The New 2021 Orange County Granny Flat and Garage Conversions Guide

Everything You Need To Know About Granny Flats and Garage Conversions in Orange County

An ADU (see ADU definition here) is an accessory dwelling unit, otherwise referred to as a granny flat, additional dwelling unit, or garage conversion. It can be defined as a second living unit on a residential lot additional to the main home or multifamily building.

In California and Orange County specifically, ADU ‘dwelling units’ have been getting a lot of interest because the state has drastically removed the major restrictions around building ADUs. And this has led to many homeowners considering building such units in their backyard or converting their garage into an ADU.

Here at GreatBuildz, a free service that personally matches homeowners in Los Angeles, Orange County, Ventura or San Diego with reliable general contractors, we talk to homeowners every day about granny flat, ADU, and garage conversion projects – here are some key points to know.

California State Granny Flat Law Changes for 2021

First off, you need to be aware of the latest rules & guidelines that have recently gone into effect to make accessory dwelling units truly viable for many Orange County homeowners. The state of California wanted to help assuage the housing crisis and therefore has required all cities to reduce local restrictions to building ADUs.

The below regulations have been passed at the state level, so be aware that every city in Orange County will approve their own specific set of guidelines, based on these latest changes. You must check with your Planning Department staff about specific guidelines and restrictions that apply to you.

  • Increased the maximum size of ADU allowed
  • Allowed ADUs on all single-family properties, no minimum lot size requirement
  • Allowed ADUs on multi-family properties 
  • Allowed different types of ADUs – detached, attached, garage conversion, second story
  • Reduced setbacks for ADUs to rear/side property lines to 4 feet
  • Waived or reduced impact fees in some cases
  • Allowed ADUs to be used as rental units for a tenant
  • Stipulated that local HOA/CC&Rs cannot restrict building ADUs
  • Parking –ZERO parking required for ADUs in many cases, as long as the home is within 1/2 mile from any transit stop.
  • City approvals – ADUs and garage conversions, in most cases, don’t require any city approvals.  You don’t need approvals from city planning dept, neighbors, planning boards, etc, as long as you’re plan is within the city guidelines. Building an accessory dwelling only requires submitting building plans to the building department and going through the plancheck process to get a building permit.

Each city in Orange County is creating its own unique rules that generally follow the State’s laws, but each will likely have their own specific differences. We have provided resources to all Orange County city’s ADU guidelines at the end of this article.

What kind of ADUs are there?

There are generally two options for a granny flat: either building a new free-standing unit in the backyard or converting an existing garage to an ADU.

A garage conversion is the most cost-effective choice because the basic garage structure already exists. The downside could be the size – most garages are usually 300-400 square feet. This is still large enough for a ‘studio’ or a small 1 bedroom space with both a kitchen and bathroom. It’s cost-effective because the ’bones’ of the structure already exist including the slab, exterior wall, roof, etc.

A newly built ADU can be in one of a few forms. It can be attached to the main home, attached to a detached garage, or fully detached. It can be one or two stories, and usually have a maximum height of 25 feet, though in some cases height may be limited to only 16 feet. It will be located in the backyard or sideyard and not in front of the main residence. Some homeowners have even built a granny flat above their existing garage.

A new detached granny flat can be a maximum of 1,200 square feet in size. A 400-600 square foot ADU is good for a one-bedroom unit and a 600-1,200sf structure can be to be up to three bedrooms and two or three baths with one or two stories.

Granny Flat ADU in Orange County

Why build a granny flat on your property?

Many people are excited about the new rules and guidelines and are exploring the possibility of building an ADU on their lot, but why?

It comes down to two things: the ability to add living space to their property and the tremendous variety of potential uses of an accessory dwelling unit.

Adding space to a home previously meant building an ‘addition’ or second story, which can be difficult. Not only was it costly, time-consuming, and required changes to the layout of your home, but it also meant living with the dust & chaos of construction in your home. In some cases, such as adding a second story, the homeowners would have to move out of the house for an extended period of time during construction.

An ADU solves for these issues and allows for a lot of flexibility. Homeowners are building them as extra space (a dedicated office or a guest house), a music or yoga studio, a mancave or she-shed, or a separate home for retired parents or post-college kids. Because an ADU has both a kitchen & a bathroom, it can always function as its own separate living space.

In addition, homeowners may also use them as a rental unit for additional income. We’ve also witnessed several retired homeowners build an ADU so they can move into it (to downsize) and rent out their primary residence as a source of retirement income. That’s pretty smart. Orange County rental rates are at historic highs, so people are seeing really great cash flow by renting their ADU.

How much does an ADU cost?

The cost of a granny flat will vary depending on design, options, and size.

