Case 11: promises to do more than was agreed; promises to waive a condition

The promise in Case 11(b) resembles a renunciation (kwijtschelding). In the new code, a renunciation is a contract, albeit with a specific rule which makes the acceptance of a gratuitous renunciation easy (art. 6:160 of the Civil Code).5 Nevertheless, a renunciation involves the extinction of an obligation, and one cannot really speak of one in this case.

If the promisor did not intend his promise to be legally binding, it might matter if Realty had already advertised the glareproof windows, or Contractor had already covered over portions of the building the architect would have needed to inspect, before the promisor threatened not to keep his promise. These facts may be relevant for establishing whether he is bound on the basis of art. 3:35 of the Civil Code (reliance principle). It provides that a party is bound, not only to what he intended, but to what the other party could reasonably think he meant.

Moreover, because of these facts, the promisor may also be estopped from claiming that he is not bound (venire contra factum proprium) under art. 6:2(2).

spain

As in Case 9, since the promises modify a previous contractual obligation, their enforceability depends on whether they qualify as novations. Novations are mentioned in art. 1156 of the Civil Code and governed by arts. 1203–13. A novation requires animus novandi.6 This requirement means that a party must express his will to replace one obligation with another or to modify an existing obligation.

In addition, following art. 1203 of the Civil Code, a novation must modify an obligation, which means that the novation must change its object or conditions, or the debtor or creditor. As we saw in discussing Case 9, a mere change in the amount owed has been thought to be insufficient. Nevertheless, Contractor’s modification of its obligation by promising to install glareproof quality in windows is enforceable as a novation that makes an objective modification. It changes the object of the prior obligation: one thing (lower quality windows) is replaced with another (glareproof ones).7 Realty’s modification of its obligation by promising to

5Article 6:160 of the Civil Code: ‘(1) An obligation is extinguished by a contract between creditor and debtor whereby the creditor renounces his claim. (2) An offer to renounce gratuitously, addressed by the creditor to the debtor, is deemed accepted when it has

come to the attention of the debtor and he has not rejected it without delay.’

6 Castán Tobeñas, Derecho civil, vol. III, 438; Díez Picazo, Fundamentos de derecho, vol. II, 796. 7 See Castán Tobeñas, Derecho civil, vol. III, 441.

258 the enforceabilit y of promises

pay without an architect’s certificate is also enforceable as a novation of conditions of the obligation.8 It replaces one conditional obligation (paying if the architect approves) with an unconditional obligation (paying).

Since the novations establish new contractual obligations, it does not matter whether or not Contractor had covered portions of the building or Realty had advertised the glareproof windows before the other party refused to fulfil its obligations as modified.

It also does not matter that the novations may increase the burden of the contract to one of the parties without any increase in compensation. In one decision of the Tribunal Supremo9 a tenant rented a shop and then received the landlady’s permission to modify the lease so as to permit installation of a chimney. When the chimney needed repairs, the landlady refused to pay on the grounds that she should not have to do so for something that was not included in the lease in the first place. The Court held that she must make the repairs because there had been a ‘transformation of the space from one for mercantile use into one for mercantile and industrial use; which constitutes an essential modification of the primitive obligation and, hence, a novation’. The landlady was therefore required to make repairs by art. 107 of the Law on Urban Leasing (Ley de Arrendamientos Urbanos) and art. 1554(3) of the Civil Code.

portugal

The promise of Contractor is binding whether or not Realty had already advertised the glareproof windows. The promise of Realty is not binding. However, the fact that Contractor had already covered over portions of the building the architect would have needed to inspect can be a cause for frustration of the right of inspection without liability for Contractor.

The contract here is one to do a job (contrato de empreitada). As mentioned in Case 9, it is possible for both parties to modify any contract by agreement (art. 406(1) of the Civil Code). Therefore, if Realty accepts the promise of Contractor, Contractor would be obligated to install more expensive glareproof windows whether or not Realty relies on that promise.

Nevertheless, Realty’s promise to pay Contractor without an architect’s certificate is not binding because it is illegal. The completion of work done under a contract to do a job must always be verified by an expert (art. 1218 of the Civil Code). The right of inspection can be exercised by the party

8 See Puig Brutau, Fundamentos de derecho civil, vol. I-2, 467 and Díez Picazo, Fundamentos de