How Long Does It Take To Build An ADU

How Long Does It Take To Build An ADU in Los Angeles
by:admin July 29, 2025 0 Comments

How long does it take to build an ADU in Los Angeles? Like any construction project, an accessory dwelling unit (ADU) build can have a timeline that varies based on a client’s specifications. An ADU’s size, location, and layout will all impact the timeline for this project. In addition to poor planning or working with an inexperienced contractor, there are many factors that can result in delays.

 

CONSTRUCTION TIMELINE 

On average, the full timeline for building an ADU can be be tracked in three parts. The first is design, the second is permitting, and the final is construction. Design can take two to six weeks depending on the size and scope of the project. Permitting can take anywhere from two to six months on average. This greatly depends on what city the ADU is located, the quality of the plans submitted, and the responsiveness of the city staff. Construction itself takes anywhere from 2 months for smaller garage conversions to six months for larger standalone ADUs.  Although these ranges vary quite a bit, the average ADU takes seven to nine months to design, permit, and build. Building an ADU should be viewed as a process with many separate steps that all require their own timeframes and attention to detail. 

Consultation and Planning

In general, the consultation and planning phase for building an ADU lasts between one to two weeks. During this period, the client and their contractor will cover things like feasibility, project scope, and site plans. In addition to meeting in person, the client and contractor will also communicate regularly to prepare to move into the design phase. This will also be a time for the client to get their financing for the project approved.

Design

The design phase for building an ADU varies greatly depending on the scope of the project along with where the project is geographically located. The reason for this variance is the complexity of the design along with the level of engineering required to complete a full drawing set for submission to the city or authority having jurisdiction. As a general rule of thumb, garage conversion take three to four weeks to design and engineer and ground up or attached ADUs take four to six weeks to design and engineer. A contractor and their associated designers and engineerings will design the overall floor plan for the ADU and, once approved by the client, will complete the engineering drawings for that specific structure. Once complete, the architectural and engineering drawings and combined into one set and submitted to the city / authority having jurisdiction where the ADU is located for review and approval. 

Permitting

In total, the permitting process for ADUs in Los Angeles can take anywhere from eight weeks to six months. This delta and large gap in potential permitting time has much to do with the scope and project size as well as the exact area of Los Angeles the ADU is located in. While permitting in the Los Angeles area for all types of construction projects is notoriously slow, people building ADUs do have an advantage. As part of an effort to tackle the city’s housing shortage, Los Angeles has streamlined the permitting process for ADUs in order to shorten construction times and reduce problems for property owners seeking to add ADUs to their properties. Hiring the right contractor and designer or architect ensures that your project’s approval is achieved as quickly as possible. 

Construction

In general, the construction phase for an ADU is between two and three months for garage conversions and four to nine months for standalone ADUs. The larger variance for construction of standalone ADUs is based on the size and whether the ADU is a single or two-story space. 

 

RELATED:  ADU Cost in Los Angeles

 

CAUSE OF ADU DELAYS

There are some factors that are simply unavoidable when planning a construction project in Los Angeles. For example, material shortages or wildfires can force crews to pause on projects. However, the truth is that most ADU builds go completely smoothly while remaining 100% on target with the timeline. This is especially true when property owners hire the right contractor to oversee the process from start to finish. 

Poor Permitting Process

It’s so important to work with a contractor with experience with going through the permitting process for ADUs in Los Angeles. Even experienced builders who do large numbers of residential or commercial projects around the city may not have the expertise necessary to sail through the unique permitting process for ADUs. With permitting, one mistake or missed deadline can lead to three steps back in the building process.

Labor and Material Shortages

While this is becoming less common as we get further away from Covid-era shortages, contractors do sometimes struggle to source certain building materials. In addition, it is sometimes difficult to find enough skilled workers to fulfill the needs of all of the various building projects going on in the city at any given time.

Plan or Design Changes

Delays from plan or design changes can happen in two ways. First, the client may simply change their mind about plan details in the middle of the project. The second way is that a previously unknown or undisclosed issue may prevent a contractor from carrying through with the original plan because of everything from challenges with the site’s terrain to permitting issues.

Utility upgrades

In some cases, ADU utilities are simply connected to the utilities used by the existing home on the property. However, new connections for sewers, water lines, and main service panels may need to be established if the existing utility infrastructure is insufficient for the load that the new ADU will add. Utility upgrades can increase both the cost and time of a project.

 

BUILD YOUR LOS ANGELES ADU

An ADU offers an incredible way to maximize the value and usability of your existing property in Los Angeles. The best news of all for Los Angeles property owners is that the city is extremely welcoming to the idea of ADUs. This can make permitting and zoning much easier compared to other types of builds. As a leading ADU builder in Los Angeles, Socal Upgrades is here to walk you through the process with ease. Book a consultation and let us bring your ADU idea to life.

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