Home renovations almost always surpass the initial budget primarily because of unexpected issues that arise once the work begins. Often, behind-the-scene problems like electrical wiring or plumbing issues can ramp up costs quickly. Additionally, changes in the plan mid-project or upgrades in materials can also inflate the budget. The tendency to underestimate labor costs is another factor that leads to overshooting the budget. Lastly, delays can result in increased labor costs and price hikes in materials, making the renovation more expensive than initially planned.