What You Need to Know About Accessory Dwelling Units (ADUs)

Accessory Dwelling Units, or ADUs, are small, secondary homes that share the same lot as a primary residence. These versatile structures can be anything from a backyard cottage or basement apartment to the increasingly popular pop-top garage. They offer homeowners a chance to create extra living space for family members, generate rental income, or simply increase their property value. If you’ve been following housing trends in Colorado, you may already know that House Bill 24-1152, passed in 2024, has set the stage for major changes. This legislation requires cities to loosen restrictions on ADUs by updating their zoning codes. Aurora has already begun shifting gears to comply with the state’s new law, which means now might be the perfect time to consider adding an ADU to your property.
Whether you’re simply exploring your options or you’re ready to draw up blueprints, here’s what you need to know about ADU construction and the challenges that come with it.

How House Bill 24-1152 Impacts ADUs in Aurora
House Bill 24-1152 was designed to address the housing crunch in Colorado. It mandates that municipalities across the state, including Aurora, adjust their zoning regulations to make it easier for homeowners to build ADUs. The city of Aurora is actively updating its zoning code to align with the bill, allowing residents to legally add secondary dwellings where such projects were previously prohibited.
However, while the new law creates pathways for ADU construction, it doesn’t override every zoning rule. Key property-specific regulations like setbacks, easements, and light step-back requirements still apply. These factors can influence the design and feasibility of your project. Before you get too far into the planning process, it’s crucial to consult a local architect or zoning expert to ensure compliance with these rules.

Pop-Top Garage ADUs: What You Need to Know
One of the most common ADU styles in Denver is the pop-top garage ADU. This involves removing the roof of an existing garage and adding a second story to create a livable space. While this approach can be a creative solution, it’s important to consider the potential challenges.
Older garages, in particular, often have shallower foundations or inadequate insulation that might not meet modern building codes. Even though the new legislation allows for these types of additions, they still need to pass inspections and adhere to current construction standards. If your garage lacks a strong foundation, you may have to invest in costly structural upgrades before proceeding.

Managing Utility Connections for an ADU
One of the advantages of building an ADU is the possibility of sharing utilities with your main house. This can significantly lower upfront costs. For example, instead of installing a brand-new electrical service for your ADU, you may be able to run a sub-panel from your existing system. Likewise, you might connect the ADU to your home’s water and waste lines, avoiding the high fees often charged by local utility companies for new hookups.
That said, there are potential roadblocks. While many homes were built with extra electrical capacity, it’s essential to have an engineer assess your system to ensure it can handle the additional load. Modern energy-saving features like solar panels and efficient appliances may leave you with wiggle room, but careful planning is needed to make the most out of your existing setup.

​Calculating the Cost of Building an ADU
The cost of building an ADU tends to be higher per square foot compared to larger construction projects. Why? It boils down to supply and demand for labor. Even though ADUs are small, you’ll still need to hire multiple subcontractors, including electricians, plumbers, and framers. Many contractors have project minimums, meaning they won’t take on jobs under a certain dollar amount. These thresholds can quickly add up, even for modestly sized ADUs.
On top of that, the surge of interest in ADUs following the passage of House Bill 24-1152 has attracted a mix of experienced and inexperienced contractors. To protect your investment, it’s smart to thoroughly vet any contractors you’re thinking of hiring. Look for professionals with a solid track record, proper licensing, and financial stability. Setting up clear contract terms and payment schedules can also help keep your project on track.

​Flexibility Is Key When Planning Your ADU
If you’re looking for inspiration for your ADU, you might be tempted by pre-designed plans found online. While these stock plans can provide a great starting point, modifications will likely be necessary to fit your property’s unique characteristics and comply with zoning rules. For example, a sloped lot or specific setback requirement could require adjustments to the plan’s layout. Be prepared to work with an architect who can tailor these designs to meet your needs.

​Why Shipping Container ADUs Aren’t for Everyone
You may have heard about shipping container homes touted as an affordable and eco-friendly alternative to traditional ADUs. While they might seem appealing, the reality is often less practical. Converting a shipping container into a livable space involves extensive modifications, such as cutting for windows and doors, adding insulation, and reinforcing the structure to meet local building codes. These upgrades can quickly drive costs higher than anticipated.
Although shipping container homes can be a fun project for someone with welding skills and minimal building department oversight, they aren’t a realistic option in urban settings like Aurora, where strict regulations apply.

​​Final Thoughts: Is an ADU Right for You?
Building an ADU can be an excellent way to increase your property’s value while addressing Colorado’s growing housing needs. However, ensuring your project is successful requires careful planning, attention to detail, and expert guidance. That’s where we come in. Our team specializes in designing ADUs that not only meet your specific property requirements but also align with local zoning and building codes. We work closely with you to create a functional and beautiful space that fits your budget and vision.
If you’re ready to start your ADU project, consult with our team at JDC Architecture & Design. We’re here to guide you every step of the way, making the process seamless and stress-free. Contact us today to get started!