As the demand for housing increases in California, many homeowners are looking for ways to maximize their property’s potential. One popular solution is building an Accessory Dwelling Unit (ADU), a secondary housing unit on a residential lot that can provide additional living space, rental income, or even a private retreat for family members. Millbrae, a city in San Mateo County, is no exception to this trend, as its proximity to major job centers like San Francisco and Silicon Valley makes it an attractive location for ADU construction.
However, building an ADU in Millbrae is not as simple as just adding a small house to your backyard. There are various legal, financial, and logistical factors to consider before you begin construction. In this article, we will explore the five key things to consider when building a Millbrae ADU to help ensure the process goes smoothly and meets your needs.
1. Understanding Millbrae's Zoning and Building Regulations
Before starting any construction project, it is crucial to understand the zoning laws and building codes that apply to your property. Millbrae, like many cities in California, has specific regulations governing the construction of ADUs. These regulations are designed to ensure that the development of new units is safe, aesthetically compatible with the neighborhood, and meets environmental standards.
Zoning Requirements for ADUs in Millbrae
The City of Millbrae follows the California State ADU laws, which have undergone significant changes in recent years to make it easier for homeowners to build these units. However, local jurisdictions can still impose additional rules. Some of the key zoning considerations include:
Minimum Lot Size: Millbrae does not have a specific minimum lot size for ADUs, but your lot must be large enough to meet parking, setback, and other zoning requirements.
Setbacks: There are setback requirements, which dictate how far the ADU must be from property lines. Typically, a rear setback of 4 feet and side setbacks of 3 feet are common, but you should confirm with the city.
Height Limits: The maximum height for a detached ADU in Millbrae is generally 16 feet, but this can vary depending on the design and location of the unit.
Parking: ADUs often require one off-street parking space unless the unit is within half a mile of public transportation, in which case the parking requirement may be waived.
ADU Design Considerations
Millbrae’s design standards are intended to ensure that new structures are compatible with the existing neighborhood. This includes requirements for architectural design, building materials, and landscaping. When designing your ADU, you should consider factors such as:
The unit's overall aesthetic, which should complement the main house and surrounding properties.
Privacy concerns, such as minimizing the number of windows that face neighboring properties.
How the unit will fit within the available space on your lot, ensuring that you still have access to outdoor areas like your garden or patio.
It’s crucial to work with a local architect or designer who is familiar with Millbrae’s specific ADU regulations to avoid potential delays or costly redesigns later on.
2. Permits and Approvals: Navigating the Process
Obtaining the necessary permits and approvals is one of the most important and sometimes time-consuming aspects of building an ADU. In Millbrae, the approval process typically involves submitting plans to the city’s Planning Division, obtaining building permits, and complying with local environmental review standards.
Steps in the Permit Process
Pre-Application Consultation: Before you begin preparing your plans, it may be beneficial to schedule a pre-application consultation with the Millbrae Planning Division. This allows you to discuss your project with city staff and get feedback on potential issues related to zoning, design, and permitting.
Submit Plans: Once you have a design for your ADU, you’ll need to submit detailed plans to the city. These plans should include site plans, floor plans, elevations, and a description of the materials to be used. It’s important to include all required information to avoid delays.
Planning Review: After submission, your plans will be reviewed by the city’s planning staff to ensure compliance with zoning codes, building regulations, and other requirements. If your plans meet all the necessary criteria, they will be approved, and you can move forward with building permits.
Building Permits: After the planning review, you will need to apply for a building permit. This permit authorizes you to begin construction, and it ensures that your ADU will be built according to safety standards and the approved design.
Inspections: Throughout the construction process, you will need to schedule inspections at various stages to ensure compliance with building codes and safety standards. These inspections will typically cover the foundation, framing, electrical work, plumbing, and final occupancy.
Potential Delays in the Permit Process
While California has made efforts to streamline the permitting process for ADUs, some local factors can still lead to delays. For example, if your property is located in a historic district or near an environmentally sensitive area, additional reviews may be required. It’s essential to allow ample time for permits and to plan for any potential delays that might arise during the review process.
3. Budgeting for Your Millbrae ADU: Costs and Financing Options
Building an ADU can be a significant financial investment, and it’s essential to carefully plan your budget. Costs can vary widely depending on the size and complexity of the project, as well as the materials and finishes you choose.
