
Where the plaintiff’s demand is liquidated he is given interest on the full amount, by treating the defendant’s unliquidated demand as a discount and not as a payment, . . . [and this rule is] applicable in cases where the claim for deduction could not be said to be demandable at the time when the original liquidated claim became due, but was rather the proper subject of a counterclaim for damages than an offset in the nature of a payment.
Annot.,
We must now decide whether to (1) deny prejudgment interest by treating the principal debt as unliquidated under the “conversion of liquidated claim” rule, (2) award interest on the entire claim, or (3) allow interest on the net balance. In choosing between the three approaches, we remain cognizant of the purpose to be served
*1302
in awarding interest. It is generally viewed “as compensation allowed by law for the use or forebearance of money or as damages for its improper retention.”
Ralston Purina Co., supra
at 212;
see also Young
v.
Godbe,
The choice between the other two rules is more difficult, but we think that the law and equities favor application of the “interest on the net balance” approach in this case. The appropriate inquiries to be made appear to be two: (1) whether the “claim for deduction [due to the counterclaim or setoff] could ... be said to be demandable at the time when the original liquidated claim became due and thus, requiring interest on the balance”; 13 or (2) whether the breach of warranty claim was “the proper subject of a counterclaim for damages [rather] than an offset in the nature of a payment,” 14 requiring interest to be awarded on the entire claim.
Generally, the “interest on the entire claim” rule entitles the plaintiff to interest on the full amount of his claim when the counterclaim does not directly concern the plaintiff’s claim, that is, when the unliqui-dated counterclaim arises out of a collateral matter. Ralston Purina Co., supra at 211. Here, Bender’s unliquidated claim existed, and was demandable, long prior to the time when Giant’s liquidated claim became due. Furthermore, although styled as a counterclaim for damages and based on what the trial court found was a separate transaction (/. e., the 1968 contract), we think Bender’s claim was an offset in the nature of a payment rather than an independent matter unconnected with Giant’s claim. This is because the subject matter of both transactions involved carpeting for the eleventh and twelfth floors of the same building. Without Giant’s breach of the express warranty pertaining to the 1968 contract (the first transaction), the second transaction (the 1973 contract) would not have occurred. Bender paid Giant for five years of guaranteed carpeting performance and only received three years. Bender’s entitlement to the amount of its counterclaim, or setoff, is essentially based on the fact it had already paid Giant for two years of the guaranteed carpeting performance, which was subsequently provided by Giant’s installation of replacement carpeting pursuant to the 1973 contract. Additionally, during the entire contested interest period, Bender was obligated to Giant for the amount of the liquidated debt. Simultaneously, however, Giant was obligated to Bender in the amount of the smaller counterclaim. Thus Giant was really only deprived of the use of money to the extent of the difference be *1303 tween the two claims. See Ralston Purina Co., supra at 212-13.
Thus, we view Bender’s unliqui-dated counterclaim, under the particular facts of this case, as an offset in the nature of a payment on the 1973 contract. Consequently, Giant is now entitled to prejudgment interest on the difference between the amount of its liquidated claim ($40,139.92) and Bender’s unliquidated counterclaim— $20,731.50. 15 This leaves a total principal debt owed Giant of $19,408.42 plus interest. 16
The next question is at what rate should interest be awarded and whether the interest should be compounded. Here again we must look to the statute first. D.C. Code 1973, § 15-108 provides that “the judgment for the plaintiff shall include interest ... at the rate fixed by the contract, if any . . ..” Under the statute, therefore, the rate of interest agreed upon and fixed by the parties in the contract controls, rather than the statutory rate of interest specified in D.C. Code 1973, § 28-3302.
See Bethlehem Steel Co. v. Lykes Bros. Steamship,
Appellees argue, however, that the finance charge violates the revolving credit account provisions of the District of Columbia Consumer Credit Protection Act of 1971, 18 and should, therefore, be stricken from the contract. We agree that the revolving credit provisions apply here. However, those provisions, in our view, necessitate a limitation of the finance charge (to 1% per month on the balance exceeding $500) rather than an eradication under the facts of this case. D.C. Code 1973, § 28— 3702.
The purpose of the revolving credit provisions of the Act was to establish maximum credit service charge rates for revolving credit accounts including credit cards growing out of retail sales in the District of Columbia. See H.R.Rep.No.92 — 724, 92d Cong., 1st Sess. 6, 96-100 (1971). To effectuate this purpose, Congress authorized retail sellers to engage in arrangements with buyers whereby credit is extended in connection with the sale of goods and services on time, and limited accompanying monthly credit service charges to 1% on balances *1304 exceeding $500. 19 D.C. Code 1973, § 28-3702. Interestingly, the revolving credit provisions were enacted in response to creditor, not consumer pleas, to insure that credit extensions in connection with retail sales remained outside the usury laws. See Ralph J. Rohner, Holder in Due Course in Consumer Transaction: Requiem, Revival or Reformation, 60 Cornell L.Rev. 503, 539 (1975).
