# Detached ADU vs Garage Conversion vs Junior ADU [Browser-friendly HTML version](https://www.remodelyourvibe.com/website-guide/pages/articles/detached-adu-vs-garage-conversion-vs-junior-adu/index) Source: https://www.remodelyourvibe.com/articles/detached-adu-vs-garage-conversion-vs-junior-adu Last modified: 2026-08-08T00:00:00.000Z Text part: 1 of 1 [Full website text index](https://www.remodelyourvibe.com/llms-full.txt) | [Articles and guides](https://www.remodelyourvibe.com/llms/articles-003.txt) | [Previous page](https://www.remodelyourvibe.com/llms/pages/articles/gas-vs-wood-burning-fire-pit-california/index.txt) | [Next page](https://www.remodelyourvibe.com/llms/pages/articles/pool-remodel-vs-new-pool-southern-california/index.txt) --- 1. 1. [Resources](https://www.remodelyourvibe.com/articles) 1. [ADUs & Conversions](https://www.remodelyourvibe.com/articles/category/adus-conversions) 1. Detached ADU vs Garage Conversion vs Junior ADU [ADUs & Conversions](https://www.remodelyourvibe.com/articles/category/adus-conversions) ### Detached ADU vs Garage Conversion vs Junior ADU Costs run $60,000 to $400,000, but setbacks, utilities and Title 24 decide which one fits. [Remodel Your Vibe Design Team](https://www.remodelyourvibe.com/our-approach) August 8, 20264 min read Image: Detached ADU vs Garage Conversion vs Junior ADU: Which One Fits Your Lot In this article 1. What each path costs, per square foot 1. What the code allows on each path 1. Title 24, utilities and the hidden line items 1. Construction timeline and living through it 1. Which one to build A detached ADU in Los Angeles costs $150,000 to $400,000 and up. A garage conversion costs $80,000 to $180,000. A junior ADU, carved out of the existing house and capped at 500 square feet, costs $60,000 to $140,000. Per square foot, that is roughly $350 to $550 for detached new construction, $200 to $350 for a conversion and $150 to $280 for a JADU. Price is only half the decision. Setbacks, existing structures, utility capacity and Title 24 determine what is actually buildable on a given lot. Here is how to work it out. In this article 1. What each path costs, per square foot 1. What the code allows on each path 1. Title 24, utilities and the hidden line items 1. Construction timeline and living through it 1. Which one to build #### What each path costs, per square foot A detached ADU is ground-up construction and prices like it: $350 to $550 per square foot, so a 600 square foot one-bedroom is $210,000 to $330,000 and a 1,000 square foot two-bedroom is $350,000 to $500,000. That covers foundation at $18 to $30 per square foot, framing, a full envelope, a new kitchen and bath, a mini-split system and finishes. A garage conversion of a standard 400 square foot two-car garage is $80,000 to $180,000: the shell exists, so money goes into a new slab or slab repair, foundation upgrades where the existing footing is inadequate, insulation, windows, replacing the garage door with a wall, and full kitchen, bath and mechanical work. A junior ADU carved from existing conditioned space (often a front bedroom with its own entrance) is $60,000 to $140,000 because there is no foundation or envelope work, only a new entry, an efficiency kitchen and possibly a bathroom. Pro Tip Get a rough cost per square foot for all three paths before you fall in love with a floor plan. The plan follows the budget, not the other way round. #### What the code allows on each path In Los Angeles, ADUs are governed by Ordinance 186,481 and LAMC 12.22 A.33, layered over state law. In broad terms, state law allows a detached ADU with modest side and rear setbacks (commonly four feet) and at least sixteen feet of height, with additional height permitted in certain circumstances. A garage conversion is generally allowed to keep the existing structure's setbacks, which is the single biggest advantage of that path on a tight lot: a garage sitting on the rear property line can often become living space where new construction could not. A junior ADU is capped at 500 square feet, must be created within the walls of the existing single-family dwelling, may include an efficiency kitchen and may share a bathroom with the main house, and carries an owner-occupancy requirement. Hillside lots additionally fall under the Baseline Hillside Ordinance 184,802, and properties in the Coastal Zone need a Coastal Development Permit. Ready to Start Your Project? Schedule a free consultation with our design team. [Book a Consultation](https://www.remodelyourvibe.com/contact-us) [Call 818-300-2393](tel:+18183002393) #### Title 24, utilities and the hidden line items This is where budgets break. A new detached ADU is treated as new residential construction under California Title 24 energy standards, which brings the full envelope, mechanical and solar photovoltaic requirements with it. Converting existing space generally follows a lighter alteration path, which is a meaningful cost difference and a common reason a