IS AN ADU IN YOUR FUTURE?
Financial and Planning Issues
Many financial and planning issues must be considered to take any construction project from a dream to reality. When considering the advantages and disadvantages of building an ADU, the most common steps the homeowner must consider include:
- Is your property eligible to construct a secondary dwelling unit (ADU)?
- Financial considerations and budgeting, including site planning and design
- Permit application submittal and fees
- ADU construction
- Utility Upgrades
- Interior Finishes and Furnishings
- Rooftop Solar System
Property Eligibility
The ONE issue that prevents the construction of an ADU on any residential lot is its eligibility for a secondary dwelling unit. In most situations, the local Planning Department will permit the construction of an ADU, provided it complies with the jurisdiction’s Municipal Code. Issues for consideration include: the proximity of the ADU to property lines (commonly referred to as Setbacks), the proximity of the ADU to the main residence, the size and height of the proposed ADU, and the ADU’s architectural compatibility with the main residence.
Financial Considerations
Building an ADU requires a long-term financial investment. Issues that bring immediate costs to your project include jurisdictional permitting fees, site preparation (flat or hillside lot), utility upgrades (in many cases, upgrade
of existing main residence electrical panel is required) and the ADU’s sewer connection to the main residence’s sewer lateral extending to the public sewer system.
Permit Application Submittal and Fees
Each city and county jurisdiction establishes building and planning fees to fund staff positions (plan reviewers, counter personnel, inspectors, etc.), to pay for the jurisdiction’s infrastructure (police and fire services, road maintenance, sewer maintenance, etc.) and school fees (funding for the construction of new schools, school staffing, building maintenance, etc.). Since these fees vary from one jurisdiction to another, only an estimate for the cost of planning and building fees may be offered. In many cases, these fees are preliminary and most likely will change before permit issuance. It’s important to note that many jurisdiction fees are based on the size of the ADU. A large ADU (e.g. greater than 650 square feet in floor area) will pay greater permit fees when compared to a smaller ADU (less than 500 square feet in floor area) based on a square footage comparison.
ADU Construction
Many contractors use national averages to estimate the construction cost for an ADU. In many instances, contractors may deliver to the property owner construction costs exceeding the contractual agreement, citing ‘unknown’ circumstances. Lamfei Lin Builders does not use national averages and will not exploit the trust established with the property owner! We offer only six ADU floor plans with known construction costs. The only variable in our published construction costs is site preparation. The client will choose a floor plan (current availability includes three plans less than 500 square feet in floor area and three plans approximately 750 square feet in floor area), which lists the costs of construction for each ADU equipped with the Premium Amenity Package (mid-range amenity package). Two other amenity packages are available – Premier (basic amenity package) and Prestige (high-end amenity package), providing a deduction (Premier) or increase (Prestige) in the published construction cost for an ADU with the Premium Amenity Package.
Utility Upgrades Since an ADU is a Secondary structure on the homeowner’s property, most jurisdictions require the ADU to be serviced with water, sewer and electricity separate from the main residence. The only exception is the sewer connection. Many jurisdictions permit the ADU to share the sewer line servicing the main residence. However, this exception must be evaluated for each ADU to determine site preparation. Also, the main residence electrical service panel may need to be upgraded to provide power to the ADU’s electrical subpanel
Interior Finishes and Furnishings
The interior of the ADU reflects the homeowner’s personality. The style of kitchen and bathroom cabinets and countertops, the type of flooring, the ornate light fixtures, the color of faucet finishes, and wall and trim paint colors are personal choices that reflect the property owner’s mood and character. To help you express your personality, Lamfei Lin Builders offers three amenity package options, each offering interior finishes and furnishings at different material quality and price levels. For further information on the Premier, Premium, and Prestige Amenity Packages, please see a complete description in the Amenity Package section on this website.
Rooftop Solar System
In the State of California, all newly-constructed single-family dwellings are required to provide a minimum amount of solar power for the residence. Since the ADU is a secondary home on the same lot as the main residence, the ADU’s required Solar Voltaic System is subject to the requirements cited in the 2022 California Energy Code, Section150.1(c)14. Basically, the minimum size for the required Solar Voltaic System is determined using the following formula:
Solar Voltaic System, kW = (ADU Floor Area x 0.894)/1000 + (1+1.51)
Using Lamfei Lin Builders 440 square feet ADU as an example, the minimum required Solar Voltaic System is:
Solar Voltaic System = (440 sq. ft. x 0.894)/1000 + (1+1.51) = 2.91 kW