Brothers 59 Construction delivers accessory dwelling unit in Franktown — open meadow and oak parcels east of Castle Rock. Typical project range $1M–$5M; acreage custom builds and ranch-style residences. 5.0/5 rating across 19 verified Google reviews.
| Tier | Investment Range | What's Included |
|---|---|---|
| Refined | $350,000–$600,000 | 600–900 sq ft detached guest house with full kitchen, bath, and finishes matched to the main home |
| Signature | $600,000–$1,100,000 | 1,000–1,500 sq ft ADU with vaulted living space, high-end kitchen, garage bay, and independent utilities |
| Architectural | $1,100,000–$2,000,000+ | 1,500+ sq ft custom guest residence with premium millwork, luxury baths, smart systems, and site-integrated architecture |
Where the investment goes: Labor & trades 42–55% · Materials & fixtures 30–42% · Design, permits & mgmt 12–20%.
ADUs carry a full house's systems on a small footprint, so per-square-foot costs run high—foundations, separate utility connections, and septic capacity (common on Douglas County acreage lots) are major cost centers. Zoning is the biggest variable: Douglas County limits ADU size and requires it to be subordinate to the primary residence, and well/septic permitting through Tri-County Health can add months. Matching the main home's luxury finish level and any required fire-sprinkler systems push the upper tiers.
Detached and attached ADUs from permit-set through CO: foundations, framing, full MEP, kitchen, bath, and finish package.
Douglas County ADU permitting, utility separation, and code-compliant egress, fire-rating, and energy assemblies.
Marvin, Sub-Zero/Wolf compact, Miele, Bosch
Active across Russellville Ranch, Bannockburn, Fox Hill and surrounding Franktown neighborhoods, with HOA-compliant design review packages prepared to each ARC standard.
Brothers 59 Construction publishes monthly Douglas County permit reports sourced from official county records.
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Yes, but with restrictions—size is typically capped relative to the main home, only one ADU per lot is permitted in most zones, and rural lots must verify well and septic capacity before approval; we handle the full zoning and permitting review up front.
Often yes on unincorporated acreage; either your existing system must be re-engineered for the added load or a new field installed, which can add $30,000–$75,000 and requires Tri-County Health approval.
Long-term rental of a permitted ADU is generally allowed, but short-term rental rules vary by community and HOA—we recommend confirming current Douglas County and covenant restrictions during planning.
Phone: 303-434-7658 · Email: michaelglivar1@gmail.com