Can You Build an ADU Before the Main House?

ADUs are more affordable housing options, making them marketable to people who possess the financial resources to buy an ADU at the price of $100-150,000 but lack the opportunity to purchase a larger home. Rental opportunities or pressing housing needs may be the primary motivators for exploring alternatives.

The generally accepted definition of accessory dwelling units is that they are secondary and subsidiary structures erected on the same lot as the existing primary residence. Thus, as a rule of thumb, building an accessory dwelling unit prior to the primary dwelling is forbidden. However, in Sacramento, California, there may be certain exceptions in local ordinances and local building codes regarding this matter.

If you intend to embark on ADU construction, you need to learn the ins and outs of ADU construction laws. This article will help you delve into zoning restrictions, local ordinances, and other building regulations to understand better how to implement your ADU construction plans!

Accessory Dwelling Unit (ADU) vs. Main House

The concept of an “accessory dwelling unit” implies that it is an additional structure that merely accompanies an existing structure when the homeowner requires more living space or wishes to gain passive income. This intended use predetermines the sequence of building an ADU and the primary residence. The reasons for this are to comply with safety standards, to ensure sufficient and correct connection to the infrastructure, and to guarantee the availability of all necessary amenities.

The California residential code and local ordinances dictate rules of what is allowable for these units, defining their essence. Accessory dwelling units are smaller, supplementary houses built on the same property your main house occupies. They must have sleeping, cooking, and bathroom facilities, be up to 1200 sq. ft., 16-25 square feet in height (depending on the type), and adhere to 4-foot setback regulations. On the property, there may be only one primary dwelling. Regarding ADUs, property owners can build an ADU and a JADU, if possible, under local regulations.

If the main house purpose is mainly providing individuals and families with living accommodations, accessory dwelling units are quite multipurpose spaces that fulfill a wide array of needs, such as:

• supplemental living space for retiree parents, adult offsprings, or distant relatives;
• temporary lodging for guests;
• rental income and investment with the expectation of increasing the value of the property;
• a hub outside the main residence intended for remote work or entertainment.

All in all, an ADU is a secondary unit that provides you with additional footage within your land and gives you an opportunity to save money if you cannot invest in larger-scale projects.

Building an ADU First in Sacramento

In order to answer the question, “Can you build an ADU before the main house?” you’ll need a thorough understanding of the relevant laws. Due to evolving ADU laws, it is indeed possible under some circumstances to build your future ADU before the primary home. The most common case when it might happen is the following: you build a small unit on vacant land. Right upon the building, your ADU counts as the main residence, but after building a bigger house, you change its status to an ADU.

However, there are several legal and practical considerations property owners should be aware of:

• Certain zoning restrictions

The Sacramento zoning code may allow for the construction of an ADU on a vacant lot. However, you need to make sure your lot falls under the notion of residentially zoned land according to zoning classifications. Also, it’s vital to get yourself acquainted with local land use policies that local authorities established specifically for your area since they may differ greatly depending on your location.

• Local government permission

Apply to your building department if you want your ADU initially considered the primary structure on the property, and then change its status. To demonstrate your intention, you’ll have to submit preliminary plans showing both the ADU and the future main house to the local authorities.

• Temporary primary residence status

Some local governments enable homeowners to build ADUs as temporary primary residences if they comply with all the building and zoning requirements. If you’re planning to build a larger house on the same lot later on, your initial structure will become an ADU.

Changing the status of the construction may involve such steps as updating the property records with the city. The reclassification as an ADU may also entail preparing documentation, scheduling inspections, and paying additional fees. To prevent legal issues, it’s also necessary to check the relevant legal requirements for ADU while noting the difference between them and the regulations for the main house. In addition, you’ll probably need to adapt utility connections for new capacities, review and change legal documentation concerning property, and settle tax-related issues.

To sum up, if you have a small amount of money, you can invest in an ADU, but not in a full-fledged house; you can actually build an ADU first in certain cases. But before commencing the ADU building on an empty lot, it makes sense to consult local planning departments to check if your project is feasible.

ADU Construction Before Main House: Other Alternatives

Aside from the example above, there are also some other situations in which you might be eligible to build an ADU before any other existing structure.

Although it might not be very common, local governments may allow ADUs before the main house in the following cases:

• Multi-unit use lots

Even if it’s a vacant lot, there still may be greater flexibility to construct an ADU before the main house if your lot is in the R-2 or higher density residential zone. This is because in such zones, governments adopt more permissive laws that allow homeowners to maximize land use.

• Countryside and larger plots

Thanks to the densely populated nature of these areas, such lots may be capable of accommodating more units. That is why there may sometimes be more flexibility in the construction sequence. This, combined with typically lower prices, presents a more adaptable approach to property development.

