California is short on housing, and land is expensive. That combination has pushed a lot of homeowners to look at what they already have: their own backyard.
An Accessory Dwelling Unit, or ADU, lets you add a second, fully livable home on your property without buying more land. Over the past several years, ADUs have gone from a niche idea to one of the most common home projects in the state.
If you’re thinking about building one, it helps to understand what an ADU actually is, how the process works, and what to expect from start to finish. Here’s a straightforward look at ADU construction, based on how one San Jose general contractor, NuHome Remodeling, approaches these projects.
What Is an ADU?
An ADU is a small, separate home built on the same lot as your main house. You may also hear it called an in-law unit. It’s not a spare room or a converted closet. A true ADU has everything a normal home needs.
- A private living area
- A full kitchen
- A bathroom
- Its own entrance, separate from the main house
An ADU can be attached to your existing home, sharing a wall, or it can stand completely on its own in your backyard. Which option works best usually comes down to your lot size, local restrictions, and what you want the space to do.
Why Homeowners Are Building ADUs
People build ADUs for a few main reasons, and most of them come down to needing more from the property they already own.
- Rental income: A separate unit can be rented out, giving you a steady source of extra income.
- Family housing: Many homeowners build an ADU for aging parents or adult children, giving everyone their own space while staying close.
- More privacy: A detached unit keeps guests or family members from feeling like they’re living on top of you.
- Room to grow: As families grow, an ADU offers more living space without the cost and stress of buying a new house.
The ADU Construction Process
Good ADU construction follows a clear path from idea to move-in day. NuHome Remodeling breaks the process into six steps.
1. Your Vision
It starts with a conversation. You share your goals for the space with a project manager, whether that’s a rental unit, a place for family, or simply more room.
2. Design and Planning
A designer works with you to draft a plan that fits your property and matches what you want. This stage also covers the permitting process, which is required for any ADU project in California.
3. Shopping for Finishes
Once the plan is set, you’ll pick out materials and finishes with help from your designer. This is where the unit starts to feel like an actual home, with your choices in flooring, fixtures, and cabinetry.
4. Construction
With the planning and shopping done, the building crew takes over. This is the longest phase, where the ADU actually gets built, from the foundation up.
5. Quality Check
Before anything is considered finished, the project manager and on-site foreman inspect the work. This step makes sure everything meets the standard promised at the start.
6. Celebrate
The last step is simple: move in and enjoy the new space.
A Real ADU Project: San Mateo, CA
It helps to see what this looks like in practice. NuHome Remodeling completed a detached ADU casita in San Mateo, finished in January 2025. It’s a good example of what a fully custom ADU can include.
- 1,250 square feet, built as a detached structure
- Spanish Mediterranean architecture with modern touches
- Smooth finish walls, arched doors, and arched windows
- Natural stone flooring throughout
- A custom chef’s kitchen
- A spa-style bathroom with a steam sauna
- High ceilings and rounded architectural details
This project shows that an ADU doesn’t have to feel like a basic add-on. With the right design and construction team, it can be built with the same care and detail as a full custom home.
Choosing a Contractor for Your ADU
An ADU touches almost every part of home construction: design, permitting, framing, plumbing, electrical, and finishing. Picking a contractor who handles the whole process, rather than juggling separate companies for each step, tends to make the project smoother.
NuHome Remodeling is a general contractor based in San Jose, California, and has been helping homeowners with remodeling and construction projects for over 15 years.
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A few things worth knowing about the company:
- It’s a family-run business, licensed under Lic. #1069117.
- Clients work with a dedicated project manager, a hand-selected crew, and an on-site foreman for every project.
- The team handles ADUs from blueprints through final construction.
- ADUs can be built attached to the home or as a stand-alone structure, depending on the property.
- The company is rated five stars on Thumbtack, top rated on HomeAdvisor, and rated five stars on Houzz.
- NuHome serves San Jose and nearby areas, including Campbell, Cupertino, Los Gatos, and Saratoga.
- Summary
An ADU is a full second home on your property, complete with its own kitchen, bathroom, living space, and entrance. Homeowners across California are building them for rental income, family housing, and extra privacy.
A solid ADU project moves through clear stages, starting with your vision and ending with a finished, move-in ready space. Projects like the San Mateo casita show what’s possible when design and construction come together with real attention to detail.
If you’re considering an ADU for your California home, NuHome Remodeling can walk you through the process from the first conversation to the final walkthrough.
Get in touch:
Call: (408) 819-6296
Email: info@nuhomeremodeling.com
WhatsApp: message NuHome directly at (408) 819-6296
Visit: 1580 Oakland Rd C202, San Jose, CA 95131
Hours: Monday-Friday, 9:00 AM-5:00 PM
Schedule a free in-home consultation and find out what an ADU could look like on your property.
