In Foust v. Hanson, 612 S.W.2d 251, 253 (Tex. Civ. App.--Beaumont 1981, no writ), the defendant agreed to construct, and the plaintiffs agreed to purchase, a house to be completed on or before October 1, but it was not completed until December. 612 S.W.2d at 252. The contract required the plaintiffs to obtain a mortgage loan for thirty years at the prevailing rate. Id. at 254. The commitment obtained by the plaintiffs expired on October 4, and the plaintiffs obtained another commitment at a higher interest rate. Id. The plaintiffs produced evidence of the difference in the monthly mortgage rate for the life of the loan due to the higher interest rate, and court of appeals affirmed the award. Id.