If you’re looking for a reliable ADU contractor in San Mateo, W & W Builders Group delivers full-service ADU design and construction tailored to San Mateo zoning, permitting, and building requirements. From initial planning to final inspection, we manage every step so your ADU project is efficient, compliant, and built to last.
Whether you’re planning a rental unit, guest house, or additional living space for family, our experienced team provides a smooth, stress-free ADU construction process from start to finish.
Learn more about our full ADU design and construction services.
A detached ADU is a standalone structure built separately from the main home, often located in the backyard. This option provides the highest level of privacy and flexibility, making it ideal for rental income, guest accommodations, or extended family living. Detached ADUs generally require new foundations, utility connections, and full construction, which can increase the overall project cost and timeline.
An attached ADU is connected directly to the existing residence and is typically created through a home addition. This type of ADU allows homeowners to expand living space while maintaining architectural continuity with the primary home. Attached ADUs can be a great option for families seeking additional space without sacrificing yard area.
A conversion ADU repurposes an existing space—such as a garage, basement, or unused interior area—into a fully functional living unit. Conversion ADUs are often the most cost-effective and fastest option, as they utilize existing structures and utilities. Garage conversions are especially common in San Mateo due to zoning flexibility and reduced construction complexity.
Homeowners planning an ADU often explore additional upgrades such as kitchen remodeling in San Mateo, bathroom remodeling, full home remodeling, or home additions to improve comfort and long-term value.
As an experienced ADU contractor in San Mateo, we follow a structured, proven process designed to keep your project organized, compliant, and on schedule. From the initial consultation to final approval, our team manages every phase to ensure a smooth and stress-free ADU build.
We begin by reviewing your property’s zoning, setbacks, lot size, and existing conditions to confirm ADU eligibility in San Mateo. During this stage, we also discuss your goals, budget, and intended use for the ADU to determine the best approach for your property.
You receive a detailed ADU proposal outlining the full scope of work, estimated construction timeline, and project budget. This step ensures clear expectations, transparent pricing, and a well-defined plan before moving forward.
Our designers and engineers develop custom ADU plans tailored to your property and lifestyle needs while meeting San Mateo building codes and energy requirements. Each design focuses on functionality, efficiency, and long-term value.
We handle the full permitting process, including plan submission, revisions, and coordination with the City of San Mateo. Our experience with local approval requirements helps minimize delays and keeps the project moving forward efficiently.
We guide you through selecting finishes, fixtures, and materials that align with your budget and vision. From flooring and cabinetry to appliances and exterior details, we help streamline decisions so the design process stays organized and on schedule.
Once permits are approved, construction begins. Our dedicated project managers oversee scheduling, trades, inspections, and quality control—ensuring your ADU construction stays on track and meets professional standards.
After construction is complete, we conduct a detailed walkthrough with you and coordinate all final inspections. This step ensures every detail meets expectations and complies with San Mateo requirements.
Your ADU is complete, fully approved, and move-in ready. Whether you plan to rent it, host guests, or use it as additional living space, your new ADU is built for comfort, durability, and long-term value.
Choosing the right ADU contractor in San Mateo makes a meaningful difference in how smoothly your project is approved, built, and completed. San Mateo has specific zoning regulations, permitting requirements, and inspection standards that require local knowledge and experience. Working with a contractor who understands these local processes helps avoid delays, revisions, and unexpected costs.
As a trusted local ADU contractor, we manage the entire ADU process under one roof—keeping your project organized, compliant, and efficient from start to finish.
Local expertise in San Mateo ADU regulations
We understand zoning rules, setbacks, and city approval processes unique to San Mateo.
Design-build ADU services
Designers, engineers, and builders work together to streamline planning, permitting, and construction.
Permit and inspection coordination
We handle plan submissions, revisions, and inspections with the City of San Mateo to reduce delays.
Clear scope of work and transparent pricing
Detailed proposals outline costs, timelines, and expectations before construction begins.
Dedicated project management
A single point of contact ensures clear communication and consistent oversight throughout the project.
