We build homes across California, with active projects in the Bay Area and Los Angeles County. At Apex Homes, we’re passionate about helping people and communities thrive, and we’re always looking to bring our approach to new regions. Wherever families are seeking affordable, high-quality, and thoughtfully designed housing, we welcome the opportunity to partner with you and make your vision a reality.

Pre-designed plans offer a faster, more cost-efficient way to build your home. Rather than starting from scratch, we adapt proven floor plans to fit your property, optimizing placement, parking, storage, and privacy. This ensures your home is perfectly tailored to your site while saving time and money. Apex Homes offers over seven pre-designed plans and is pre-approved in more than 10 cities across California, making it easier than ever to bring your dream home to life.

The timeline to get an ADU depends on city permitting, design choices, and construction complexity, but with Apex Homes’ process it’s streamlined compared to doing it on your own. Here’s what you can expect:

Typical ADU Timeline

1. Feasibility & Design (2–4 weeks)

• Site visit, zoning checks, and feasibility study.

• Drafting floor plans + selecting finishes.

• Pre-approved plans (if available in your city) can cut this stage down to a few weeks.

2. Permitting (1–3 months)

• Submission of plans to the city.

• With Apex Homes’ pre-approved ADU plans, permits can sometimes be issued in as little as 2–3 weeks in certain cities. See our preapproved city lists here.

• Without pre-approvals, expect 6–12 weeks depending on city backlog.

3. Construction (4–6 months)

• Foundation: ~3 weeks.

• Framing & Roofing: ~4 weeks.

• Mechanical/Electrical/Plumbing (MEP): ~4 weeks.

• Interior Finishes: ~6–8 weeks.

4. Final Inspection & Move-In (2-3 weeks)

• Utility hookups, cleanup, and city’s final sign-off

• ADU is now ready for use (rental, family, or personal).

The total timeline for building an ADU depends on your plan and site. If you use a pre-approved plan and have a simple site, you can typically complete the project in 5–6 months from start to finish. For a custom design or a more complex site, the process usually takes 6–10 months.

An ADU cannot stand alone; it must always accompany a main house. California law and most city codes define an ADU as a secondary residential unit on the same lot as an existing or planned single-family or multifamily home. Since the ADU is accessory, it cannot exist as the only structure on a lot.

If your lot is vacant, you have two options. You can build a primary home and ADU together, which some cities allow by submitting plans at the same time. In this case, the city approves the ADU as accessory to the new home. Or, you can build the primary home first and add the ADU later once the main house is permitted or complete.

Building an ADU in your backyard requires careful planning to meet both the unit’s size and your city’s setback requirements. Most cities require at least four feet between the ADU and side or rear property lines. In addition, the total structures on your lot, including your house, ADU, garage, and other buildings, cannot exceed a certain percentage of the lot, which varies by city. Parking requirements also depend on location. Properties near public transit often do not need extra spaces, while other lots may require at least one parking spot.

Apex Homes’ Standard Price Package includes both design services and full construction so that your unit is move-in ready.

Design Package

• Architectural design

• Title 24 energy compliance report

• Structural design & calculations

• Truss system design

• Solar system design

• Building permit application (permit fees themselves not included)

Construction Package (Included)

• Foundation: Site prep + concrete slab-on-grade with standard footing.

• Framing & Roofing: 2×4 stud framing, engineered trusses, plywood sheathing, composite shingle roofing with gutters/downspouts.

• Mechanical, Electrical & Plumbing (MEP): Central HVAC, electric panel, interior plumbing, recessed LED lighting, solar system (battery not included).

• Windows & Doors: Double-pane vinyl windows, solid-core exterior doors, hollow-core interior doors.

• Exterior & Interior Finishes: Stucco/wood siding, drywall, interior & exterior paint, vinyl flooring (light wood color).

• Kitchen: Stainless steel sink, quartz countertops, electric range, hood, dishwasher, Shaker-style cabinets.

• Bathroom: Vanity set with sink, mirror, standard toilet, shower fixture set.

“Custom” means creating an ADU specifically for your needs. We tailor exterior materials, interior finishes, and lighting to suit your lot, lifestyle, and vision. For clients seeking more comprehensive design work, we offer full custom services as an additional option.

In order to get an estimate for your ADU, you can begin your journey with a personal consultation. During this meeting, we will take the time to understand your goals, evaluate your property, and explore what is possible. Based on this information, our team will prepare a customized estimate tailored to your project. Schedule your one-on-one consultation today and take the first step toward bringing your vision to life.

You don’t have to pay the full ADU cost upfront with Apex Homes. Instead, Apex uses a milestone-based payment schedule that spreads costs across different phases of the project.

How Payments Work

• $1,000 – Initial non-refundable retainer

• Initial Deposit (5%) – When you sign the proposal and retainer, covering feasibility studies and site analysis.

• Permit Submission (5%) – Paid once the design package is submitted to the city for permits.

• Construction Start (5%) – When on-site building begins.

• Foundation (15%) – After the foundation is completed.

• Framing (20%) – Once the structural framing is in place.

• MEP (20%) – After Mechanical, Electrical, and Plumbing installations are complete.

• Rough Finish (20%) – Covers drywall, flooring, cabinetry, and interior finishing.

• Completion (10%) – Final payment upon project completion and cleanup (not dependent on utility activation).

This adds up to 100% of the total project cost, but payments are broken into installments tied to progress .

