Walk two lots in Macanta or Crystal Valley and you'll see the same builders, the same rooflines, the same trail stubs waiting to connect to the next phase. What you won't see, because it's baked into the price before you ever tour the model home, is that the two floor plans next to each other can now carry meaningfully different town fees attached to the water tap alone. One is 3,600 square feet. One is 5,800 square feet. As of this summer, that difference is no longer incidental to what the builder charges. It's the whole point of how Castle Rock calculates the bill.
For years, new-construction buyers in Castle Rock treated development fees as a fixed cost of entry, a number the builder rolled into the price and nobody negotiated. That assumption just stopped being true.
The Fee Everyone Assumed Was Fixed
Every new single-family home built in Castle Rock pays a Renewable Water Resource Fee and a System Development Fee before it can connect to the town's water system. These aren't small. Morgan Cullen of the Home Builders Association of Metro Denver told reporters that development-related costs on a new Castle Rock home can top $100,000, roughly 15 percent of the home's final price, and that Castle Rock carries the highest impact fees of any local government in the Denver metro area.
Until this year, that number was calculated the same rough way for most single-family homes regardless of how big they were. A home's fee depended more on lot size, meter size, and fixture counts than on how much house actually sat on the lot. Two buyers could end up paying close to the same development fee whether they built a starter floor plan or a five-bedroom estate.
That flat-ish structure is gone.
What the Town Actually Changed
In April 2026, the Castle Rock Town Council approved a new methodology for calculating water, water resource, and wastewater system development fees on new single-family homes, moving from a fixture-based approach to a tiered structure keyed directly to finished square footage. The change followed a months-long study Castle Rock Water ran with an outside consultant, looking at actual water use across roughly 750 homes built between 2023 and 2025.
Mark Marlowe, director of Castle Rock Water, explained the reasoning behind the shift plainly during the council process.
"We want to make sure that we're charging the right amount for these system development fees, both for our existing customers, our future customers, the developers and home builders as well."
The town set a benchmark it calls the Single Family Equivalent, defined as the 75th percentile of home size built since 2023, which lands between 5,500 and 6,000 square feet. Homes smaller than that benchmark now pay lower system development fees. Homes larger than it pay more, scaled to their footage. Mayor Jason Gray framed the intent around affordability directly, saying the change could encourage builders toward smaller homes and help first-time buyers get into the market more easily.
Why Square Footage, and Why Now
The town's own data explains the timing. Castle Rock passed its ColoradoScape ordinance in 2022, restricting turf in front yards to cut outdoor irrigation demand. The 2023-2025 study found that ordinance worked well enough that yard size and irrigation habits no longer predicted a home's water use as reliably as its finished square footage did. Homes between 1,500 and 1,999 square feet averaged about 70 gallons a day. Homes between 5,500 and 5,999 square feet averaged about 167 gallons a day. Homes between 7,000 and 7,499 square feet climbed to roughly 185 gallons a day. The overall average across every home in the study sat around 152 gallons a day.
Marlowe connected that data directly to future infrastructure planning: "The fact that the water use is going down will have an equal benefit on the amount of infrastructure, the size of infrastructure, the timing of infrastructure." He added that newer homes simply aren't adding the peak demand the system saw in past growth cycles, which is the argument the town used to justify shrinking total system development fee revenue by close to 10 percent, an estimated $4 million reduction in the near term according to reporting in the Denver Gazette.
What This Means in Dollars, Not Just Policy
For a buyer comparing floor plans within the same Castle Rock subdivision, this is no longer background noise. If you're looking at a smaller plan in Sapphire Pointe or a compact layout in Montaine, you're now shopping into a fee structure the town built specifically to reward that choice. If you're eyeing a larger plan closer to or above the 5,500 to 6,000 square foot benchmark, whether that's a bigger build in Crystal Valley or one of the larger David Weekley, Toll Brothers, or Taylor Morrison floor plans in Macanta, you're on the paying end of the same recalibration.
This matters more right now than it might have two years ago. Castle Rock's median sale price sat near $650,000 over the three months ending in June 2026, down slightly year over year, with homes averaging about 26 days on market, according to Redfin's tracking of the local market. In a market that's cooled from its tightest years, the fee attached to a specific floor plan is one of the few costs a buyer can actually see coming and plan around before signing a builder contract, rather than negotiating after the fact.
One detail worth knowing before you fall in love with a floor plan: Marlowe clarified that when the town calculates square footage for this fee, it counts unfinished basements, because the town has to account for the space eventually being finished. A buyer who plans to leave the basement unfinished for now doesn't get a lower fee for that choice. The fee follows the home's built potential, not its current finish level.
It's also worth being precise about who this touches. The revised methodology applies only to single-family homes served by a standard quarter-inch meter. Multifamily, commercial, and larger-meter customers continue under the fee schedule that took effect January 1, 2026. And the change is a one-time development charge tied to the building permit, not an adjustment to what existing Castle Rock homeowners pay on their monthly water bill. A town spokesperson was explicit that this doesn't change ongoing utility costs for people already living in Castle Rock.
What to Actually Do With This If You're Shopping New Construction
A few practical moves for anyone touring builder models in Castle Rock this fall:
- Ask the builder or sales office directly what the current system development fee and renewable water resource fee are for the specific floor plan and finished square footage you're considering, not a general number for the community.
- If you're comparing two plans in the same subdivision, factor the fee difference into your total cost comparison the same way you'd factor in a larger lot premium or an upgraded elevation.
- If you're deciding whether to finish the basement now or later, know that waiting doesn't lower your development fee. The space counts either way.
- If you're weighing new construction against a resale home in an established Castle Rock neighborhood, remember that resale purchases don't carry this fee at all. It only applies at the point of new construction.
A Few Questions Worth Asking Before You Sign
Does this fee change affect resale homes in Castle Rock? No. It applies only to new single-family construction connecting to the town's water system for the first time, not to homes already built and changing hands.
Will this raise my monthly water bill if I already live in Castle Rock? No. This is a one-time development fee tied to new construction permits. It doesn't change ongoing utility rates for current residents.
Does this apply if I'm building in the Village at Castle Pines or unincorporated Douglas County? No. This is specific to the Town of Castle Rock's own water utility. Communities served by separate water and sanitation districts operate under their own fee structures.
New construction fee math in Castle Rock isn't the kind of detail most buyers think to ask about until they're deep into a builder contract, but it's exactly the kind of thing that changes what a floor plan actually costs once every line item is on the table. If you're comparing plans, sizes, or subdivisions and want a clearer read on what a specific home would carry before you commit, Borremans Properties can walk through the numbers with you alongside everything else that goes into a Castle Rock purchase.
Andrew Borremans, Borremans Properties
