Accessory Dwelling Unit

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    What are ADUs, and Are They Right for You?

    ADU addition on home

    An ADU is an Accessory Dwelling Unit with complete independent living facilities for one or more persons and has few variations: 

    • Detached: The unit is separated from the primary structure 
    • Attached: The unit is attached to the primary structure 
    • Converted Existing Space: Space (e.g., master bedroom, attached garage, storage area, or similar use, or an accessory structure) on the lot of the primary residence that is converted into an independent living unit. 
    • Junior Accessory Dwelling Unit (JADU): A specific type of conversion of existing space that is contained entirely within an existing or proposed single-family residence. 

    (ADUs) have been known by many names: granny flats, in-law units, backyard cottages, secondary units, and more. No matter what you call them, ADUs are an innovative, affordable, effective option for adding much-needed housing in California. ADU’s have grown exponentially in number as more cities, counties, and homeowners become interested in ADUs as one solution to increasing the supply of affordable housing.  

    What are the benefits of ADUs?

    • ADUs are an affordable type of home to construct in California because they do not require paying for land, major new infrastructure, structured parking, or elevators. 
    • ADUs can provide a source of income for homeowners. 
    • ADUs are built with cost-effective wood frame construction, which is significantly less costly than homes in new multifamily infill buildings. 
    • ADUs allow extended families to be near one another while maintaining privacy. 
    • ADUs can provide as much living space as many newly built apartments and condominiums, and they are suited well for couples, small families, friends, young people, and seniors. 
    • ADUs give homeowners the flexibility to share independent living areas with family members and others, allowing seniors to age in place as they require more care. 

    ADU Rule Changes for California

    ADU Interior
    • Now you can add two ADUs to your property! You are now permitted two ADUs on a single-family zoned property, one full Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit (JADU) is a 500 sq. ft. max ADU created by converting part of an existing residence (such as a spare bedroom or attached garage).
    • Larger ADUs: Starting in 2020 you can now build a detached ADU up to 800 sq. ft. and 16' tall without any local discretionary approvals. ADUs created by conversions are also granted automatic approval.
    • More Parking Exceptions: Starting in 2020, ADUs do not require parking if they are created within an existing space in your house or an accessory structure, like a garage or carport. Additionally, no replacement parking is required for the main residence when a garage or carport is demolished or converted to create an ADU. 
    • Reducing Setbacks: Setbacks for new ADUs have been reduced to 4' for side and rear yards. 


    Design Permit and Construction

    • Design Phase: Imagine all the ways your ADU will be used over the years. Who will live there? How much space do they need? How fancy will it be? Will it have unique features like wheelchair access or a garden? Consider using BEST Techs Contracting to help you design your ADU and follow all the rules and refine your budget to fit the expected design 
    • Permit Phase: A new state law makes it easier, faster, and cheaper to get permits for ADU’s, but each city still has its own process. BEST Techs Contracting will visit your City’s Planning and Building Department to them what we are proposing to build, pick up forms and ask about the related fees. We are experienced professionals, and make this process easier for our clients 
    • Construction Phase: This should be the relaxing part, so kick up your feet, enjoy your afternoon drink, and watch as your new ADU appears before your eyes. If everything was spelled out in the design phase, then the building of the project will be smooth sailing for everyone involved. ADU’s are usually built in less than 90 days, so latch your seat belt and enjoy the ride. It should be fun! 
    Adu Exterior Backyard

    The Cost of Building ADUs

    ADU Construction Cost Breakdown
    Passive House Energy Use Graph

    Construction costs for your ADU (Second Unit) will vary significantly depending on personal preferences, site conditions, location, and many other factors. Similar to asking what an average wedding will cost, it is impossible to give an accurate estimate without some specifics and an understanding of your preferences. 

    The cost to develop an ADU typically ranges from $50,000 for a simple interior conversion to $500,000 for a large unit with high-end finishes on a hillside lot. Cost per square foot is sometimes a confusing way to estimate, though this too can range from $200 - $800 per square foot depending on the complexity and design finish of the project. Generally, most projects are between $250 - $500 per square foot, and $400 per square foot is a good starting estimate for an average project. 

    Now let us talk about Code Built vs. NZE and Passive House Standards. Here as you can see a chart comparison for 2019 Code Built ADU, compared to NZE and Passive House. As you can see, even though it costs slightly more to build the most durable and comfortable home you can live in, it pays for itself with the energy savings of a lifetime. 

    The Charts are from (2) different projects and climate zone-specific 

    These costs depend on the quality of products, quality of workmanship, and quality of your General Contractor. 

    Can I Build an ADU that is Energy Efficient?

    When BEST Techs Contracting build towards Net Zero Energy and Passive House Standards, then the overall prices can go up on portions of the project, due to thicker exterior walls, more insulation levels, but they go down on the smaller heating/cooling systems side, and the overall energy use of the ADU’s lifetime. 

    So, after you move into the ADU, the energy bills are reduced up to 90% of existing ADU’s, and 71% better than any 2019 new code construction ADU. 

    What does this mean for you? A home with better comfort, better indoor air quality, and a safer, more durable home that uses less energy. 

    BEST Techs Contracting is a Home Performance Contractor that specializes in Healthy, Environmentally Friendly homes, utilizing Net Zero Energy and Passive House Standards. 

    Our Story

    Best Tech ADU Illustration

    BEST Techs Contracting is a design, build and remodel firm serving Orange County Ca. We have been in business since 1990 as a husband-wife team. Jason and Penny have worked together since the beginning of their marriage to build their company as a premier construction company that views their clients as family members. 

    We know how important remodel work is and we make sure that we are continually educating ourselves on new building techniques and guidelines for a more sustainable environment. 

    Our passion is building and the pursuit of a healthier, eco-friendly living for everyone. 

    Home Performance General Contractors Specializing in Healthy, Environmentally Friendly Homes Utilizing Net Zero Energy and Passive House Standards

    What does this mean for you? A home with better comfort, better indoor air quality and a safer, more durable home which uses less energy.

    BEST Techs Contracting is a Home Performance General Contractor that specializes in Healthy, Environmentally Friendly homes, utilizing Net Zero Energy and Passive House Standards. 

    BEST Techs Contracting
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