Building an ADU in California? Save Time and Money with Pre-Approved Plans

Find out whether pre-approved ADU plans are the right choice for you

May 4, 2023

Looking to build an ADU in California without the hassle and expense of custom designs? Look no further than pre-approved plans!

ADUs are definitely a popular choice for California homeowners these days, but let's face it - the design and permitting process can sometimes be a real headache. Luckily, there's a solution: pre-approved ADU plans.

With a pre-approved plan you get to skip most of the design phase and expedite the permitting process as the design is already reviewed by local building departments. This can save you up to $10,000 in fees and weeks or even months of time spent on getting your permits.

To make an informed decision about pre-approved ADU plans, it's crucial to weigh their advantages and disadvantages. So, continue reading to explore both sides and determine if it's the right choice for you.

What are Pre-Approved ADU Plans?

Pre-approved ADU plans are architectural designs for ADUs that have been reviewed and approved by city building and/or planning departments, allowing for an accelerated permitting process and minimizing the risk of small planning errors causing delays. To put it into perspective, imagine spending tens of thousands of dollars on a custom design, only to find out that it won't be approved for a permit. Well, pre-approved plans aim to help you avoid these exact scenarios and enjoy a more streamlined process instead.

Are Pre-Approved Plans Submitted As They Are?

No. Pre-approved plans are around 70-80% complete but you will still be required to make property-specific modifications and submit the required documentation.

This usually includes a site/plot plan and any additional site-specific calculations. It's advisable to check with your local building department to confirm their specific requirements.

Pros and Cons of Choosing Pre-Approved ADU Plans

There are both potential benefits and drawbacks to pre-approved ADU plans. And depending on your specific situation, one will likely outweigh the other.

Some of the biggest advantages of pre-approved ADU plans include:

  • Saving time: With pre-approved ADU plans you avoid the design process and reduce the permission obtaining time, saving weeks' or even months’ worth of time.

    For example, by taking advantage of the pre-approved ADU program, units in San Jose can be built in around 90 days.

  • Saving money: Pre-approved plans are less expensive and usually have lower permitting fees. Some cities even offer certain plans for free.
  • Low upfront cost: Hiring an architect typically costs 8-15% of the project and needs to be paid upfront. This can be a significant amount (up to $30k) for homeowners who may not have substantial savings dedicated to design;
  • Compliance with local building codes: Pre-approved ADU plans are reviewed by local building and planning departments, avoiding potential wasted expenses on a design that may not be approved.

On the other hand, some of the biggest disadvantages are:

  • Limited customization: Pre-approved ADU plans may not offer as many design options as custom plans, limiting your ability to personalize the space;
  • May not fit unique properties: The pre-approved plans may not fit the unique characteristics of a particular property, such as the size, slope, or shape of the lot;
  • May not be cost-effective in the end: If the permitting process is slow or inefficient, or if the jurisdiction does not prioritize ADUs or is understaffed the time-saving benefit of pre-approved plans may not be significant.

Types of Pre-Approved ADU Plans

California’s pre-approved ADU plans fall into two categories:

  • City-owned plans
  • Designer-owned plans

City-Owned Plans

City-owned plans are created by city-selected architects and are usually less expensive than designer-owned plans or even free. While city-owned plans offer fewer design options, they are more likely to comply with local building codes and regulations.

However, there are several drawbacks to city-owned plans. For starters, you’ll still need to find a designer to:

  • Draw up your site plans;
  • Do your Title 24 calculation (A report that confirms your building design adheres to the energy efficiency standards set by California Title 24);
  • Work on additional requirements specific to your property.

Plus the responsibility to find a builder falls onto you as well.

Designer-Owned Plans

Designer-owned plans are created by private architects or design firms and submitted for pre-approval by the city.

The advantage of working with designer-owned plans is that it allows you to work on small modifications to the design, while the plan still maintains a pre-approval status. This is because the original designers are usually the only ones who can make these changes due to liability issues. However, they sometimes may be available for purchase as a license, allowing you to hire your own architect to modify the plans as needed.

In addition, the designer can handle your permitting and construction process, resulting in an overall smoother experience.

And lastly, designer-owned plans offer more variety in design options, although they tend to be more expensive than city-owned ones, which can be found for free.

Where to find pre-approved ADU plans?

Most cities that offer pre-approved ADU plans have them listed on their website. Depending on whether the plans are city-owned or designer-owned, they either have them available to download for free or a certain fee or offer images and contact information of the designers.

Some of the cities in California that offer pre-approved ADU plans include:

How to Choose the Right Pre-Approved ADU Plan for Your Property?

When it comes to selecting the right pre-approved ADU plan for your property, there are several essential tips to keep in mind:

  • Analyze your property: Review your property's size, shape, slope and orientation and ensure that the pre-approved ADU plan you choose is a good fit.
  • Check local regulations: Understand local zoning and building regulations that may affect your choice of pre-approved ADU plans and ensure that the plan complies with them.
  • Consider your lifestyle: Think about how you plan to use the ADU and select a plan that meets your needs, such as a separate office, rental unit, or guest house.
  • Seek professional advice: Consult with an ADU specialist, architect, or builder to help you choose the best pre-approved ADU plan for your property and budget.
  • Understand the cost-benefit analysis: Compare the costs of building a custom ADU vs. a pre-approved ADU and consider the savings in time and money that a pre-approved ADU plan can provide.

Custom versus Pre-Approved ADU Plans: Which Option Suits Your Needs?

Deciding between custom and pre-approved ADU plans ultimately comes down to your needs and priorities. While pre-approved ADU plans offer many benefits such as reduced costs and time-saving benefits, they also come with limitations in design options, fitting unique properties and meeting personal preferences. However, they can be more expensive and time-consuming to develop and permit.

To sum it up, pre-approved ADU plans are ideal for homeowners who prioritize cost and efficiency, while custom plans are more suitable for those seeking a unique and tailored ADU design.

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