Taking a piece of real estate and improving it by adding an ADU is a relatively easy form of Real Estate Development that even a novice real estate investor or homeowner can accomplish with the right guidance.
Over the course of the next 12-16 weeks I will take you along as I build a brand new 1,200 sqft ADU on a property in Hyde Park, Los Angeles. I will be sharing a step-by-step "how to" which covers the entire ADU construction process from the initial design to final inspection.
This ADU is being constructed on a property I own, and I am acting as my own General Contractor. Although I am a licensed General Contractor, the information I provide in this guide will benefit anyone who is ready to start building their own ADU, even if you have little or no experience in construction. If you have a willingness to learn and are not afraid of a little hard work, then you can build your own ADU which you can use for investment or personal enjoyment. Or both.
If you have any questions or would like to discuss your own ADU construction project, please do not hesitate to contact me with questions or comments. I look forward to sharing this process and I encourage all homeowners and investor who can add an ADU to their property to do so. Southern California needs more housing and we can help by providing additional housing options for our fellow Angelenos.
The ADU I am building will be used as a rental, so I wanted to maximize my return on investment. With that as my primary motivation I chose to design and build the largest ADU that was allowed under the City of Los Angeles' ADU Ordinance.
I wanted a 3bd/2ba ADU that I could rent for top dollar. I chose to build a detached unit because I had room in my backyard, and I thought that a detached ADU would be more desirable for a family looking for a home. And as any real estate investors knows, families tend to stay longer which equals less tenant turnover which equals less headaches and lost revenue due to tenant turnover.
Larger ADUs tend to rent for more money, and every square foot of new construction you add to your property translates into a higher resale value once you decide to sell.
Once I settled on the type and size of ADU I wanted to build the next step was to get a design in place and ADU plans and construction drawings produced.
I knew exactly what I wanted and since the ADU was only two stories I didn't need a licensed Architect to come up with a new ADU design, I simply hired an experience draftsman to prepare the plans, and Structural Engineer to provide structural calculations which are typically required.
DO NOT try to save a few dollars by hiring someone that does not have experience with ADUs, or an Architect or designer that is not familiar with the ADU ordinance in your city. An inexperienced designer, Architect, or Engineer can add months to your project timeline if they are not familiar with the ADU ordinance and how each city treats the permitting process.
It is particularly important that you hire a draftsman or architect that is experienced in designing ADUs, and experienced processing ADU plans in the city you live in.
Once the Architect is done with the ADU plans the next step is to submit the plans to the city building department and wait for their comments or approval. In my case it took the City of Los Angeles about 30 days to review my plans, and after I made a few minor corrections to the plans based on the cities feedback, I had permits in hand and was ready to start construction.
I finally had the permits complete and was ready to start building my ADU. The backyard is almost completely flat, so my engineer designed a slab-on-grade foundation for the ADU. This is the least expensive foundation to build and is perfect for an ADU foundation on a flat property. But slab-on-grade foundations require a flat surface to build on and so I went to work clearing out all the trees and vegetation that was in the footprint of my new ADU. You will see from the picture below that there was one old tree that was the biggest obstacle. A quick call to a tree trimmer I found on Craigslist and the tree was removed and hauled away $1,100. That was a bargain and much less expensive than the $3,500 I had budgeted for this line item..
The picture below shows the underground plumbing lines installed under the slab. At this point we called the city inspector to come out and approve the foundation pad and footings, and to perform a water test and approve the underground plumbing. With the inspectors blessing we back filled the sewer trenches and started progress on preparing the slab for our concrete.
The picture below shows what the foundation looks like just before we placed the concrete.
A quick note on inspections... never cover up any work until that work is seen and approved by a city inspector. So, in this case when we pour our concrete we are going to cover up the rebar, vapor barrier, and wire mesh work we performed, so it was necessary to call out the inspector before that work was covered. Once the concrete is placed into the ground the work gets covered up and there is no way for the inspector to verify we performed the work to code or the approved structural design. Always, always, always call the inspector before you cover up you work. You will see as we progress on the project that the inspector is always called out right before we cover work.
Back to pouring the concrete. The engineer called for a standard 2,500 PSI concrete and our calculations showed that we needed about 27 yards of concrete to complete the slab. We hired a skilled set of concrete finishers to place and finish the concrete. A crew of four men were able to get the concrete poured and finished in about 4 hours.
The picture below shows a progress picture of the concrete being placed into the footings and slab.
You will see in the photo below that there are bolts sticking up from the concrete slab at the perimeters of the foundation. Those bolts (called "hold downs") were installed prior to the slab being poured and will be hold the foundation to the rough framing. This is a crucial step for the structural integrity of the new home and is required wherever you build, but these bolts are especially critical in California where earthquakes can easily shake a home of its foundation.
I specifically designed this ADU to be inexpensive to build by using off-the-shelf products and traditional dimensional lumber with no Structural Steel framing or large structural beams. As such my framing crew will be able to complete the rough framing portion of this project in about 12-14 working days. My job now is to make sure the framers have the lumber and materials they need, and to make sure my windows are ordered as we'll need the windows after the rough framing is complete.
The video below shows the progress after 5 working days. It's amazing how fast a small home like this can be built with an experienced crew of framing carpenters.
And these pictures show the progress after 10 working days. At this point the crew needs to finish the roof rafters, roof sheathing, sheer walls, and perform the framing pick-up. Three more full days and the framers will be 100% complete with the rough framing portion of the project.
And here are a few pictures from four days later when the rough framing for our ADU is 100% complete.
Insider Tip : Always ask the rough framing crew to install your vinyl windows as part of their service. Most rough framing carpenters are experienced installing standard vinyl windows and will include this service for a nominal upcharge. It will be much less expensive then hiring a dedicated window installation subcontractor to come in after the framers are finished to install the windows. But this advice only applies to standard vinyl and builder-grade windows. Custom windows should be left to professional window installers.
With the rough framing now complete it is time to get the plumber, electricians, and HVAC subs started with the installation of their rough work. These trades are referred to broadly as the mechanical trades.
At this stage in the project the mechanical subs are running all their work that will be within the interior and exterior walls of our new ADU. All the water supply line, sewer drain lines, electrical wire, and HVAC supply and return lines are being installed now.
We scheduled two full weeks to let the mechanical subs complete their rough installation at which point we will need to call the city inspector back out to inspect and approve their work, at which point we'll be ready to insulate the attic and walls and begin the drywall
The MEP subs are running all their work that will be within the interior and exterior walls of our new ADU. All the water supply line, sewer drain lines, electrical wire, and HVAC supply and return lines are being installed at this point in the project.
Your building plans should contain all the MEP specifications so that the subs know where to install their work. Without good plans the subs will be bumping into each other all over the place. For example a plumber might run a waste line where an electrician is supposed to install a recessed light fixture. These issues can be kept to a minimum with a good MEP plans.
We scheduled two full weeks to let the MEP subs complete their rough installation at which point we will need to call the city inspector back out to inspect and approve their work.
If you're thinking of building an ADU anywhere in the Los Angeles contact us. We're helping homeowners just like you all over Los Angeles build ADUs and Granny Flats.