Accessory Dwelling Units in Rancho Palos Verdes, CA

There’s something special about creating extra space on your property without leaving the neighborhood you love.

Cornejos Builders: The ADU Experts in Rancho Palos Verdes

We’ve built 24 ADUs in four years, and that experience shows in every consultation, every blueprint review, every pour and frame.

Most contractors talk about timelines and budgets like they’re flexible suggestions. We treat them like promises because we know you’re planning your life around this addition, whether that means aging parents moving closer, rental income to offset your mortgage, or finally getting that home office away from the kitchen chaos.

Our team brings decades of combined construction experience to properties across the Peninsula. We handle the permits (yes, even the tricky coastal commission stuff), we manage the inspections, and we communicate constantly so you’re never wondering what’s happening on your own property.

The difference between a good ADU and a great one often comes down to the details most contractors skip, the waterproofing in our coastal climate, the proper ventilation for year-round comfort, and the layout choices that make 600 square feet feel twice that size.

Building an ADU means adding real value to your home and your life. The families we work with aren’t just thinking about today. They’re thinking about rental income that covers their property taxes, about keeping family close as parents age, about having a dedicated workspace that doesn’t disappear when dinner gets made. We build with that long view in mind, using materials and methods that last.

Alexsander Cornejo – Owner of Cornejo Builders

Hi, I’m Alexsander Cornejo, the owner and founder of Cornejo’s Builders. I started working in the remodeling and construction industry right out of high school, in 2009.

With Cornejo’s Builders, the goal is to give back to the city I grew up in. I want to send a message of hope and inspiration: any dream can be achieved, no matter where you come from, if you put in enough work and dedication.

Our Completed Projects Across Rancho Palos Verdes

Take a look through our portfolio, and you’ll see the range of ADU projects we’ve completed around the Peninsula. Each one solved a different challenge, from steep hillside lots to maximizing space in compact backyards. These photos tell the story better than we can.

60+ projects done

100+ of families helped

1:1 approach to your project

Unsure about choosing us? Request a quote to get to know us better! Let’s discuss your project. Or, call us at (562) 319-3178 now!

Why Rancho Palos Verdes, CA, Residents Choose Us

Our reviews speak for themselves, and we’re proud of every one. Read through them and get a sense of how we work, how we communicate, and what it’s like to have us on your property.

Lety Ortega

Rated 5 out of 5

Called Cornejo’s Builders after seeing their beautiful work on TikTok. Spoke to the owner regarding an ADU project.

Alex always returned my calls, explained throughly how the project would be completed. Love how his company is an all in one stop. They definitely handle everything from getting permits, architect, plumbing, electrical etc. Turn key ready, his prices are very reasonable and is willing to work around your budget. Alex was very understanding when I explained why I had to put a hold on the the project. He definitely treats his customers like family.

Yahritza Orellana

Rated 5 out of 5

Had a truly great experience with Alex. Cornejo’s Builders just completed converting my crawlspace/basement into an ADU (studio with new bathroom and kitchen).

What made the experience even more valuable was that the owner himself (Alex) came over for a consultation. Other companies just send their sales reps and most of the time they don’t even know anything. Feeling important is always a positive I can’t wait to work with them again. I highly recommend them. You can tell Alex is passionate about what he does, his clients, and his company.

ADU Costs in Rancho Palos Verdes, CA

ADUs in our area typically run between $80,000 and $250,000, depending on what you’re building and how you’re building it.

A basic garage conversion sits at the lower end, while a ground-up two-bedroom unit with a full kitchen and bath falls toward the higher end. These numbers come from our actual project estimates over the past few years, but your specific cost depends on your specific plans.

What drives the price up or down:

Square footage matters. A 400-square-foot studio costs significantly less than an 800-square-foot one-bedroom. But layout complexity plays a role, too. Simple rectangular floor plans cost less to frame and finish than units with multiple rooms, separate entrances, or custom features.

Rancho Palos Verdes has challenging terrain. Hillside lots often require retaining walls, special foundation systems, or extensive grading. If your property slopes significantly, budget for the additional structural work needed to make everything safe and level.

Standard finishes keep you in the mid-range. Upgraded appliances, custom tile work, high-end countertops, and specialty lighting add up quickly. We work with your budget to find the sweet spot between quality and cost.

