About Us
Stone Mill Company is a full-service property and construction management firm built on trust, experience, and results. We manage multi-unit and commercial properties with a focus on maximizing performance while delivering unmatched service to both owners and tenants. Our team combines hands-on expertise in leasing, maintenance, construction, and compliance to offer a truly comprehensive solution. Whether we’re managing your property, developing a new asset, or overseeing a remodel, we operate with one goal in mind: to protect and grow your investment with care, clarity, and consistency. At Stone Mill, we don’t just manage—we lead with purpose.
Stone Mill Company is a full-service property and construction management firm built on trust, experience, and results. We manage multi-unit and commercial properties with a focus on maximizing performance while delivering unmatched service to both owners and tenants. Our team combines hands-on expertise in leasing, maintenance, construction, and compliance to offer a truly comprehensive solution. Whether we’re managing your property, developing a new asset, or overseeing a remodel, we operate with one goal in mind: to protect and grow your investment with care, clarity, and consistency. At Stone Mill, we don’t just manage—we lead with purpose.
What Makes Stone Mill Different
We operate with a purpose: to simplify property ownership while maximizing asset performance.
-
Full-Service Management & Construction
-
Owner-Focused Strategies
-
Responsive, Respectful Team Culture
-
Deep Market Knowledge
Full-Service Management & Construction
Owner-Focused Strategies
Responsive, Respectful Team Culture
Deep Market Knowledge
-
Full-Service Management & Construction
-
Owner-Focused Strategies
-
Responsive, Respectful Team Culture
-
Deep Market Knowledge
.jpeg)
People First, Always
Stone Mill was founded on one simple belief: when you treat residents, owners, and vendors with respect and clarity, everything else follows. We're here to raise the standard.
The Builders Behind the Brand
Nicholas Koll Kerstner
Nicholas Koll Kerstner is a Founding Member of Stone Mill Company while also serving as a Principal Member of Grankol Enterprises Inc. Which manages over $450 million worth of real estate assets.
He received his B.S. in Economic and Reginal Development from the University of Arizona in 2012. After graduating he joined his grandfather and father working for Grankol Enterprises.
In 2016 he was promoted to executive vice president of Grankol with the focus on expanding the business into new opportunities. With this new focus he oversaw the purchase, entitlement and completion of a semi-custom track home development in Costa Mesa, CA.
In 2017 Grankol began to renovate and 1031 exchange multiple of the multifamily and industrial properties. Successfully completing over $250 million in transactions. Growing the net worth of the family by over 250%.
In 2018, Nick spear headed the initiative to expand outside of California. His team successfully purchased, entitled and are developing 3 new multifamily communities in Phoenix, AZ. Elevation townhomes, a 48 townhome style community was completed in August 2024, Canyon Townhomes a 57 townhome style community broke ground in September 2024 and a third higher density project scheduled for 2026.
Nick founded Stone Mill Company in 2025 with the goal of managing other Real Estate portfolios not owned by Grankol Enterprises. Maintaining a focus on top tier construction and property management.
Nicholas “Nick” Anderson
Nicholas “Nick” Anderson is a Founding Member and current Operations Manager of Stone Mill Company. As a sixth-generation Orange County native, Nick blends deep regional understanding with more than 15 years of leadership experience in property and construction operations.
He oversees day-to-day management of approximately 500 residential units and 9 warehouses across a family-owned portfolio—handling everything from team coordination and tenant relations to budgeting and on-the-ground execution.
Nick holds a Bachelor's degree in Business Management and is passionate about efficient systems, high-quality craftsmanship, and delivering outstanding service. Outside of his professional role, he enjoys gardening, traveling, and spending time with his three kids—his favorite (and most energetic) team.