STEPS TO BUILD AN ADU

Fastest ADU Builder in Los Angeles & Ventura County

HOW TO BUILD YOUR OWN ADU

How long does an ADU take to build? MV Design & Builder can build a standard ADU conversion in 6 weeks.

Learn how to build your own ADU. Keep up-to-date with MV Design & Builder.

will provide homeowners with tips and tricks on how to save money and what to avoid doing.

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1 - DEMO

Starting with demolition, the demo process includes removing all existing conditions, which can include illegal bathrooms, existing drywall, floors, and kitchenettes. This is the initial phase of demo. Other aspects of demo include: demolishing and hauling away garage doors, excavating under the former garage door to install a new footing, typically 12" x 24”. Ironically, Most garages in California dont have existing footings.

Many times, clients with non-compliant garages ask us to leave the existing shower stall, toilets and kitchen intact, however, local building and safety laws don't always allow this, as they want to inspect the rough and underground plumbing. Therefore, we have a pre-inspection with our resident inspector to avoid any issues before demo begins.

Demo usually takes between one and two days depending scope and size of the project.

2 - Underground Mechanical

Underground Mechanical The next step in the process is underground plumbing. This includes trenching to install new sewer lines, new gas lines, and new water lines. Usually, we must run a line to connect to our main sewer line in the front yard. Keep in mind, new sewer lines can connect to the existing lines but must be at least 5 feet away from the home. This phase usually takes 3-4 working days.

3 - Foundation

We simultaneously work on our foundation and framing elements because many times the underground plumbing must run through our new footing to reach the new proposed locations of the kitchen and bathroom. At this step you should be pouring concrete and preparing for the framing od the interior of your ADU.

4 - Framing

When designing your ADU make sure avoid using specialty lumber. Keep the ADU framing simple by using standard 2x4 and 4x4 sitting on 16 inches of wood framing. Do not over complicate the framing of your ADU, be sure to talk to your architect. I cannot stress this enough, you do not need to reengineer what an ADU is, keep it simple and use standard materials.

5 - Doors & Windows

There are three types of windows; vinyl, aluminum and clad. The way to install your windows and doors for your ADU, is to first cut the existing stucco of the garage. Remember, keep as much of the existing stucco as much as possible. This will save you money down the line because rewrapping the garage is expensive. It is important to know that you will not pass framing inspection without doors & windows installed. For the interior of your ADU you have two option; you can either install sliding doors or pocket doors.

6 - Roof

The roof for your ADU garage conversion can be the most expensive part of your ADU project. So it's important you know what conversations to have with your contractor. This specific project is unique because the homeowner had the roof done prior to wanting to build an ADU garage conversion. The roof was only 5 years old, therefore the plywood and shingles were good enough to avoid building a new roof.

Note: your existing roof condition should not have any holes, leeks and/or water damage. If there is water damage, the roof is not salvageable, you may have to demo the roof, and start from scratch (you don't want this).

7 - HVAC

If your ADU is small, I recommend installing Ductless Mini Splits. Ductless Mini Splits are perfect for 1 bedroom, 1 bathroom ADUs. If your ADU is reaching 2 bedroom, or potentially 3 bedrooms, I recommend installing central A/C system. The higher the square footage of the ADU, the more likely you'll choose Central A/C.

Condensers for your ADU can be installed outside, in the attic, or on the roof of your ADU. I personally like to install the ADU condenser on the exterior of the accessory dwelling unit, with a concrete pad. The reason that I prefer the exterior is because as they age, they shake, this will lead more maintance of the unit. AC unit also need to be a certain distance from the property line, make sure to talk to your inspector before choosing the location. Check your title 24 to ensure you install the correct condenser size.

8 - Electrical

For this ADU garage conversion we decided to upgrade the electrical panel. 1 panel is shared between the ADU and main home. The original panel was 100 AMPs and we upgraded it to 200 AMPs, 60 amps designated for the ADU. The sub panel is located on the exterior of the ADU. Make sure to talk to your inspector to clarify the sub panel location. Remember both panels must be grounded.

9 - Plumbing

You want to upgrade your gas line and add an extra shut off valve for your ADU garage conversion. Homeowners always ask me, “should we do a separate gas meter for our ADU Garage Conversion?"

We recommend doing separate gas meter because the ROI is low. For this ADU Garage Conversion we did a gas stove. You can choose between a gas stove or an electric stove at the design phase of your ADU. The sink we chose was 18 inches, giving us more counter space.

