Compact Garage ADU Addition
Project Overview
The homeowner needed a cost-effective way to add rental income and flexible living space without overbuilding the site. Prenvalley Builders designed and built a highly efficient garage ADU, navigating tight space constraints while prioritizing durability, comfort, and long-term performance. What makes this project special is how much functionality and livability was achieved within a streamlined footprint.
Project Details
Size: 288 sq ft
Location: Denver, Colorado
Architectural Design: Prenvalley Builders
Our Approach
Prenvalley Builders approached this garage ADU with a focus on efficiency, durability, and long-term value. By carefully balancing layout, material selection, and constructability, the team delivered a high-performing space that supports rental use and everyday comfort. The result is a thoughtful design-build solution tailored to the site and the client’s goals.
Project Highlights
Converted an existing garage into a functional ADU
Maximized space with an efficient open layout
Installed a durable, rental-ready kitchenette
Added a private bedroom and full bathroom
Integrated energy-efficient systems
Delivered a cost-effective rental solutio
Results
The completed garage ADU provides a comfortable, efficient living space that supports both rental income and flexible use for the homeowner. Thoughtful planning and durable finishes ensure the space performs well over time. The result is a streamlined addition that adds real value without unnecessary complexity.
Project Goals
Create a cost-effective ADU for rental income
Maximize livability within a compact footprint
Improve long-term durability and performance
Support flexible use for guests or family
Add value without overbuilding the site
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.