As discussed, the most cost-effective version is a garage conversion to an ADU. The major structural components already exist in a garage, but this conversion requires items including constructing the fourth wall (where the garage door is currently), adding interior walls, a kitchen, bathroom, flooring, etc; adding doors and windows, plumbing, electrical, HVAC, insulation, and a new waste line to the sewer lateral.

The cost for an ADU garage conversion commonly ranges $70,000-$120,000 depending on location and the homeowner’s desires. Building an ADU above a garage will be more expensive because the garage needs to be structurally reinforced to support the weight above. Costs to construct a ‘ground-up’ new ADU will vary considerably based on size, number of stories, location, access, etc, but will often be in the $100,000-$400,000 range.

A good rule of thumb is to assume $300-$400 per square foot – and the bigger the unit, the lower cost per square foot. If you’re considering building a 2-story or second story ADU, costs will go up as well.

How do I pay for an ADU?

There are several ways to finance an accessory dwelling unit project.

Of course, homeowners can pay for it from their own savings, which is most common. They can also finance this project with a home equity line of credit, a construction loan, a cash-out refi, or a home renovation loan which offers a quick processing timeline, but does come with a higher interest rate, from a company like Lightstream or SoFi.

If you’d like a deeper analysis, I’ve written about this topic in greater detail in the following article: https://www.greatbuildz.com/blog/adu-financing-guide-los-angeles/

How long does it take to build a granny flat?

There are 3 primary stages in the ADU process: plan development, city approvals/permitting, and construction.

The overall timing depends on whether you are doing a garage conversion or building a new ADU. For a garage conversion, expect the entire process to take about 3-6 months, which includes the time to design the plans, time for the city to do the plancheck, and the construction process – which usually takes about 2-3 months.

A new ADU will take longer for the construction, so you can expect the entire process to last 6-9 months, with the construction phase taking 3-6 months.

Granny Flat ADU in Orange County

What is the process of building an ADU?

This process starts with a homeowner meeting one or more general contractors, who will come to your home to discuss the project and give some guidance about the constraints, size, design, estimated costs, etc. The contractor can give you a very rough budget of costs at this point.

Once the owner and contractor decide on the basic plan, they will bring in an architect or plan designer to start the architectural plans. Once the plans are done and approved by the owner, the contractors will prepare accurate, detailed estimates.

Next, the owner will choose their favorite contractor and sign a contract for the work. The architect will submit the plans to the building department for plan check and coordinate this process until a building permit is ready. Finally, construction can start.

Finding The Right Team – How do I hire a good ADU contractor?

When you’re looking to build a granny flat, it’s important to look for only local, licensed General Contractors. No others are qualified to do this type of major construction and using an unlicensed contractor or handyman could be a big mistake. Only reputable general contractors have the right licensing and insurance to build such a major project.

Any contractors you speak with, always confirm they have experience with accessory dwelling units. It’s best to hire a contractor who has built ADUs and garage conversions and knows the potential pitfalls and solutions.

There are some other criteria you should use in selecting a contractor, not including their price…

Things to look for in a contractor:

 

  • Valid & current contractor’s license:

It’s extremely important to check a contractor’s license on the Contractors State License Board website to confirm it is active, there are no disciplinary actions, and they have Workers’ Compensation insurance (assuming the GC has employees).

  • Insurance:

Always get a copy of a contractor’s insurance certificate and make sure it’s not expired. It might be a good idea to call their insurance broker and ask if they’ve had any insurance claims against them. There have been cases where uninsured contractors have ‘photoshopped’ their insurance documents to trick homeowners, so you can never be too careful.

  • Check their references:

Ask every contractor for at least three references that you can call. It’s important to call these folks and ask about their experience and satisfaction with the contractor’s quality, schedule, and communication skills. If you can get some pictures of the work, that’s helpful too. Or you can visit a project the contractor recently completed to gauge the quality of the work.

  • Read online reviews:

It’s a good idea to do a Google, Yelp, and Social Media search of the contractor to check for any negatives or red flags. Read all reviews you can find about their business, keep an eye out for fishy or fake-sounding reviews, and make sure to address any issues you found with the contractor. I’ve written a detailed article specifically on the topic of hiring an ADU contractor. If you’re currently in the process, take a look at it here: https://www.greatbuildz.com/blog/find-an-adu-contractor-10-tips/

At GreatBuildz, we take contractor screening seriously. We take all the steps above, in addition to running a background/financial check and requiring contractors to sign our 20-point Code of Conduct.

 

Feel free to call our free service and our friendly staff will match you with several fully vetted, honest contractors in Los Angeles, Orange County, Ventura or San Diego who are experienced with ADUs. For more info, visit www.greatbuildz.com or call 818.317.3567 today.