If you have the funds available, you can pay directly out of pocket. Apex Homes uses a milestone-based payment schedule, so you do not need to pay the full project cost upfront. Payments are spread across design, permits, and construction milestones, making the process more manageable than one lump sum.

If you need financing, Apex Homes can help you explore the best options. We partner with multiple trusted loan providers to find a solution that works for your project. Contact us to learn more.

Soft costs usually range from $20,000 – $40,000+, depending on city, size, and site conditions.

Permits & City Fees

• Building Permit – $10,000 – $15,000 depending on jurisdiction.

• Impact Fees (school, parks, etc.) – sometimes waived for ADUs under 750 sq. ft.

Utility Connection Fees

• Water, Sewer, Electric Hookups – $10,000 – $20,000+ depending on existing site conditions and city utility fees.

Curious about your ADU’s potential cost? Book a free one-on-one consultation and let us provide a tailored estimate for your project.

Yes, some areas offer faster permitting through pre-approval processes. Apex Homes already has seven pre-approved ADU plans in 10 cities. With these plans, permits can sometimes be issued in as little as 2–3 weeks.

We’ll work with you to understand your timeline and help you choose the best option for your property and location. Schedule a free one-on-one consultation with us today.

Yes, permits are required, but there’s no need to worry. Our team handles the entire permitting process, guiding you at every step and keeping everything smooth and stress-free. We manage the paperwork, inspections, and approvals so you can focus on the excitement of building your ADU. With Apex Homes, the process is simple, transparent, and designed to make your experience enjoyable from start to finish.

SB9 (Senate Bill 9), also known as the California Housing Opportunity and More Efficiency (HOME) Act, became law on January 1, 2022. It was created to help address California’s housing shortage by making it easier for homeowners to add housing units on single-family lots.

What SB9 Does:

1. Lot Splits (Urban Lot Split Provision)

   • Allows eligible single-family property owners to split their lot into two parcels (as small as 1,200 sq. ft. each).

   • Each lot can then have its own housing units built on it.

2. Two Homes per Lot

   • Each new parcel can have up to two residential units.

   • Combined with a lot split, that means up to 4 homes (2 main house + 2 ADUs) can replace a single-family house.

Wondering if your lot could take advantage of SB9? Let’s talk! Schedule a free one-on-one consultation with our team and explore the possibilities for your property.

In California, an ADU can be up to 1,200 square feet, though some cities have their own local rules that adjust the maximum size. Certain cities adopt more generous regulations to encourage additional housing, while others enforce setbacks, height limits, or lot coverage rules that can reduce the buildable size. Statewide, ADUs under 750 square feet are exempt from impact fees, which is why many homeowners choose to cap their ADU at that size when budgeting is a concern.

Yes, in California you can absolutely rent out your ADU, and many homeowners do. One of the biggest benefits of building an ADU is the opportunity to generate rental income or provide affordable housing for family. State law allows ADUs to be rented long-term, typically on monthly leases or longer. Short-term rentals, such as Airbnb or VRBO, are generally not allowed unless your city specifically permits them. Most cities require leases of 30 days or more to encourage housing stability.

Every ADU we build comes equipped with solar, fully integrated into both the design and construction. This ensures your ADU meets California’s Title 24, Part 6 Energy Code, which requires new residential construction to include solar photovoltaic (PV) systems. Solar not only helps reduce energy costs, but it also increases your home’s sustainability and long-term value. By including solar in every build, we make it simple for homeowners to enjoy clean, renewable energy without extra effort. If you’d like to learn more about how solar works with your ADU and Title 24 compliance, schedule a free one-on-one consultation with us.

Whether you can build an ADU depends on your property type and local rules. For single-family properties, you can usually add one full-size ADU and one Junior ADU (JADU) up to 500 sq. ft., converted from inside your existing home. This means your property could have two extra units alongside your main house (Main House + ADU + JADU), though city rules may vary.

For multifamily properties, you can typically add at least two detached ADUs. State law sets the minimum, but some cities allow more. For example, under SB9 (the lot split law), you may be able to add two main homes and up to two ADUs, depending on lot size and local rules. If you’re ready to explore building an ADU in your backyard, schedule a free one-on-one consultation with us to discuss your options.

Most ADUs go in the backyard because it allows for faster approvals and improves resale value. Building an ADU in the front yard can be more challenging. If you’re considering a front yard ADU, Apex Homes will run a feasibility study. We’ll check your zoning, setbacks, and whether your city allows any exceptions.

Yes. Through our trusted banking partners, we can help you find financing options that fit your project and your goals. Our aim is to make the process simple and clear, so you can move forward with confidence and excitement, knowing your home is within reach.

Detached ADUs in California can be a smart investment for your property and future. A backyard home offers opportunities to generate extra rental income while increasing your property’s value and long-term appreciation. While we’re not financial advisors, our team at Apex Homes can guide you in understanding the potential benefits of adding a detached ADU to your property and how it could support your goals.

Yes, a permanent ADU can give you more space to live, grow, and enjoy your home. It can add bedrooms, bathrooms, and valuable square footage, while also increasing your property’s overall value. To see how an ADU could make a meaningful difference for your home and your future, try our ROI Calculator for a personalized estimate.

Yes, building an ADU will affect your property taxes, but usually in a manageable way. In California, your main home keeps its current assessed value, with only small yearly increases. Only the new ADU gets reassessed. The county uses a ‘blended assessment,’ so your total property tax rises only based on the ADU’s value, not the entire property. This allows you to add a backyard home and increase your property’s value without a major impact on your taxes.