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Book a callConsidering adding an accessory dwelling unit (ADU) to your San Mateo property? With the growing popularity of ADUs, understanding the regulations, especially regarding height limits, is crucial. This guide covers everything homeowners need to know to build a compliant and valuable ADU.
Like many cities in California, San Mateo has seen a surge in the construction of ADUs. These small, self-contained living units offer additional living space, rental income opportunities, and increased property value. Over the past two years, the number of ADU permits issued in San Mateo has skyrocketed by over 80%, demonstrating the appeal of these versatile structures. Whether you want to accommodate family members, generate rental income, or gain extra space, an ADU can be a great addition to your property.
Before you start building, it's essential to understand the specific height regulations for ADUs in San Mateo. The city has set clear guidelines for both attached and detached ADUs to ensure they blend seamlessly with existing neighborhoods.
Detached ADUs can reach a maximum height of 16 feet to the top plateline and 24 feet to the roof peak, measured from the existing grade. If you're planning to build a standalone ADU, these measurements are crucial to ensure compliance with local regulations.
For attached ADUs, the height limits are slightly more generous. These units can go up to 24 feet to the top plateline and 32 feet to the roof peak, measured from the existing grade. This flexibility allows homeowners to integrate the ADU more cohesively into their existing home structure.
In addition to height limits, ADUs in San Mateo must adhere to the daylight plane requirement. This regulation ensures that the ADU does not cast excessive shadows on neighboring properties, maintaining a fair balance between development and community aesthetics. The daylight plane starts at a height of 12 feet and extends into the parcel at a 45-degree angle from the nearest side and rear property lines.
Navigating the permit process can seem daunting, but understanding the steps involved can simplify the experience. When applying for an ADU permit in San Mateo, height regulations are a key consideration.
ADUs are permitted on properties zoned for single-family or multi-family use. However, there are limits on the number of ADUs allowed based on the existing number of units on the property. For example, lots zoned for single-family use may add one ADU or one junior ADU (JADU), while multi-family lots can add ADUs up to 25% of the existing number of units.
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Seeing real-life examples can provide valuable insights and inspiration for your ADU project. Here are a few case studies of successful ADU constructions in San Mateo that adhered to the height regulations and reaped the benefits.
A family built a detached ADU on their property, adhering to the maximum height limit of 16 feet to the top plateline and 24 feet to the roof peak. This ADU now serves as a comfortable living space for their aging parents, providing independence while keeping family close.
Another family opted for an attached ADU, maximizing their space with a height of 24 feet to the top plateline and 32 feet to the roof peak. This unit blends seamlessly with their existing home, offering rental income that supplements their mortgage payments.
On a multi-family lot, a family added an ADU that complied with the 25% unit limit. Their new ADU meets all height and daylight plane requirements, providing additional rental income and increasing the property's overall value.
Adhering to height regulations offers several benefits that extend beyond mere compliance. It ensures your ADU project runs smoothly and enhances the overall value and functionality of your property.
By building an ADU within the allowed height limits, you can maximize the usable living space without compromising on design or comfort. This additional space can be used for various purposes, from housing family members to generating rental income.
A well-constructed ADU that complies with local regulations can significantly boost your property's market value. Prospective buyers often see ADUs as a valuable addition, offering flexibility and potential income streams.
Following height and daylight plane regulations ensures that your ADU harmonizes with the surrounding neighborhood, maintaining a positive relationship with neighbors and preserving the community's aesthetic appeal.
Building an ADU is a significant investment, and expert advice can help you make informed decisions. Here are some tips from industry professionals to help you get the most out of your ADU project.
Focus on functional design elements that make the most of the limited space within height restrictions. Prioritize open floor plans, multi-functional furniture, and ample natural light to create an inviting and spacious atmosphere.
Work closely with local authorities and hire experienced contractors who understand San Mateo's ADU regulations. This collaboration ensures that your project meets all legal requirements, avoiding costly delays or modifications.
Invest in quality materials and finishes that complement your primary residence. A visually appealing ADU can enhance your property's overall curb appeal, making it an attractive option for potential renters or buyers.
Building an ADU in San Mateo offers numerous benefits, from additional living space to increased property value. Understanding and adhering to height regulations is crucial to ensuring a smooth construction process and a successful project. By following the guidelines and expert tips provided in this blog post, you can confidently explore the potential of ADUs on your property.
Ready to take the next step? Schedule a consultation with our ADU experts. today to learn more about how you can build a compliant and valuable ADU in San Mateo and start enjoying the benefits of this versatile addition to your home.
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