Simplifying the Real Estate Experience in Springfield, Illinois At Core 3, we make property management easy for both residents and owners. As a third-party management company, we don't own the properties we manage, but we treat them like our own. From marketing vacancies and screening tenants to handling maintenance and day-to-day operations, we take care of the details so you don't have to. Whether it's an apartment, townhouse, or single-family home, Core 3 delivers straightforward, dependable service that simplifies your real estate experience.