ADU building process

An accessory dwelling unit, also referred to as ADU, is a supplementary living space located on the territory of the main residence. When the area of the main house is no longer enough for a big family, or if the family wants to obtain a guest house, they start thinking of their own ADU project.

The thing is that developing an entire project without professional help is almost impossible. There are numerous pitfalls that a person will definitely run into during the ADU construction process. That is why people trust developing building plans to experts — general contractors — who create accessory dwelling units from scratch.

One such general contractor company is ADU Maxx. The company has been developing ADU projects for years now — we gained skills, knowledge, and experience to suggest the best-quality building products on the market. With ADU Maxx, one can count on a well-planned and perfectly created detached ADU, an attached ADU, an ADU conversion, or any possible custom ADU that one can come up with.

Building an ADU

One has to know that building an accessory dwelling unit is a several-step procedure. Let us cover the main ones.

  • Get a Free Consultation

Consulting is a quick step that rarely occupies more than three days. Before we start the construction procedure, we want to know about the basic parameters of a desired ADU. Share your ADU plans with us: do you want it to be a new construction, or would you prefer, say, a garage conversion? What are the physical characteristics of your existing garage in this case? Are you planning to retrofit the existing utilities? Which floor plan do you expect?

We need all these pieces of information to proceed to the next step.

  • Consider financing options

Depending on the finances of a client, we come up with possible solutions. Our suggestions will help the homeowner minimize the construction costs but still receive top-quality garage conversions and detached or attached prefab ADUs.

  • Development of construction project

This step involves a feasibility study and the design lock — we visit your primary residence, explore the area and the territory where the new independent housing will be located, and lock the pricing.

  • Permitting process

We will take care of the process of getting permits for your ADU — prepare the submittal package, submit plans for the commission's approval, and invite the inspectors when necessary. When the process is pre-approved, the real work begins.

  • Building an ADU in full

We start from foundation footings — for the perfect foundation slab, we need a clear and flat surface. Then we proceed to the plumbing lines, cables, and other underground utilities. After that, we place structural rebar, or structural steel, inside the concrete footings. We also built a vapor barrier and a wire mesh to avoid over-moisturizing the footings. The city inspector checks if the works at this point are going well and allows moving on with the process of building an ADU.

ADU building final steps

Then we move to the rough framing — adding the exterior walls. This is when the client can see how real his project of an ADU is. This step lasts for approximately 2–3 weeks. After that, we proceed to rough electrical and water supply lines and the interior electrical panel establishment. Then, the roof rafters are created, the siding is set, and the exterior paint is applied. This is when we call the inspector again — he has to confirm that we follow the rules of a building code.

Then we move to the insulation — we make sure staying inside the ADU is comfortable and there is no air leakage. After that, when the final inspection is passed, we go to the most entertaining and fascinating part — the interior painting and the furniture establishment.

ADU Development Takeaway

Keep in mind that even with the clearest step-by-step guide, an inexperienced person will hardly develop the project of an ADU by himself without mistakes and problems. That is why people trust their resources to professional contractors, who have been creating ADUs for years.

If you need a new ADU, contact ADU Maxx company. On our team, there are qualified designers, builders, and law and finance specialists who are ready to support you on the path of ADU creation.

Frequently Asked Questions — FAQ

What's one drawback of an ADU?

A possible drawback of creating an ADU is its price. The cost of an ADU might reach 400 thousand dollars. Yet, if you plan to build a standard ADU, 100 thousand dollars will be just enough. Anyway, the final price completely depends on the desires of house owners.

Do I need a permit to build an ADU in California?

To create your personal ADU in California, you do need building permits. The amount and nature of these permits depend on the area you live in. For instance, people from a "coastal" zone and residents of a "landslide" zone will have to address different establishments and receive different permits.

How do I start with ADU?

The simplest way to start with ADU is by contacting local general contractors. You can communicate with more than one company and pick the best.

How long does it take to build an ADU in California?

The average time California residents spend on building their ADUs is approximately four months. Yet, the length of the ADU process might vary depending on the complexity of the project and the time that getting the required permits takes.

What is the new ADU law in California?

According to the new rules, local municipalities cannot establish the minimal size of an ADU and its lot coverage. Besides, if your ADU is 750 square feet or smaller, you do not have to pay the impact fees, which usually include the costs of providing water, electricity, and other services.

How much does it cost to build ADU in California?

In California, the price of a square foot of a prefab ADU might vary between 3 and 6 hundred dollars. It mainly depends on the city where a person has property and wants to create his own accessory dwelling unit, on the builder, and on the materials.