conversion pencils where a detached build does not. Utilities are the other hidden category. A 200 amp panel upgrade runs $3,500 to $8,000 and is required more often than not on houses built before the 1980s in Van Nuys, Highland Park or Downey. A new sewer connection or lateral work runs $4,000 to $12,000. A separate water meter, where a jurisdiction requires or the owner wants one, adds several thousand. On the positive side, state law does not require fire sprinklers in an ADU when the primary dwelling has none, a genuine saving on older housing stock. #### Construction timeline and living through it Speaking only to construction duration, not to plan review: a detached ADU is generally six to ten months of on-site work from foundation to final, longer with a complex site, a hillside or difficult access. A garage conversion is typically three to five months, and a junior ADU two to four months. Disruption differs more than the schedule suggests. A detached build happens outside the house, so daily life continues, but it consumes the backyard: trades, materials, a portable toilet and a stripped yard for most of a year, which matters if a pool or landscape project is planned. A garage conversion is mostly self-contained but takes your parking and storage permanently, and the loss of a two-car garage is a real cost on a street with permit parking in Santa Monica or Culver City. A junior ADU is the most invasive day to day: the work is inside your house, sharing walls with your bedrooms. #### Which one to build Build detached if the lot has genuine rear yard space, you want a full two-bedroom or a unit that stands on its own, and the budget supports $350 to $550 per square foot. It produces the most valuable and most flexible unit, and it is the only path that lets you design the plan from scratch. Convert the garage if the lot is tight, the garage is structurally sound, you can live without the parking, and you want the fastest route to a genuine independent unit at roughly half the cost. It is the highest-value-per-dollar path on most Los Angeles lots. Build a junior ADU if the budget caps out below $140,000, you have a suitable bedroom with a street-facing wall for a separate entry, and you accept the 500 square foot limit and the owner-occupancy requirement. It suits multigenerational households far better than it suits an investment plan. Pro Tip Walk the lot with a tape measure and mark the four-foot setbacks and the existing garage footprint before any design work. The buildable envelope answers most of this question by itself. #### Final Thoughts Detached ADUs cost the most, deliver the most and demand full Title 24 new-construction compliance. Garage conversions keep existing setbacks, avoid the toughest energy path and are usually the best value on a tight Los Angeles lot. Junior ADUs are the entry point at 500 square feet with an owner-occupancy condition. Start with the lot and the code, then set the budget. Where we build #### Build this in Los Angeles One team designs, permits and builds in Los Angeles. Start with the page for your project: - [ADUs & Additions in Los Angeles](https://www.remodelyourvibe.com/services/adus-additions/los-angeles) - [Plans, Permits & Design in Los Angeles](https://www.remodelyourvibe.com/services/plans-permits/los-angeles) - [Pool & Spa Remodeling in Los Angeles](https://www.remodelyourvibe.com/services/swimming-pool-spa/los-angeles) [Everything we build in Los Angeles](https://www.remodelyourvibe.com/service-areas/los-angeles) #### Frequently Asked Questions What is the cheapest type of ADU to build? A junior ADU, at roughly $60,000 to $140,000. It is carved from existing conditioned space inside the single-family dwelling, capped at 500 square feet, and can include an efficiency kitchen while sharing a bathroom with the main house. There is no foundation or envelope work. The trade-offs are the size cap and the owner-occupancy requirement. Is a garage conversion cheaper than a detached ADU? Substantially. A 400 square foot garage conversion runs $80,000 to $180,000, roughly $200 to $350 per square foot, against $350 to $550 per square foot for detached new construction. The shell and foundation already exist, and converting existing space follows a lighter Title 24 alteration path rather than the full new-construction energy requirements. Does an ADU need solar panels in California? A new detached ADU is treated as new residential construction under Title 24, which brings the solar photovoltaic requirement with it. Converting existing space such as a garage or a bedroom generally does not trigger the same requirement. This is one of the more significant cost differences between building new and converting, and it should be priced during design, not after. How long does ADU construction take? Speaking only to construction duration: a detached ADU is typically six to ten months of on-site work, a garage conversion three to five months, and a junior ADU two to four