While the legislative history is scant, there is no indication that the revolving credit provisions were designed to reach consumption by a natural person while excluding purchases by a commercial entity. 20 Significantly, the provisions define a “buyer” as a person (including corporations, partnerships, association or any other group of persons however organized) who buys goods or obtains services from a seller pursuant to a retail credit sale and not principally for the purpose of resale. D.C. Code 1973, § 28-3701(4), (5). The statutory language appears broad enough to encompass the Giant-Bender transaction which was essentially a credit sale with Bender intending to use, not sell, the carpets.
The trial court specifically found that the December 3, 1973 contract 21 did not call for compound interest. Appellant does not argue that the trial court’s finding is “plainly wrong or without evidence to support it.” D.C. Code 1973, § 17-305(a). Rather, it argues that the statute and the contract require the award of compound interest, presumably as a matter of law. We cannot say the trial court erred. Prejudgment and judgment interest are ordinarily not compounded in the absence of contract provision. Dobbs, Remedies § 3.5 at 164 (1973). The statute refers specifically to awarding interest on the “principal debt.” We have just concluded that the principal debt is the net balance owing Giant. Furthermore, where the contract does not specifically require compound interest, we are reluctant to imply such a term absent a showing of agreement between the parties, particularly a term in aid of the party that drafted the writing. See 5 Corbin, Contracts § 1047 (1951); McCormick, Damages § 53 (1935).
There is no dispute as to when the interest commences — on March 13, 1974, thirty days after the debt’s maturity date, as specified by the 1973 contract. There is disagreement, however, as to how long that interest continues to be computed. Appellant relies on the statutory language again, *1305 which reads “the judgment for the plaintiff shall include interest on the principal debt from the time it was due and payable . until paid.” D.C. Code 1973, § 15-108 (emphasis added). Appellee contends that “[i]t would be inequitable to allow interest to run during the delay in payment occasioned by Plaintiff’s appeal.” 22 This argument is not persuasive because appellee could have, and perhaps should have, paid Giant the amount awarded by the trial court — $19,-408.42. 23 That would have prevented incurring any more interest on the principal debt pending our decision.
As a general rule, an adversary’s appeal does not, by itself, dispense with the formality of a tender to stop the running of interest.
See generally
Dobbs, Remedies,
supra
at 176-78; Annot., 4 A.L. R.3d 1221, 1234 (1965). Absent waiver or conduct estopping the creditor from claiming interest pending appeal, the creditor should not be penalized for seeking to increase the award in his favor, particularly where the debtor also appeals.
24
See
An-not.,
The trial court, having awarded no prejudgment interest, awarded Giant “interest at the rate provided by law from the date of judgment [January 31, 1977] . .” Although not specifically mentioned by the trial court this award was presumably made pursuant to D.C. Code 1973, § 15-109, which provides, in pertinent part, that “[i]n an action to recover damages for breach of contract the judgment shall allow interest on the amount for which it is rendered from the date of the judgment only.” Section 15 — 109 is inconsistent with Section 15-108 to the extent that it authorizes interest only on the judgment from the date of judgment, rather than on the principal amount due from the date due until the date paid. We think this inconsistency is due to the difference in applicability of the two provisions. Section 15-108 eliminates the traditional distinction between prejudgment interest and interest on the judgment itself in cases involving a liquidated debt where interest is payable by contract law, or usage.
See, e. g., Kiser v. Huge,
*1306
The next issue raised by appellant is whether the trial court correctly based breach of warranty damages on the cost of the replacement carpet, rather than on the cost of the original carpet. Under both statutory and decisional law the settled standard for recovery in a situation such as this is “the difference between the actual value of the article sold and what it would have been worth had it been as warranted . . . [plus] those damages which were the natural consequence and proximate result of . [the] conduct [of the party who breached the warranty].”
Meyers v. Antone,
D.C.App.,
We reverse the trial court’s determination that no prejudgment interest should be awarded and order that, on remand, the trial court enter judgment for Giant for the principal sum of $19,408.42 plus interest on that sum from March 3, 1974 until this judgment is satisfied.
Affirmed in part, reversed in part, and remanded for proceedings consistent with this opinion.
Notes
. We shall refer to the four defendants (appel-lees) collectively as Bender. These four are Jack Bender & Sons — in the business of owning, developing and managing commercial properties; Blake Construction Co., Inc. — also engaged in that business, managing in particu-¡ar a building at 1100 L Street, N.W.; and Morton A. Bender and Stanley S. Bender — both of whom were general partners in the 12th & L Limited Partnership, which owned and operated the 1100 L Street office building.
