Badung Regency as one of the regencies in Bali Province that has a construction service package in Badung Regency experienced a significant increase in 2023 as many as 128 project data. Project development always continues to increase due to demand by project owners, which occurs during the project period causing construction changes. These changes result in inconsistencies with the initial plan. Changes occur very often, so they will have an impact on increasing costs, late project completion, and also building quality that does not comply with the quality plan. The impact of contract changes occurs on costs because additional costs have implications for increasing work volume. The description of the work of implementing a building construction project is very complex, so it is rare in a building construction project that there is no change in the contract until the project is completed. In this study, a deductive approach will be carried out with a quantitative method. The sampling technique used is non-probability sampling with the convenience sampling method. There are 5 (five) factors that form contract changes, 5 (five) factors form cost performance, 6 (six) factors form time performance, 5 (five) factors form quality performance. The relationship model describes the direct relationship between contract changes and project performance using the second order on Smart PLS. Contract changes have a significant relationship to project performance, where when a contract change occurs it will directly affect project performance.