Mediterranean Cottage Style ADU for Young Family
Via Cancion, San Marcos, CA 92078
Homeowner Story: House younger family
Other Features: Garage, Covered porch
Special Circumstance: Septic
Homeowner InterviewA Cottage Style ADU in San Marcos Vineyard
“We didn’t want anything that looked like a prefab. We wanted something that fit with the aesthetic of the vineyard – a more rustic Italian look – and SnapADU really brought that vision to life.” – Marina & Will Evans, Homeowners in San Marcos
This beautiful property in San Marcos is located on a working vineyard. The homeowner wanted to share her estate with her newly married daughter and son-in-law, to give them the opportunity to save up to purchase their own home in the future. This custom cottage style 1200 sqft, 2 bedroom, 2 bathroom ADU with an attached garage has a large open concept kitchen and great room, with an island, fireplace, and French doors leading out to a large deck overlooking the property.
Overcoming Design Challenges
The design phase of this project was particularly challenging since the new cottage style ADU is situated on a hillside. Additionally, ADU regulations in San Marcos were changing during the design phase, requiring close coordination with the city to ensure compliance. The property also has a septic system, which was expanded to accommodate the two new bathrooms in the ADU.
“They worked closely with us to ensure we got exactly what we wanted, from the chimney design inspired by Italy to the large master bathroom. I would definitely recommend SnapADU. They were communicative, transparent, and overcame any challenges that came up during the process.” – Marina & Will Evans, Homeowners in San Marcos
A Thoughtfully Designed Floor Plan
This cottage style ADU layout maximizes space while providing modern conveniences. Both bedrooms are positioned on the same side of the unit, ensuring a cohesive and private living space. The primary suite features a walk-in closet and an en suite bathroom with dual vanities. The second bedroom also includes an en suite bathroom, which has an additional door for shared access from the great room.
How We Built a 1200 Sqft ADU in San Marcos
You might be wondering how we built a 1200 sqft ADU in San Marcos when the current maximum size is 1000 sqft. This unit was permitted back in 2020 before San Marcos established its own ADU size restrictions, meaning the State law, which allows up to 1200 sqft, was still in effect at the time.
By blending a rustic aesthetic with thoughtful design, this cottage style ADU seamlessly integrates into the vineyard landscape while providing a comfortable and functional home for extended family.
Read more about multigenerational homes.
Floor Plan:
2BR/2BA 48×31 L-Shape
Community:
The San Marcos ADU Guide
SnapADU is proud to have been selected by the City of San Marcos through a competitive bid process to design the City’s pre-approved ADU plans. This experience has given our team a deep understanding of San Marcos ADU regulations, permitting requirements, and development standards.
One of the most unique aspects of building an ADU in San Marcos is the Community Facilities District (CFD) process, commonly known as Mello-Roos. Depending on the property location, homeowners may need to annex into an existing CFD or pay an in-lieu fee as part of the development process. This requirement can add several months to a project’s timeline and is often one of the biggest surprises homeowners encounter.
San Marcos also has several development standards that differ from neighboring jurisdictions. Detached ADUs are generally limited to 1,000 square feet, and the city requires a 10′ building separation between between the primary residence and detached ADU. Additionally, ADUs are expected to be architecturally compatible with the primary residence, making exterior design coordination an important part of the planning process.
San Marcos ADU Permitting
Most ADU permits in San Marcos are approved within approximately 5 to 7 months after submission, although timelines vary depending on project complexity and whether CFD processing is required.
Permit costs are moderate, generally range from approximately $10-14/sqft, depending on project size and scope. The City accepts digital permit submissions, which helps streamline portions of the review process.
One unique requirement in San Marcos is the building verification survey and setback certification process for detached ADUs. These surveys confirm that the ADU is being constructed in the approved location and complies with setback requirements before inspections can proceed.
As of May 2025, San Marcos no longer requires soils reports for most ADU projects. A soils investigation is generally only required when grading is proposed or if site conditions identified during construction warrant additional geotechnical review.
San Marcos Pre-Approved ADU Plans
San Marcos offers a library of pre-approved ADU plans designed to help homeowners reduce upfront design costs and simplify the permitting process.
SnapADU was selected by the City through a competitive process to design these plans, which were created to balance efficient permitting, construction affordability, and high-quality design. The plans provide homeowners with a proven starting point while still requiring site-specific review to address grading, utilities, setbacks, and other property conditions.
While pre-approved plans can reduce design time and create greater predictability, homeowners should understand that every property is unique. Many homeowners ultimately choose between pre-approved, standard, semi-custom, and fully custom plans depending on their goals, budget, and desired level of customization. Learn more about pre-approved ADU plans.