Running new electrical, plumbing, and HVAC to a detached ADU costs more than converting an existing garage space with existing utilities. Your existing home’s utility capacity determines how much work is required. Older homes often need panel upgrades even for modest ADU additions.

Coastal properties sometimes trigger additional review processes. Architectural plans, engineering reports, permit fees, utility connection charges, these soft costs typically run $15,000 to $25,000, depending on project complexity. We handle all the paperwork, but the costs still factor into your total budget.

Get specifics by sharing your plans with us. We’ll visit your property, talk through your goals, and give you a realistic number based on what you actually want to build.

Budget and Timeline You Can Count On

We know the two questions keeping you up at night: what will this actually cost, and how long will our backyard be a construction zone? Those concerns are completely reasonable. We take them seriously because we’ve been doing this long enough to understand that construction work disrupts your daily life and affects your finances.

If you’re building a $150,000 unit that generates $2,500 monthly in rental income, that’s $30,000 per year. In five years, you’ve recouped your investment. In fifteen years, that ADU has generated $450,000 in income while also increasing your property value. Or maybe you’re not renting it. Maybe you want to keep aging parents close and avoid $5,000 in monthly assisted living costs. The numbers work when you view them through the lens of long-term value, not just upfront expense.

Most ADU projects take four to seven months from permit submission to final inspection. We stick to our schedules because we plan realistically from the start, accounting for material delivery times, inspection wait periods, and weather delays. You won’t find our crew disappearing for weeks to juggle other jobs. We respect your property, keep the site clean, and communicate constantly about what’s happening next.

How We Build Your ADU

We handle everything from initial design to the final walkthrough. You can focus on planning how you’ll use the space.

Collaborate

We listen first, then design around your needs and property.

Build

Our crew arrives on time and keeps you informed on the daily progress.

Enjoy

Move in knowing the work was done right the first time.

Common Questions About ADUs in Rancho Palos Verdes

How long does the permit process take in Rancho Palos Verdes?

Permit timelines vary, but expect two to four months from submission to approval for most ADU projects. The coastal zone adds another layer of review that can extend timelines, especially if your property sits near the bluff or in environmentally sensitive areas. We’ve navigated these requirements dozens of times and know exactly what documentation the planning department needs to move applications forward quickly. Starting your architectural plans while we prepare the permit package saves time overall.

Can I use my ADU as a rental property?

Absolutely, and many of our clients do exactly that. Rancho Palos Verdes allows ADU rentals with some basic requirements. You’ll need to live on the property yourself, meaning you can rent either the main house or the ADU, but not both. Short-term vacation rentals under 30 days aren’t permitted, but long-term tenants work perfectly. The rental income often covers a significant portion of your mortgage payment or property taxes, making the ADU investment pay for itself within a few years.

Do ADUs require separate utility meters?

Not always, but separate meters give you options. If you’re renting the unit, separate metering means tenants pay their own utilities instead of you covering those costs. For family members or personal use, sharing utilities keeps things simpler. We can run everything off your main house systems or set up completely independent utilities, depending on your preference.

What's the minimum lot size needed for an ADU in Rancho Palos Verdes?

There’s no absolute minimum lot size, but practical space requirements usually mean properties under 5,000 square feet get challenging. You need room for the ADU itself, required setbacks from property lines, parking spaces, and code-required outdoor access. Hillside lots sometimes work better than you’d expect because we can build on different elevations. Schedule a site visit, and we’ll tell you honestly whether your property can accommodate what you’re envisioning. Sometimes, creative design makes seemingly impossible lots work beautifully.

Ready to Add a Fresh Space to Your Property?

Alexsander Cornejos

Call us at (562) 319-3178 or visit our contact page here, and let’s talk about what an ADU can do for your family.

Maybe you need rental income, or you’re tired of turning away guests because you don’t have room. Whatever the reason, we’ve built enough Accessory Dwelling Units to know that the families who pull the trigger on this project never regret it. The only regret we hear is not starting sooner.

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Rancho Palos Verdes sits on the southern tip of the Palos Verdes Peninsula, known for dramatic coastal bluffs, hiking trails, and some of the best ocean views in Los Angeles County. The Trump National Golf Club overlooks the Pacific, while the Wayfarers Chapel offers stunning glass architecture nestled into the hillside. Residents value the slower pace and natural beauty, and building an ADU here means keeping family close to these amenities. The City of Rancho Palos Verdes maintains strict building standards that protect the area’s character while allowing thoughtful property improvements.