High-quality craftsmanship built for long-term value
Every ADU is constructed with durable materials, professional standards, and long-term performance in mind.
Whether you’re planning a garage conversion, attached ADU, or detached ADU, choosing an experienced ADU contractor in San Mateo ensures your project is built correctly, approved efficiently, and designed to add lasting value to your property.
The timeline for building an ADU in San Mateo varies based on the type of ADU, design complexity, and city approval timelines. Most ADU projects follow a general timeline that includes planning and design, permitting, construction, and final inspections.
On average, ADU projects in San Mateo are completed within 4 to 7 months from the initial consultation to final approval. Garage conversions are typically faster, while detached ADUs may take longer due to new construction requirements.
Working with a knowledgeable ADU contractor in San Mateo like W & W Builders Group helps streamline approvals, reduce revisions, and keep your project moving efficiently.
The cost of an ADU project in San Mateo depends on several factors, including the type of ADU, total square footage, design complexity, site conditions, and finish selections. On average, ADU projects in San Mateo typically range from $150,000 to $450,000 or more, depending on scope and construction requirements.
Garage conversion ADUs are usually on the lower end of the cost range because they utilize existing structures and utilities. Attached and detached ADUs tend to cost more due to new foundations, framing, structural work, and utility connections. Permit fees, engineering requirements, and material choices can also impact the final price.
Working with an experienced ADU contractor in San Mateo like W & W Builders Group helps ensure accurate budgeting, a clearly defined scope of work, and transparent pricing before construction begins.
San Mateo homeowners can build several types of Accessory Dwelling Units (ADUs), depending on their lot size, layout, zoning regulations, and intended use. The most common ADU types include detached ADUs, attached ADUs, and conversion ADUs.
A detached ADU is a standalone structure built separately from the main home and is ideal for rental income, guest housing, or private living space. An attached ADU is connected to the existing residence, typically created through a home addition. Conversion ADUs involve repurposing existing spaces—such as garages or interior areas—into fully functional living units and are often the most cost-effective option.
W & W Builders Group helps San Mateo homeowners evaluate which ADU type best fits their property while ensuring compliance with local zoning and building requirements.
In many cases, building a well-designed and properly permitted ADU can increase property value in San Mateo. ADUs add usable living space, create rental income potential, and offer flexibility for extended family, guests, or future resale.
In San Mateo’s competitive housing market, properties with ADUs are often more attractive to buyers due to their versatility and long-term investment potential. The overall value increase depends on factors such as ADU design, quality of construction, layout, and how well the unit integrates with the main home.
Working with a trusted ADU contractor in San Mateo like W & W Builders Group ensures your ADU is built to local codes and designed to maximize both functionality and long-term value.
San Mateo homeowners have several financing options when planning an ADU project. Common options include home equity loans or HELOCs, cash-out refinancing, construction loans, and personal savings. The right choice depends on your financial situation, available equity, and long-term goals for the ADU.
Some homeowners also explore lender-specific renovation programs or incentives, depending on availability and eligibility. Financing terms and approval requirements vary by lender, so it’s recommended to speak directly with a financial professional.
While W & W Builders Group does not provide financing directly, our team helps San Mateo homeowners plan realistic project budgets and scopes so they can confidently explore financing options without unexpected costs later in the process.
The best way to plan for ADU construction in San Mateo is to start with a clear understanding of your property’s zoning regulations, setbacks, budget, and intended use for the ADU. Deciding early whether you want a detached ADU, attached ADU, or conversion ADU helps shape the design, timeline, and overall cost.
Many homeowners coordinate ADU construction alongside full home remodeling in San Mateo to improve layout, flow, and long-term functionality.
Partnering with an experienced local ADU contractor is essential. W & W Builders Group evaluates site conditions, guides homeowners through design and permitting, and creates a realistic construction plan that aligns with San Mateo building codes and approval processes. Early planning, clear scope definition, and professional guidance help prevent delays and ensure a smooth ADU build from start to finish.
