ADU Plans, Design and Permitting Services
Before anyone frames anything you need drawings a city will stamp, and a growing set of firms sell that and nothing else. Some sell permit-ready plan sets a jurisdiction has already reviewed, priced from a couple of hundred dollars to a few thousand. Some are architects who work only on accessory units. Some run the permit application for you at a flat fee. Buying this separately makes sense when you have a contractor you trust but no drawings, or when you want your setbacks confirmed before committing real money. The firms here quote a fixed fee, name the jurisdictions they know, and hand over drawings you own outright. We rank on fee transparency, jurisdiction coverage, and turnaround.
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A BIM and construction technology firm specializing in permit-ready ADU design across California. Offers custom plans, 3D modeling, and site feasibility studies from a $2,000 starting point, with offices spanning Los Angeles to San Francisco.
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Ready-to-build ADU plans with complete Revit BIM files, 3D renderings, and contractor-ready packages starting at introductory prices. No custom design fees needed.
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California-wide residential drafting firm specializing in ADU design, custom homes, and Title 24 energy compliance. Serves all 58 counties with permit-ready plans and local building code expertise.
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Energy-efficient architecture firm in Salt Lake City specializing in passive house and ADU design. Offers custom architectural services with a focus on thermal comfort and sustainable building practices.
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Seattle-based architecture firm led by Josh Brincko, offering ADU design and permitting services with over 20 years of experience and a hands-on approach that bridges design and real construction realities.
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Award-winning architecture firm specializing in modern and mid-century residential design, with ADU expertise in the San Jose and Silicon Valley markets and pre-approved plan programs.
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Seattle-based architecture firm founded on principles of responsible, sustainable design, with specialized ADU expertise and offices in both Washington and California serving the Pacific Northwest and beyond.
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Bay Area architects offering three pre-designed ADU packages plus custom design. Pre-designed plans include permitting and finish selections at fixed pricing.
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ADU design and architectural planning service by Jennifer Kretschmer, FAIA, offering pre-designed plans and custom ADU design for California homeowners. Plans include complete permit-ready documentation.
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A 15-year-old California drafting firm offering permit-ready ADU plans across Santa Rosa, San Diego, and Los Angeles. Provides detailed construction drawings for detached units, garage conversions, and backyard cottages with free quote consultations.
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Sacramento-based architectural drafting firm offering pre-made and custom ADU plan packages with Title 24 compliance, serving Northern California, Bay Area, and select out-of-state projects.
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Portland-area architects offering ADU design, permitting, and feasibility analysis. Founders with 20+ years combined experience and deep local expertise in Oregon building code.
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Architecture and planning firm creating permit-ready ADU designs across California jurisdictions and Colorado, with customizable pre-approved plans to streamline permitting and reduce preconstruction costs.
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Los Angeles-based drafting firm specializing in permit-ready ADU plans and navigating LADBS requirements. Eighteen years of experience, 200+ projects across LA County.
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A Sacramento-based drafting and permitting firm serving the greater Sacramento region and surrounding Northern California communities. Specializes in ADU plan sets, garage conversions, and permit expediting with fast turnaround for code-compliant designs.
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An Irvine-based architectural firm offering ADU design and permitting services across Southern California. Provides fast, budget-friendly architectural services for accessory units, additions, remodels, and custom homes without building involvement.
Frequently asked questions
What is the difference between buying pre-designed plans and hiring an architect for custom design?
Pre-designed plans are ready-to-build packages that often come at fixed or introductory prices without extra design fees. Custom design services involve architects who create unique plans tailored to your specific site and preferences.
Do these firms help with the permitting process and energy compliance?
Yes, many of the listed firms provide permit-ready documentation and specialize in local building code expertise. Several providers also specifically include Title 24 energy compliance and permitting services in their offerings.
Can I find designers who specialize in specific regions or states?
Many firms focus on specific areas, such as those serving California, the Bay Area, or Seattle. You'll find specialists covering various locations including the Pacific Northwest, Salt Lake City, and parts of Oregon.
How much should I expect to pay for ADU plans?
Prices vary widely depending on the service type. Some providers offer introductory pricing for ready-made packages, while custom BIM and construction technology plans can start around $2,000.