If you’ve started researching ADU plans online, you’ve probably seen a wide range of options—from ultra-generic stock plans to fully custom architectural services.
But not all plans are created equal—and the differences can have a big impact on your budget, timeline, and peace of mind.
Let’s break down the difference between stock plans and pre-designed plans, and help you understand which one might be the right fit for your project.
What Are Stock Plans?
Stock plans are mass-produced home designs available from national websites or drafting services. These plans are often designed for generic zoning codes and may not meet the specific requirements of your city, lot, or state.
Pros:
- Lower upfront cost
- Wide variety of designs
- Fast to download
Cons:
- Often not code-compliant without major revisions
- May require additional drawings or engineering to meet local permitting standards
- Not tailored to your lot size, solar orientation, or utility access
- May need an architect to redraw all drawings.
What Are Pre-Designed Plans?
Pre-designed plans are architect-developed layouts created with a specific region or building type in mind—like ADUs in Arizona. They’re not custom-designed for your property, but they’re built to be much closer to permit-ready with fewer surprises and fewer required edits.
Pros:
- Designed with Arizona zoning and climate in mind
- Created by a licensed architect (not a generic plan bank)
- Easier path to permitting
- Can often be modified at a lower cost than starting from scratch
Cons:
- Not fully customized to your site or preferences
- May still require some site-specific adjustments or utility coordination
Why the Difference Matters
When it comes to ADUs, zoning and code compliance are everything. A beautiful plan that doesn’t meet your jurisdiction’s setback, height, or coverage requirements can become a costly delay—or even a dead-end.
At PlanHAUS, our pre-designed plans are created with Arizona homeowners in mind, designed by a licensed architect familiar with local code and permitting workflows. That means fewer headaches, fewer redraws, and more confidence as you move forward.
Not Sure Which Path is Right for You?
If you’re comparing stock plans, pre-designed options, or full custom services—we can help you weigh the pros and cons. We’ll take a look at your lot, your goals, and your city’s requirements to help you find the best-fit solution.
