How To Build ADU in Los Angeles, CA

How to Build Accessory Dwelling Units (ADU) in Los Angeles

Accessory Dwelling Units became easier to build after the passing of Senate Bill 1069 in Los Angeles, CA. This made an entry to a huge number of people across Los Angeles to plan and build ADU’s on their property in an easier way without any complications. The main agenda of this law is to escalate the housing prices in Los Angeles and bring in more number of secondary housing units which are affordable.

The term granny flat construction have been acquired by Accessory Dwelling Units for the reason these are mostly built on the property targeting elderly parents. However, real estate agents along with lawmakers state that rent of these secondary housing units is too high which makes everyone unable to afford these units in present days. According to the executive director of San Diego Housing Federation Steve Russell, it is one of the modest steps. He also adds that whatever is added to the housing supply will just contribute its part to the solution, that is a big drop in the bucket, anyhow it is just again a single drop in the bucket.

Bill Cavanaugh, USModular Inc stated that Accessory Dwelling Units are one of the cost-effective ways that are built in the property and that will also add square footage for family members. At the same time even there will be an offset on the rising costs of homes which are present in Los Angeles County. A typical and simple plan of an 850 sq.ft secondary housing unit consists of a kitchen, living room along with 2 bedrooms and bathrooms that are not only affordable for the house owners but at the same time managing them is also an easier task.

The major and most important points that are included in Senate Bill 1069 are as follows:

  • ADU aka granny flats should not cross the size limit of 1,200 sq.ft.
  • ADU aka secondary housing units are just a standalone unit or can be a converted garage.
  • Parking requirements are reduced thereby benefiting in meeting several variables.
  • Charges collected on necessities such as water, sewer, or utility connection is reduced.
  • ADU’s are permitted to be built with modular construction or site built or even as a manufactured home.
  • In case if the main property does not include sprinklers, then there is no mandatory to consist of fire sprinklers.
  • Necessary to meet the requirements of ADU plus main residence local zoning floor area and Set Backs.

Even though Senate Bill 1069 has streamlined the process by reducing the fees on necessities and parking requirements, there is no point to escape from the rules of local building departments. Also necessary to submit the applications as well as plans to these departments before building ADU. To determine the feasibility factor from the zoning and financial standpoint, USModular brings in a feasibility study with a conceptual budget service which helps the house owners to plan strategically which points the size, location and cost of ADU.

Studies of USModular Inc Accessory Dwelling Unit Feasibility have formed two phases which include the following services.

1st Phase: Feasibility Study with Conceptual Budget

ADU design in Los Angeles

  • Reviews of Local Building Department Rules and Regulations will determine:

Floor Area Ratio, Setbacks, Parking, Mass Transit Plan, Available Utilities and Needs analysis 

  • Necessary to plan the requirements that need to be submitted.
  • Design the site plan of the current house.
  • Conduct analysis on the conversion of existing garage to ADU or on the new construction for ADU.
  • Essential to developing a conceptual budget for either garage conversion or else a new construction.

Only when feasibility studies with the budget are agreed by the client, then a construction contract is created and proceeds to phase 2.


2nd Phase: New Construction

  • A pre-designed Accessory Dwelling Unit or custom design ADU that is affordable can be chosen.
  • Then the type of Construction needs to be determined whether it is a site Build, Modular or Manufactured.
  • Civil Engineering Plans and House plans need to be created.
  • The site and house plans need to be submitted to State and local building departments for approvals.
  • Demo/Grade
  • Essential and basic utilities need to be installed.
  • The foundation needs to be built.
  • Then Home or Install Modular or Manufactured Home will be built.
  • It is necessary to coordinate with the State and local building department for inspections.
  • According to the plans exterior site work or landscaping needs to be completed.
  • Necessary to obtain Certificate of Occupancy


  •  The minimum cost of Accessory Dwelling Units starts at $ 110/ sq. ft *2 
  • ADU sites are built or converted based on design, finishes and code.  
  • Accessory Dwelling Units are permitted to build in cities like Los Angeles County for the reason to increase affordable housing opportunities both for families or for rental properties. 
  • Floor area along with setbacks will be dictated as per the Local jurisdiction. However, State law typically dictates parking and connection fees. 

To receive a perfect floor plan and get more information, You can contact us or schedule call for ADU construction management in Los Angeles.