. Bender had previously purchased over two hundred thousand square yards of this type of carpet from Giant.
. Bender apparently had a new tenant, the Federal Maritime Commission, scheduled to occupy the eleventh and twelfth floors, and needed replacement carpeting quickly.
.This amounts to $16,056 (40% of $40,139.92, rounded off to the nearest dollar).
. See text, supra.
. In Powers the court correctly stated the rule that equitable considerations bear on whether interest should be allowed, in the absence of interest payable by contract, law or usagé.
. Furthermore, the trial court’s reliance on both 5 Corbin, Contracts §§ 1050-51 (1964), and
Southern New England Contracting Co. v. State,
.
See generally
Annot.,
. The defendant argued in
Hansen, supra,
. In that case the court said that “even though the existence of an unliquidated counterclaim or set-off necessarily puts the amount payable in doubt, it is well settled that it does not render the claim itself uncertain or deprive the claimant of the right to prejudgment interest.” Id.; footnote omitted.
. In
Ralston Purina Co. v. Parsons Feed & Farm Supply, Inc.,
.In its opinion in that case the Supreme Court said: “If a debt ought to be paid at a particular time, and is not, owing to the default of the debtor,-the creditor is entitled to interest from that time by way of compensation for the delay in payment.” Id.
. Annot.,
. Id.
. For a discussion of the propriety of the computation of damages on the counterclaim, see text infra.
. Appellees also argue that: (1) no interest is payable because an open account relationship existed between the parties (this issue is the subject of appellees’ cross-appeal); (2) the parties’ course of dealing shows that they never intended interest be paid. The trial court specifically found as a fact that the open account relationship had terminated some months prior to the December 1973 contract. On the record before us, we do not think that this finding was either clearly erroneous or without evidence to support it.
See
D.C. Code 1973, § 17-305(a);
Lee Washington, Inc. v. Washington Motor Truck Transportation Employees Health & Welfare Trust,
D.C.App.,
. For purposes of the usury laws, of course, a finance charge is not considered interest.
See,
e.
g., Kass v. Central Charge Service, Inc.,
D.C.App.,
. Pub.L.No.92-200, § 4, 85 Stat. 668 (1971), codifíed in D.C. Code 1973, § 28-3801-02.
.D.C. Code 1973, § 28-3701(1) defines “revolving credit account” as
an arrangement between a seller or financial institution and a buyer pursuant to which (A) the seller may permit the buyer to purchase goods or services on credit either from the seller or by use of a credit card or other device, whether issued by the seller or a financial institution, (B) the unpaid balances of amounts financed arising from purchases and the credit service and other appropriate charges are debited to an account, (C) a credit service charge if made is not precomputed but is computed on an outstanding unpaid balance of the buyer’s account from time to time, and (D) the buyer has the privilege of paying the balances in full or in installments. D.C. Code 1973, § 28-3701(2) defines “credit
service charge” as
the sum of (A) all charges payable directly or indirectly by the buyer and imposed directly or indirectly by the seller as an incident to the extension of credit, including any of the following types of charges which are applicable; time price differential, service, carrying or other charge, however denominated, premium or other charge for any guarantee or insurance protecting the seller against the buyer’s default or other credit loss; (B) charges incurred for investigating the collateral or credit-worthiness of the buyer or for commissions or brokerage for obtaining the credit, irrespective of the person to whom the charges are paid or payable, unless the seller had no notice of the charges when the credit was granted.
. The revolving credit provisions, in fact, are contained in a chapter separate from the consumer protections. See D.C. Code 1973, § 28-3801 et seq. Chapter 38 — Consumer Protections includes separate provisions for consumer credit sales.
. Although the trial court referred to the agreement of November 29, 1973, this was an apparently mistaken reference to the December 3, 1973 contract. The former document contained the identical finance charge language, but different prices.
. Brief for Appellee at 28 n. 13.
. This appeal in no way could have resulted in a lesser amount being awarded, as all of appellant’s arguments are directed to increasing the trial court’s award.
. The outcome of the creditor’s appeal may, however, determine whether interest runs from the trial court award or only from the date that an award modified on appeal is made effective. When a judgment creditor unsuccessfully seeks to increase his award, most courts would suspend the running of interest for the appeal period. In contrast, when an award for the creditor is modified on appeal, interest is generally allowed during the interim.
See
Annot.,
. In light of this finding we do not reach the issue of whether the trial court was plainly wrong in finding that the original carpet had cost $8.21 per square yard installed, rather than $7.31. Only if we had found Giant correct in its contention that the proper measure of damages was the price of the original carpeting would we need to decide that.
. The fact that the second carpet cost more does not, by itself, demonstrate superiority to the original carpet, had it been as warranted. The trial court implicitly found that the replacement was a reasonable one — i. e., it was of substantially the same style, grade and character as that for which Bender had originally contracted.
