This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
If the promisor has made default in performance with respect to the time thereof, and the promisee subsequently permits or urges him to continue performance,1 or accepts performance thereafter,2 or accepts payments made in performance,3 or otherwise treats such contract as still in force,4 such breach is waived. Thus permitting a contractor to complete a building contract after the time fixed by such contract for performance waives the right to treat such default as discharge.5 Breach of a contract to make a designated payment at a designated time, as a means of securing the release of a lot from a trust deed, is waived by the payee's recognizing such contract as still existing.6 Waiver in such cases is often clearer where the delay has been requested by the promisee,7 or where he has authorized the same in advance,8 or led the adversary party to believe that strict performance would not be insisted on,9 or where modifications of the contract requested by him have caused such delay in performance.10 Thus a delay in suing on an insurance policy for a period greater than that fixed by such policy, does not prevent recovery if made at the suggestion of an agent of the insurer.11 Thus, if the collector for a telephone company suggests a delay in the payment of rental for a telephone, the telephone company cannot thereafter use such, delay as a ground for forfeiture of the contract.12 So under a building contract a contractor is excused for delay which is caused by a change in the plans13 or material14 ordered by the owner. Even if the contract provides that orders for extra work must be in writing, delay caused by the contractor's complying with oral orders of the owner is excused.15 On the other hand he may decline to perform after the plans are changed unless the architects put extra allowance for changes in writing as required by the contract; and he may decline to act under oral allowance.16 However, if the promisor has specifically agreed to take all risks, he is not allowed to show that improper performance on the part of the promisee caused breach by the promisor.17 Under a subsequent agreement to extend the time of performance to a certain date, there is no waiver of the right to treat the contract as discharged by failure to perforin at that date.18
1 Pennington v. Howland, 21 R. I. 65; 79 Am. St. Rep. 774; 41 Atl. 891.
2Whyte v. Rosenerantz, 123 Cal. 634; 69 Am. St. Rep. 90; 56 Pac. 436.
3 Wind v. Iler, 93 la. 316; 27 L. R. A. 219; 61 N. W. 1001.
4Genni v. Hahn, 82 Wis. 90; 51 N. W. 1096.
5 Cream City Glass Co. v. Fried-lander, 84 Wis. 53; 36 Am. St. Rep. 895; 21 L. R. A. 135; 54 N. W. 28.
1German Savings Institute v. ■ Machine Co., 70 Fed. 146; 17 C. C. A. 34; Andrews v. Tucker, 127 Ala. 602; 29 So. 34; McArthur Brothers v. Whitney, 202 I11. 527; 67 N. E. 163; Prentiss v. Lyons, 105 La. 382; 29 So. 944; Orem v. Keelty, 85
Md. 337; 36 Atl. 1030; Bean v. Bunker, 68 Vt. 72; 33 Atl. 1068.
2 Jeffrey Mfg. Co. v. Iron Co., 93 Fed. 408; Neosho City Water Co. v. Neosho, 136 Mo. 498; 38 S. W. 89.
3 Davis v. Robert, 89 Ala. 402; 18 Am. St. Rep. 126; 8 So. 114; Mack v. Dailey, 67 Vt. 90; 30 Atl. 686.
4 Contract for sale of realty after default by vendee. Monson v. Brag-don, 159 I11. 61; 42 N. E. 383; Moore's Estate, 191 Pa. St. 600; 43 Atl. 474. After default by vendor. Garbes v. Roberts, 98 Wis. 173; 73 N. W. 995. Contract for the sale of stock. Jones v. Brown, 171 Mass. 318; 50 N. E. 648. Contract for delivering bonds to be held as collateral security. Herr v. Sullivan, 25 Colo. 190; 54 Pac. 637. Contract for constructing streets after default by the contractor. Orem v. Keelty, 85 Md. 337; 36 Atl. 1030.
5 Barnard v. McLeod, 114 Mich. 73; 72 N. W. 24; Wortman v. Ry., 22 Mont. 266; 56 Pac. 316; Linch v. Elevator Co., 80 Tex. 23; 15 S. W. 208; Long v. Pierce County, 22 Wash. 330; 61 Pac. 142; Brodek v. Farnum, 11 Wash. 565; 40 Pac. 189.
6 Lapsley v. Howard, 119 Mo. 489; 24 S. W. 1020.
7 Hinckley v. Steel Co., 121 U. S. 264; Barnes v. Stacy, 79 Wis. 55; 48 N. W. 53.
8 Emerson v. Slater, 22 How. (U. S.) 28; Watson v. White, 152 I11. 364; 38 N. E. 902; Loveridge v. Shurtz, I11 Mich. 618; 70 N. W. 132; Clark v. Bache, 186 Pa. St. 343; 40 Atl. 484; Atlantic, etc., Ry. v. Construction Co., 98 Va. 503; 37 S. E. 13.
9 Lessell v. Goodman, 97 Ia. 681; 59 Am. St. Rep. 432; 66 N. W. 917.
10 Cornish v. Suydam, 99 Ala, 620; 13 So. 118; Davis v. Badders 95 Ala. 348; 10 So. 422.