Landmark District Two-Story ADU + Garage
Project Overview (Under Construction)
This Denver ADU was designed and built to add flexible living space while respecting the character of an established urban neighborhood. The project required careful planning due to landmark design considerations and challenging soil conditions, making coordination and execution especially critical. What sets this build apart is the thoughtful balance between structure, context, and long-term performance.
Project Details
Size: 1160 sq ft
Location: Denver, Colorado
Architectural Design: F9 Productions
Our Approach
Prenvalley Builders approached this ADU with a design-build strategy focused on early coordination, constructability, and long-term performance. Working within a landmark context and difficult soil conditions required close collaboration between design, engineering, and construction from day one. The result is a well-planned build that balances structural integrity, efficiency, and neighborhood compatibility.
Project Highlights
Built a two-story ADU on a tight urban lot
Navigated landmark design requirements
Engineered a foundation for sandy soil conditions
Installed deep helical piers for structural support
Coordinated utilities and structure in limited access conditions
Results
The completed ADU delivers durable, well-integrated living space that fits naturally within its urban context. Careful planning and structural solutions addressed site constraints while supporting long-term performance. The result is a highly functional Accessory Dwelling Unit built to last and designed with intention.
Project Goals
Add functional, flexible living space through a thoughtfully built ADU
Build within a landmark context while maintaining neighborhood compatibility
Address challenging soil conditions with long-term structural solutions
Maximize usability on a constrained urban lot
Common Questions about Accessory Dwelling Units
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This varies quite a bit throughout Colorado based on your city’s specific zoning guidelines. Our team are experts with zoning rules throughout the state and can provide you with a detailed breakdown of what’s possible.
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We usually get asked how much an ADU costs per square foot but this is the hardest metric for an ADU since the cost per square foot parameter can vary drastically based on the size. This is due to the fact that ADUs are small compared to normal homes and the cost per sq. ft. can vary dramatically due to the economy of scale factor. Also, most of the ADUs we build have unfinished garages which complicates that metric even further. We’ve found that ADUs in Denver can vary on average from $250k to $450k based on size, finish level, and site constraints.
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As of right now the average ROI ranges from 4 to 7 years until you begin seeing a net positive on your ADU investment which is based short term renting the space over that time. The problem with ADUs in Colorado is that there aren’t many comparables when appraisers are valuing these spaces so they are typically appraised at a lower value than they were built for. As more ADUs are built and sold with their primary homes, these numbers will improve so this ROI is very much temporary. As of now, ADUs are considered a long term investment and are definitely worth the consideration if you’re looking to hold onto your home for the long run.
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In our experience thus far, the scale of an ADU hasn’t been proven to be built better or more cost effective in a modular format. The modular ADU on paper seems like a great idea but all of the companies we’ve seen provide them are at a comparable price point if not higher and quality issues can occur due to manufacturing, delivery, and assembly issues. We view ADUs as custom small homes that need to be built with care and craftsmanship which can easily be lost in a mass manufacturing process.
