Adolf and Ida Krueger contracted with Pisani Construction, Inc., to erect a metal building as an addition to an existing structure. The two structures were to share a common wall, and the frames and panel heights of the new building were to match those of the existing structure. Shortly before completion of the project, however, it was apparent that the roofline of the new building was approximately three inches higher than that of the existing structure. Pisani modified the ridge caps of the buildings to blend the rooflines. The discrepancy had other consequences, however, including misalignment of the gutters and windows of the two buildings, which resulted in an icing problem in the winter. The Kruegers occupied the new structure but refused to make the last payment under the contract. Pisani fileda suit in a Connecticut state court to collect. Did Pisani substantially perform its obligations? Should the Kruegersbe ordered to pay? Why or why not?