10 - Insulation

Select appropriate insulation materials based on your ADU's specific requirements and the recommended insulation values for your region. Common insulation materials include fiberglass batts, cellulose, spray foam, rigid foam boards, and mineral wool. Identify the areas in your ADU that require insulation. This typically includes exterior walls, interior walls (for soundproofing), floors, ceilings, and attics. Install insulation batts or blow insulation into the cavity of the walls, ensuring proper coverage and avoiding compression. Install insulation in the floors and ceilings of your ADU. In some climates or specific areas, the installation of a vapor barrier may be necessary. A vapor barrier helps to prevent moisture from entering the insulation. Be sure to also insulate exposed plumbing pipes and HVAC ducts in unconditioned spaces, such as crawlspaces or attics, to prevent heat loss or condensation.

11 - Drywall

Start by carefully measuring the walls and ceilings where the drywall will be installed in the ADU. Purchase the appropriate type and thickness of drywall for your ADU project. Consider factors such as fire resistance and soundproofing requirements, as well as any local building code specifications. Measure and mark the dimensions of the drywall panels according to your layout plan. If applicable, install drywall on the ceilings following the same principles as the walls. Drive drywall screws into the panels, sinking them slightly below the surface without breaking the paper. Apply joint tape over the seams between the drywall panels, embedding it in a thin layer of joint compound. Once the joint compound is completely dry, sand the seams and any imperfections using sandpaper or a sanding pole. Be careful not to over-sand or damage the drywall.

10 - Insulation

12 - Painting

Start by using painter's tape to protect trim, baseboards, windowsills, door frames, and any other areas where you want to maintain a clean, crisp edge. Prime the surfaces first! Primer helps create a smooth, uniform base and improves the adhesion and durability of the paint. Select the appropriate paint type and color for your ADU. Consider factors such as the desired finish (e.g., matte, satin, semi-gloss), the sheen level, and any specific requirements for the area (e.g., moisture-resistant paint for bathrooms). Use a small brush or an angled brush to "cut in" along the edges of the walls, corners, and trim. Then use a roller with a suitable nap length for your surface (short nap for smooth walls, longer nap for textured surfaces). Allow for drying time between coats. Once the final coat of paint is dry to the touch, carefully remove the painter's tape at a 45-degree angle. This helps achieve clean, sharp edges.

13 - Stucco

Start by ensuring that the surface you're applying stucco to is clean, structurally sound, and free from dust, dirt, oil, or any loose material. Apply a weather-resistant barrier or building paper over the substrate. Install metal lath over the weather-resistant barrier. Use galvanized or self-furring metal lath and attach it securely to the substrate using nails or screws. Mix the stucco materials, including the stucco cement, sand, and water. Apply the scratch coat, which is the first layer of stucco, to the prepared surface. Use a trowel to spread the stucco mixture over the metal lath, pressing it firmly into the lath and ensuring a consistent thickness. Let the scratch coat cure for a sufficient period. Apply the brown coat, which is the second layer of stucco, over the cured scratch coat. Lastly, apply the final layer, known as the finish coat, to achieve the desired texture and appearance. This coat can be a color coat or a textured coat, depending on your preference. Allow the finish coat to cure for the recommended period, typically 7 to 14 days, depending on weather conditions. If desired, apply a stucco sealer or paint to enhance the appearance and protect the stucco surface.

14 - ADU Bathroom

Determine the layout and design of your bathroom based on the available space and your specific needs. Consider the placement of fixtures, such as the toilet, sink, shower/bathtub, and storage areas. Ensure proper ventilation for the bathroom by installing an exhaust fan or a ventilation system. Install baseboards, trims, and moldings to complete the look. Install lighting fixtures, such as overhead lights, vanity lights, and task lighting, to provide adequate illumination in the bathroom. Tile desired area(s) according to the design plans. Install accessories such as towel hooks, shelves, shower curtains, and any other functional or decorative items to personalize your bathroom and enhance its usability.

15 - Gutter

Assess the roofline of your ADU and plan the gutter layout. Determine the optimal locations for downspouts, ensuring proper water flow and drainage away from the foundation. Measure the length of the roofline where the gutters will be installed. Mark the positions of the gutter hangers or brackets along the fascia board, ensuring proper spacing. Attach the gutter hangers or brackets to the fascia board using screws or nails. Using a hacksaw or tin snips, cut the gutter sections to the measured lengths. Connect the gutter sections using connectors or slip joints, following the manufacturer's instructions. Apply sealant to the joints to prevent leaks. Install end caps on both ends of the gutters. Again, apply another sealant to create a watertight seal. Attach downspouts to the gutter outlets or elbows. Secure them using screws or brackets, ensuring they are securely fastened to the exterior walls. Once you are satisfied with the gutter installation, secure all the components properly.