Fast-Track Your Backyard Build: Should You Use California’s Pre-Approved ADU Plans?

Thinking about building an ADU but overwhelmed by permits, design costs, and decision fatigue?
You’re not alone — and here’s the good news:

Many cities across California now offer free or low-cost pre-approved ADU plans that can save you time, money, and a few headaches.

But are they right for you?

Let’s break down what these plans are, when they make sense, and how to use them to your advantage.

🤔 What Are Pre-Approved ADU Plans?

Think of them like ready-to-go blueprints for your backyard home. These are architectural designs that your city’s building department has already reviewed and approved.

That means:

• ✅ They meet state and local building codes
• ✅ They don’t need extra design review
• ✅ You can use them to speed up permitting
• ✅ Some are even free to download

Cities like Los Angeles, San Jose, San Diego, and Santa Cruz have already jumped in with public libraries of stylish, efficient designs.

✅ Why You Might Want One

Here’s when a pre-approved ADU plan can be a total game changer:

1. You want to save months of time

Some projects wait 3–6 months for permit approval. Using a pre-approved plan? You could cut that in half — or more.

2. You’re on a budget

Custom architectural plans often cost $5K–$20K. Pre-approved plans? Sometimes $0. Seriously.

3. Your lot is pretty standard

If your lot is flat, rectangular, and meets basic zoning, a standard plan is often a plug-and-play option.

4. You just need a solid rental, guest house, or in-law suite

If you’re not trying to design the next Dwell cover, a pre-approved plan is plenty.

🚫 When It’s Not the Right Fit

These plans aren’t for everyone. You might want to explore custom options if:

• Your lot is narrow, sloped, or oddly shaped
• You’re converting an existing garage or basement
• You want to match the exact look of your primary home
• You need unusual accessibility features

Also, some cities only allow minimal changes to pre-approved plans. If you want to move walls or add skylights, it may trigger a full plan review anyway.

💡 Pro Tip: Start Simple, Then Customize

Many homeowners begin with a pre-approved plan and then work with a designer to tweak it slightly — for example, flipping the layout or changing window placements. Some cities still honor the original approval with minor edits, saving you review time.

We recommend this if you want the best of both worlds: speed + personalization.

🔍 Where to Find Pre-Approved Plans

Here are just a few California cities offering ready-to-go ADU designs:

• Los Angeles
• San Jose
• San Diego
• Santa Cruz County
• Oakland

🧰 Final Thoughts: Is It Worth It?

If you're looking to build quickly, spend less, and skip red tape, pre-approved ADU plans are absolutely worth considering. Just make sure to:

• ✅ Check your lot conditions
• ✅ Review what your city allows
• ✅ Match the plan to your goals (rental income, family housing, resale boost, etc.)

Need help evaluating your options? We’ve got your back.

🚀 Ready to Start Your ADU Journey?

DM us “PLAN” on Instagram @myaduhub, or visit myaduhub.com to get matched with a builder or pre-approved design that fits your lot and lifestyle.

‍