Building software is a crucial task to compile, test, and deploy software systems while continuously ensuring some quality assurance of a project. As software is more and more configurable, building multiple configurations is a stressing need, yet, costly and challenging to instrument. The current state of practice is to build independently (a.k.a. clean build) a software for a subset of configurations. While incremental build has been considered for software evolution and relatively small modifications of the source code, it has not been surprisingly investigated for software configurations. In this first novel exploratory study, we investigate the benefits and limits to incrementally build software configurations, instead of always clean building them. By using five real-life configurable systems as subjects, we explore whether incremental build works, outperforms a sequence of clean builds, is correct w.r.t. clean build, and can be used to find an optimal ordering for building configurations. Our results showed that incremental build is feasible in 100% of the time in four subjects and in 78% of the times in one subject. In average, 88.5% of the configurations could be built faster with incremental built while also finding several alternative faster incremental builds. However, only 60% of faster incremental builds are correct. Still, when considering those correct incremental builds with clean builds, we could always find an optimal order that is faster than just a collection of clean builds with a gain up to 11.76%.