Granny Flat Guidelines for Every City in Orange County

https://legistarweb-production.s3.amazonaws.com/uploads/attachment/pdf/589476/Staff_Report__10_.pdf

https://www.codepublishing.com/CA/AlisoViejo/html/AlisoViejo15/AlisoViejo1514.html#15.14.080

http://caladu.org/ordinance/aliso-viejo-12-15-2017.pdf

https://www.housable.com/city/aliso-viejo-ca-109934 

https://anaheim.net/DocumentCenter/View/32105/ADU-Ordinance-6483?bidId=

https://codelibrary.amlegal.com/codes/anaheim/latest/anaheim_ca/0-0-0-67963

https://www.housable.com/city/anaheim-ca-109178 

https://www.ci.brea.ca.us/1377/ADU-FAQ

http://weblink.cityofbrea.net/WebLink/0/doc/120780/Page9.aspx

https://www.housable.com/city/brea-ca-109094 

http://www.buenapark.com/home/showdocument?id=17461

https://qcode.us/codes/buenapark/view.php?topic=19-3-19_348-19_348_010&frames=on

https://www.housable.com/city/buena-park-ca-109218 

https://www.costamesaca.gov/home/showdocument?id=30224

http://qcode.us/codes/costamesa/view.php?topic=13-v-1-13_35

https://www.housable.com/city/costa-mesa-ca-109745 

https://www.cypressca.org/government/departments/community-development/planning-division

https://www.cypressca.org/work/building-division

https://www.housable.com/city/cypress-ca-109219 

  • Dana Point ADU Guidelines

https://www.danapoint.org/home/showdocument?id=29471

https://www.danapoint.org/Home/ShowDocument?id=31056

https://www.housable.com/city/dana-point-ca-109749 

  • Fountain Valley ADU Guidelines

https://www.fountainvalley.org/DocumentCenter/View/9464/Accessory-Dwelling-Unit-ADU-Development-Standards

https://www.fountainvalley.org/1353/Accessory-Dwelling-Units-Documents

https://www.housable.com/city/fountain-valley-ca-109714 

  • Fullerton ADU Guidelines

https://www.cityoffullerton.com/government/departments/community-and-economic-development/planning-zoning/zoning/accessory-dwelling-units-granny-units?locale=en

https://maxablespace.com/adu-regulations/fullerton-adu-regulations/

  • Garden Grove ADU Guidelines

https://ggcity.org/planning/adu

https://ggcity.org/city-files/ADU-New-Construction-English.pdf

https://www.housable.com/city/garden-grove-ca-109681 

  • Huntington Beach ADU Guidelines

https://www.qcode.us/codes/huntingtonbeach/view.php?topic=zoning_code-23-230-i-230_10

https://www.huntingtonbeachca.gov/government/departments/planning/

  • Irvine ADU Guidelines

https://library.municode.com/ca/irvine/codes/zoning?nodeId=ZOOR_DIV3GEDESTLAUSRE_CH3-26ACDWST_S3-26-7ADREACDWUN

https://irvinewatchdog.org/wp-content/uploads/2020/05/ADU-ZO-UPDATE-5_7-pc.pdf

https://www.housable.com/city/irvine-ca-109407

https://www.lahabracity.com/DocumentCenter/View/10165/Urg-Ord-1813-ADU-PDF

https://lahabra.granicus.com/MetaViewer.php?view_id=2&clip_id=345&meta_id=37843

http://qcode.us/codes/lahabra/view.php?topic=18-i-18_12-18_12_150

https://www.housable.com/city/la-habra-ca-109742 

  • La Palma ADU Guidelines

https://library.municode.com/ca/la_palma/ordinances/code_of_ordinances?nodeId=1025706

https://www.cityoflapalma.org/DocumentCenter/View/10220/Item-10_Adoption-of-ADU-Ordinance

https://www.housable.com/city/la-palma-ca-109740 

  • Laguna Beach ADU Guidelines

http://www.lagunabeachcity.net/news/displaynews.htm?NewsID=1817&TargetID=1

http://www.lagunabeachcity.net/cityhall/cd/planning/default.htm

https://www.housable.com/city/laguna-beach-ca-109756 

  • Laguna Hills ADU Guidelines

https://www.lagunahillsca.gov/DocumentCenter/View/114/Accessory-Structure-Standards

https://www.housable.com/city/laguna-hills-ca-109782

  • Laguna Niguel ADU Guidelines

https://www.cityoflagunaniguel.org/DocumentCenter/View/783/213—Accessory-Residental-Unit-Permit 

https://www.housable.com/city/laguna-niguel-ca-109127 

  • Lake Forest ADU Guidelines

https://lakeforestca.gov/DocumentCenter/View/10336/Draft-ADU-Ordinance?bidId=

https://www.lakeforestca.gov/DocumentCenter/View/10383/Applicants-Guide-to-Submitting-ADU-Permit-7-13-20-Temp 

