LADBS pre-approved ADU plans reduce permit review time from 8 to 16 weeks down to 4 to 6 weeks. They also eliminate architectural design costs of 8 to 15 thousand dollars.
LADBS has reviewed and approved specific ADU designs in advance. When you submit a pre-approved plan, the city only needs to verify site-specific conditions (setbacks, utilities, lot coverage) rather than reviewing the entire design. Result: faster permits and lower soft costs.
LADBS maintains a catalog of pre-approved ADU plans on their website (ladbs.org). Multiple architects have submitted approved designs in various sizes (400-1,200 sqft) and configurations. NP Line Design can also submit our own designs for pre-approval on your behalf.
Pros: 50-70% faster permit review, $8K-$15K savings on architecture, proven designs that work. Cons: limited customization (can't modify floor plan), may not fit your specific lot perfectly, fewer finish options. Best for: straightforward lots with standard setbacks.
If your lot has: unusual shape, significant slope, tight setbacks requiring creative placement, or if you want a specific architectural style that matches your main house. Custom plans cost $10K-$20K more but give you exactly what you want.
We evaluate your lot first. If a pre-approved plan fits perfectly, we use it — saving you time and money. If not, we design custom plans optimized for your specific property. Either way, we handle the full LADBS permit process.
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NP Line Design (CSLB #1105249). April 2026.
“Pre-approved ADU plans through LADBS are one of the most underutilized tools in LA residential construction, and I have been using them for clients since the program launched. The 4 to 8 week time savings in plan check is real — I have tracked it across 12 projects. The catch is that the standard plans are designed for typical lots and typical configurations; if your lot has a slope, a narrow side yard, or non-standard utility connections, the pre-approved plan will still trigger corrections and the time savings evaporates. Pre-approved plans work best on flat, standard rectangular lots.”
Before committing to any pre-approved ADU plan, have your contractor or architect run a preliminary site assessment comparing the plan's required setbacks against your actual lot survey. In LA's older neighborhoods, lots are often irregularly surveyed, and what appears to be a 5-foot side yard clearance on a rough Google Maps measurement is sometimes only 4 feet 3 inches after a proper survey — enough to void the plan's site compatibility.
1. Purchasing a pre-approved ADU plan and then discovering the foundation type in the plan does not match the soil conditions on their specific lot, requiring an engineering addendum that effectively resets plan check time
2. Choosing the smallest pre-approved plan to reduce permit fees without realizing that a 100-square-foot larger unit rents for $400 to $600 more per month and would have paid for the cost difference in under 2 years
3. Not reading the LADBS pre-approved plan's required setback assumptions and then positioning the ADU on the lot incorrectly, requiring a site plan revision
ADU companies that advertise '12-week ADU build times' based on pre-approved plans are measuring from construction start, not from your first contact with them. The pre-permit phase (soils report, site plan, utility coordination) still takes 2 to 4 months even with pre-approved plans. Any promise of a complete ADU in 12 weeks from contract signing is not credible in the current LA permitting environment.
LADBS pre-approved ADU plans are architectural plan sets that have completed the plan check process and been approved for use across multiple projects. Builders using these plans submit site-specific information (lot dimensions, utility connections, soils report) but skip the full architectural plan review. This typically reduces LADBS approval time from 6 to 12 weeks to 2 to 4 weeks for qualifying projects.
LADBS-sponsored pre-approved plans range from $3,000 to $8,000 for the plan documents. Private architects and ADU companies sell pre-approved plan sets for $5,000 to $15,000. Either way, you still pay full LADBS permit fees (typically $15,000 to $30,000 for a 600-square-foot ADU) and a site-specific soils report ($2,500 to $5,000). The savings are in design time and plan check wait time, not in government fees.
No. Pre-approved plans specify foundation type (typically slab-on-grade), maximum slope tolerance, setback requirements, and utility connection methods. If your lot deviates from these parameters, you need engineering addenda that partially re-enter the standard review process. Pre-approved plans work best for flat lots with standard rectangular configurations and accessible utility hookups within 20 feet of the proposed ADU location.
Minor customizations (interior wall placement, window locations within approved openings, exterior finishes) are generally allowed without resubmission. Structural changes, foundation modifications, or exterior dimension changes typically require a plan resubmission and lose the pre-approved designation. Most pre-approved plans offer 2 to 4 standard floor plan options within each square footage tier.