months. Hillside access, difficult utility connections and long-lead equipment extend all three. Design and plan review time sits ahead of these figures and varies by jurisdiction. Do I need to upgrade my electrical panel for an ADU? Very often, yes. Houses built before the 1980s frequently have 100 or 125 amp service that cannot carry a second dwelling with its own kitchen, water heater and HVAC. A 200 amp upgrade runs $3,500 to $8,000. Sewer lateral work at $4,000 to $12,000 is the other utility line item that regularly surprises owners. Topics - adu - garage conversion - junior adu - los angeles - cost comparison #### About the author Remodel Your Vibe Design Team Written by the design team at Remodel Your Vibe, a licensed ( [CSLB #1119054](https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=1119054) ), bonded and insured, veteran-owned and family-operated design-build company based in Los Angeles. Our own crews design, permit and build pools, backyards, ADUs and interiors across Greater Los Angeles and Orange County. [How we work](https://www.remodelyourvibe.com/our-approach) #### Who builds it - [CSLB License #1119054](https://www.cslb.ca.gov/OnlineServices/CheckLicenseII/LicenseDetail.aspx?LicNum=1119054) - Veteran-owned and family-operated - Years of experience building across Southern California - Our own crews build it. One team designs, permits and builds. #### Related services - [ADUs & AdditionsConvert the garage, build a backyard ADU or add a second story.](https://www.remodelyourvibe.com/services/adus-additions) - [Plans & Permits ServicesFrom first sketch to permit in hand, we handle the drawings and the city.](https://www.remodelyourvibe.com/services/plans-permits) - [3D Design ServicesSee your pool, backyard or remodel in 3D before we break ground.](https://www.remodelyourvibe.com/services/3d-design) #### Talk it through with us Discuss your project with our design team and get expert advice. We call you back within one business day. [Book a Consultation](https://www.remodelyourvibe.com/contact-us) [818-300-2393](tel:+18183002393) #### Ready to Transform Your Space? Let's discuss your vision. Schedule a free consultation with our design team and see how we can bring your project to life. [Book a Consultation](https://www.remodelyourvibe.com/contact-us) [818-300-2393](tel:+18183002393) We call you back within one business day. #### Continue Reading [All Articles](https://www.remodelyourvibe.com/articles) - [ADUs & Conversions ADU Cost in California: Complete 2026 Breakdown 12 min read](https://www.remodelyourvibe.com/articles/adu-cost-california) - [ADUs & Conversions Garage Conversion Ideas: Studios to One-Bedrooms 8 min read](https://www.remodelyourvibe.com/articles/garage-conversion-ideas) - [ADUs & Conversions ADU Construction in Pasadena: Costs, Rules & Design Ideas 8 min read](https://www.remodelyourvibe.com/articles/adu-construction-pasadena) #### Further Reading ##### Local Guide - [Granada Hills ADU Costs: Garage vs DetachedA detached ADU in Granada Hills runs $180,000 to $400,000. A garage conversion runs $95,000 to $180,000. Lot depth is generous here, but 1950s electrical service and septic pockets change the math.](https://www.remodelyourvibe.com/articles/granada-hills-adu-guide) - [Hillside Home Construction Costs in Los AngelesLA hillside construction requires specialized engineering and permits. Costs run 30-50% higher than flat properties.](https://www.remodelyourvibe.com/articles/hillside-home-construction-los-angeles) - [Building an ADU in North Hollywood and Van NuysADUs in North Hollywood and Van Nuys run $95,000 for a garage conversion to $380,000 for a detached two-bedroom. The lots are tight, the housing stock is old, and the utilities are the story.](https://www.remodelyourvibe.com/articles/valley-adu-build-guide-north-hollywood-van-nuys) ##### Comparison Guide - [Second Story Addition vs Building Out: Which Costs LessBuilding out runs $350 to $500 per square foot. Going up runs $450 to $700. Here is when the cheaper option is actually the wrong one, and what drives each number.](https://www.remodelyourvibe.com/articles/second-story-addition-vs-building-out) ##### Process Guide - [Garage Conversion to ADU: The Step-by-Step BuildA garage conversion runs $80,000 to $180,000 in Southern California. Here is the real sequence, from slab testing and plan check to the raised floor, the mini-split and final sign-off.](https://www.remodelyourvibe.com/articles/garage-conversion-adu-step-by-step) ##### Cost Guide - [Garage Conversion Cost in Santa Clarita: Line-Item PricingGarage conversions in Santa Clarita run $80,000 to $180,000, with most landing at $105,000 to $150,000. Here is the phase-by-phase cost and what HOA review and Valley heat add locally.](https://www.remodelyourvibe.com/articles/garage-conversion-cost-santa-clarita) [All ADUs & Conversions guides](https://www.remodelyourvibe.com/articles/category/adus-conversions) --- End of text part 1 of 1. This page is complete.