https://qcode.us/codes/lakeforest/?view=desktop&topic=9-9_146-9_146_050 

https://www.housable.com/city/lake-forest-ca-109034 

  • Los Alamitos ADU Guidelines

https://www.housable.com/city-adu-ordinance/los-alamitos-ca-109632 

https://www.housable.com/city/los-alamitos-ca-109632 

https://cityoflosalamitos.org/?wpfb_dl=3897 

  • Mission Viejo ADU Guidelines

https://www.codepublishing.com/CA/AlisoViejo/html/AlisoViejo15/AlisoViejo1514.html#15.14.080

https://www.housable.com/city/mission-viejo-ca-109301 

  • Newport Beach ADU Guidelines

https://www.newportbeachca.gov/trending/projects-issues/accessory-dwelling-unit-ordinance

https://www.newportbeachca.gov/home/showdocument?id=66572

https://www.housable.com/city/newport-beach-ca-109917

  • Orange ADU Guidelines

https://library.municode.com/ca/orange/codes/code_of_ordinances?nodeId=TIT17ZO_CH17.14REDI_17.14.160ACSTGAACDWUN 

https://www.housable.com/city/orange-ca-109203

  • Placentia ADU Guidelines

http://qcode.us/codes/placentia/ 

https://www.housable.com/city/placentia-ca-109173 

  • Rancho Santa Margarita ADU Guidelines

https://www.cityofrsm.org/DocumentCenter/View/6557/Accessory-Dwelling-Unit-ADU-Application?bidId=

https://library.municode.com/ca/rancho_santa_margarita/codes/code_of_ordinances?nodeId=COOR_TIT9PLZO_CH9.04RESPUSST_S9.04.190ACDWUN 

https://www.housable.com/city/rancho-santa-margarita-ca-109286 

  • San Clemente ADU Guidelines

https://www.san-clemente.org/departments-services/housing-social-services/accessorydwellingunits https://library.municode.com/ca/san_clemente/codes/code_of_ordinances?nodeId=TIT17ZO_CH17.28SPUS_17.28.270ACDWUN  https://www.housable.com/city/san-clemente-ca-109879 

  • San Juan Capistrano ADU Guidelines

http://www.qcode.us/codes/sanjuancapistrano/revisions/1046.pdf 

https://sanjuancapistrano.org/Portals/0/Documents/Development%20Services/Planning%20and%20Zoning/ADU%20Checklist%20%20Survey.pdf 

https://www.housable.com/city/san-juan-capistrano-ca-109170 

  • Santa Ana ADU Guidelines

https://www.santa-ana.org/sites/default/files/pb/planning/Counter%20Forms/ADU-JADU%20Pkt%20-%202020%20Final.pdf 

https://www.santa-ana.org/sites/default/files/pb/planning/Counter%20Forms/Accessory%20Dwelling%20Units%20Handout%205-20_0.pdf 

https://www.housable.com/city/santa-ana-ca-109619 

  • Seal Beach ADU Guidelines

http://www.qcode.us/codes/sealbeach/?view=desktop&topic=11-iv-11_4_05-11_4_05_115 

https://www.housable.com/city/seal-beach-ca-109985 

  • Stanton ADU Guidelines

http://www.qcode.us/codes/stanton/revisions/1098.pdf 

https://www.housable.com/city/stanton-ca-109697

  • Tustin ADU Guidelines

https://www.housable.com/city/tustin-ca-109926

  • Villa Park ADU Guidelines

http://villapark.org/LinkClick.aspx?fileticket=d44HlNrkTy4%3d&portalid=0&timestamp=1602279275513

https://www.housable.com/city/villa-park-ca-109804 

  • Westminster ADU Guidelines

https://www.westminster-ca.gov/departments/community-development/planning-division/accessory-dwelling-units

http://www.qcode.us/codes/westminster/view.php?topic=17-4-17_400-17_400_135&frames=on

https://www.housable.com/city/westminster-ca-109031

  • Yorba Linda ADU Guidelines

http://qcode.us/codes/yorbalinda/view.php?topic=18-18_20-ix&highlightWords=Accessory+dwelling

https://www.yorbalindaca.gov/DocumentCenter/View/218/Accessory-Dwelling-Unit-Instructions-PDF?bidId= 

https://www.housable.com/city/yorba-linda-ca-109371 

We Make It Easy To Find A Great Contractor

GreatBuildz matches you with reliable, pre-screened general contractors and takes the stress out of renovating – at no cost to you.  

GreatBuildz Guide Newsletter
  • This field is for validation purposes and should be left unchanged.

What is GreatBuildz?

Recent Posts