• After the demolition of the main house

If, in the course of renovation or due to damage, you had to demolish the main house, it’s usually possible to receive permission to build an ADU first as your interim shelter.

• City variance

A variance is a special permit that enables the applicant to deviate from the original zoning regulations. Typically, such documents contain certain conditions and terms. You have to observe these rules in order to build the ADU before the primary residence.

Despite the fact that, as a rule, homeowners cannot construct an accessory dwelling unit (ADU) before the main house, some local zoning regulations and ordinances may provide exclusions for peculiar situations and unique conditions.

Various Considerations Before Construction

There are several accessory dwelling unit configurations you can build on your land. ADU projects are divided into detached ADU projects, attached ADU projects, conversion projects, and internal ADU construction projects. However, if you build an ADU before the main house, especially if on an empty lot, your choice is way smaller; since the attached ADU height and positioning, for instance, depend heavily on the main house, it may require very challenging structural engineering. Conversion ADUs and internal ADUs are basically impossible because they imply the transformation of existing space.

Observing Both Main House and ADU Rules

First, the new ADU, although still single construction, must remain compliant with ADU rules. Namely, you cannot build an ADU of more than 1200 sq. ft., or 50% of the size of the intended primary dwelling. Ensure the ADU has sufficient setbacks from each property line. Also, you have to thoroughly project and oversee construction, making sure that your ADU seats are at the proper distance from yet non-existent structures like your future main house.

Future Integration

You’ll need a very detailed plan of each object envisioned for your property to avoid costly alterations and to secure building permits. This stage involves layout and site planning. Not only the ADU and main house but also garages, driveways, and garden spaces should have their place on your blueprints. In addition, ADU must have utility connections for water, sewerage, and electricity. Homeowners should plan where utilities will run along their properties ahead of time. Also, keep in mind that your utilities will need future development when you construct the main residence.

Necessary Permits

It’s essential to realize that the permitting process will have additional steps and hurdles if you opt for building an ADU first. The process may mandate public hearings or extra permit fees to account for the future construction. Selecting this construction sequence, homeowners have to prepare for potential delays and additional requirements as part of the permitting process.

Evolving Lot Development

In case you construct an ADU before the main house, consider designing the ADU with adaptable features such as an open floor plan where you can always rearrange the living room and dining space. Or rooms of multiple uses like a home office/bedroom. Since the main house will not be ready in an instant, you’ll need these versatile spaces to cater to your changing daily needs. By adopting modular or expandable components in the ADU design, you can make it easier to modify or add something to the property, lessening the need for major future rehauls.

All in all, the laws in the field of ADU regulation inevitably vary over time, creating more leeway for less common ADU construction approaches. While it’s still uncommon to build an ADU before the main house, it is not completely impossible for homeowners who are willing to understand the subtleties of building ordinances and local regulations.

Frequently Asked Questions — FAQ

Can you build an ADU before the main house in Sacramento, California?

Building an ADU before the main residence is rare but not completely unimaginable. When the main house is not yet on the site, you can only build an ADU in a few cases specified by local regulations. To learn about specific exemptions for your area, consult with your local planning departments.

How far can an accessory dwelling unit be from the main house?

The distance between an ADU and the primary home may vary based on local zoning ordinances and building codes. The minimal distance between the ADU and the main house in Sacramento, California, equates to a 4-foot setback to guarantee proper spacing and safety measures. However, we recommend keeping an eye on any zoning updates in order to prevent incompliance with the legal requirements.

Are ADUs permissible in Sacramento?

Yes, ADU construction is permissible in Sacramento if your lot is within a residential zone. Yet, your building project should not only observe all the local zoning ordinances and land use regulations but also structural engineering standards, health and safety, energy efficiency standards, etc., to secure permits for ADU building in California successfully. Reach out to local experts to get aid in creating a detailed plan of action!

Can an ADU be larger than the primary residence?

No, accessory dwelling units must be smaller than the primary house. The intention behind it is that the ADU should remain supportive of the main house rather than completely taking its place. Yet, it doesn’t mean that ADUs always need to be very small. The maximum size of the ADU may be as much as 1000–1200 sq. ft. Also, certain regulations, such as compliance with specific egress requirements, may allow an ADU to exceed 1200 sq. ft.

What are the perfect lot characteristics for an accessory dwelling unit?

Your plot should be narrow enough so that the ADU is close enough to the property line. Also, if it has slopes or any other uneven places, it may require costly grading and leveling. Besides, it’s good if your lot has no easements that may prevent you from using certain parts of your land and limit space for construction. It doesn’t mean that you cannot adapt your lot for these constructions, though.