## Facts

- A contractor and an owner executed a written contract (Jan. 20, 1914) for construction of a moving-picture theatre in Philadelphia under architects’ plans and direction.
- The contract price was $7,750, later increased by $1,000 for an enlargement (total $8,750).
- The contract stated that payments were due “wholly upon certificates of the architect,” including progress payments and final payment upon a certificate of satisfactory completion.
- The completion date was set and later extended by addendum.
- During construction, the owner paid the contractor $6,000 in installments, almost always without requesting or requiring the architect’s written certificates; a certificate was requested only once.
- The contractor sued in assumpsit for the unpaid balance ($2,750) plus interest.
- The owner defended on grounds of deviations from plans, inferior materials and workmanship, late completion, and a claimed offset/penalty for delay.
- The architects testified that the building was substantially completed and that certificates were not issued because no one asked for them, not because the work was unsatisfactory.

## Issues

1. Whether the contractor could recover the contract balance when the contract required the architect’s certificates as a condition of payment and no final certificate had been issued.
2. Whether the owner’s repeated payments and failure to demand certificates constituted a waiver excusing strict compliance with the certificate condition.
3. Whether alleged defects, deviations, and delay barred recovery as a matter of law or were factual questions for the jury with possible deductions from the contract price.

## Decision

- The Supreme Court of Pennsylvania affirmed a judgment for the contractor.
- The architect-certificate requirement, included for the owner’s benefit, could be waived, and the evidence supported a finding that the owner waived strict insistence on certificates by paying without them and not requesting them.
- The absence of a formal final certificate did not bar recovery where the architect was satisfied and non-issuance resulted from the parties’ course of dealing rather than dissatisfaction.
- Claims of defects, deviations, and delay were properly submitted to the jury, and the evidence supported the verdict.
- The jury’s award of less than the full claimed balance supported the view that any proven shortcomings were accounted for through a reduced recovery.

## Legal Principles

- A contractual condition precedent inserted primarily for one party’s protection may be waived by that party’s conduct.
- Repeated acceptance of performance and payment without insisting on an architect-certificate requirement can constitute implied waiver, preventing later enforcement of the condition to defeat payment.
- In construction contracts, substantial performance may support recovery of the contract price, subject to deductions for proven defects or delay.
- Whether performance is substantial and what deductions, if any, are warranted are commonly jury questions when the evidence is disputed.

## Conclusion

The court held that an owner who routinely paid without demanding architect certificates waived the certificate condition and could not use the absence of a final certificate to bar payment; disputes over workmanship, deviations, and delay were for the jury, which could award the balance less appropriate deductions.


McKenna v. Vernon, 258 Pa. 18, 101 A. 919 (Pa. 1917)