Average Cost of Building a Millbrae ADU
The cost of building an ADU in Millbrae typically ranges from $200,000 to $500,000 or more, depending on factors like square footage, site preparation, and design complexity. Here’s a breakdown of some of the main cost factors:
Construction Costs: Labor and materials make up the bulk of the cost of building an ADU. Depending on the quality of materials you select, construction costs can vary widely.
Site Preparation: If your lot requires significant grading, demolition, or utility upgrades, this can add to the cost. For example, if your ADU requires new water, sewer, or electrical connections, these costs can add thousands of dollars to your budget.
Design and Permitting Fees: Hiring an architect or designer to create your ADU plans, as well as paying for permits and inspections, will also contribute to your overall expenses.
Interior Finishes: The quality of the interior finishes (e.g., flooring, cabinetry, fixtures) can impact your budget significantly. Choose wisely depending on whether your goal is to rent out the ADU or use it for personal purposes.
Financing Your ADU
Financing an ADU can be challenging, but there are several options available:
Home Equity Loan or HELOC: If you have significant equity in your home, you may be able to use a home equity loan or line of credit (HELOC) to finance the construction of your ADU.
ADU Financing Programs: Some banks and lenders offer specific loan programs for ADUs. These loans may have more favorable terms than traditional home improvement loans and could help cover both construction and permitting costs.
Personal Savings: If you have savings set aside for a home improvement project, using your personal funds to finance your ADU could be a cost-effective option.
Rental Income: If you plan to rent out your ADU, the rental income can help offset some of the costs over time. However, it’s essential to research the local rental market to ensure you can generate enough income to justify the investment.
4. Managing the Construction Timeline
Building an ADU is a complex process that can take several months, depending on the size and complexity of the project. Managing your construction timeline is critical to ensure that the project stays on schedule and within budget.
Steps to Manage Your Construction Timeline
Work with an Experienced Contractor: One of the best ways to manage your timeline is to work with a reputable and experienced contractor who has experience with ADU construction. A good contractor will be able to handle logistics, secure permits, and avoid common pitfalls.
Create a Realistic Timeline: Before construction begins, work with your contractor to develop a timeline that accounts for the various stages of the project, including permits, inspections, and material delivery. Be sure to build in some buffer time for unforeseen delays, such as bad weather or supply chain issues.
Regular Check-ins: Stay involved throughout the construction process by scheduling regular check-ins with your contractor. This will help ensure the project is progressing on schedule and allow you to address any issues that may arise.
Plan for Contingencies: It’s important to plan for unexpected delays or costs that may arise during the construction process. Having a contingency fund of 10% to 20% of the total budget can help cover unforeseen expenses without derailing your project.
5. Environmental and Sustainability Considerations
California has some of the most stringent environmental regulations in the country, and it’s important to incorporate sustainability into your ADU design. Building an eco-friendly ADU can reduce your carbon footprint, save on utility bills, and make your property more attractive to environmentally conscious renters.
Sustainable Design Features for Your ADU
Energy-Efficient Windows and Insulation: To minimize heating and cooling costs, consider investing in energy-efficient windows and insulation. This will help keep your ADU comfortable year-round without putting unnecessary strain on your HVAC system.
Solar Panels: Installing solar panels on your ADU roof can help offset electricity costs and reduce your environmental impact. California offers incentives for solar installation, which can help lower the upfront cost.
Water Conservation: California is prone to droughts, so incorporating water-saving features like low-flow faucets, toilets, and drought-tolerant landscaping can help conserve water and reduce your utility bills.
Sustainable Materials: Choose building materials that are environmentally friendly and sustainable. For example, bamboo flooring, recycled metal roofing, and reclaimed wood can all help reduce your ADU’s environmental impact.
What to Remember
Building an ADU in Millbrae can be a great way to add value to your property and create additional living space for family members or renters. However, it’s essential to carefully consider zoning regulations, permits, costs, construction timelines, and sustainability factors before embarking on your project. By taking the time to research these key elements and working with professionals who understand the local requirements, you can ensure that your ADU is built successfully and meets your long-term goals.
Ultimately, building an ADU in Millbrae can be a rewarding investment, providing both immediate and future benefits in a city that continues to grow in demand for housing.
