ADU Design & Blueprints in Pomona, CA

ADU Design & Blueprints in Pomona, CA

ADU Design & Permitting in Pomona means producing the full set of architectural and engineering drawings that the City of Pomona Building and Safety Division accepts for plan check – site plan, floor plan, elevations, sections, and the structural and Title 24 energy sheets that come with them. Without a complete, code-compliant set, your permit application stalls, and everything downstream – financing, construction, the tenant lease you’re counting on – stalls with it.

At Ellery ADU Studio, the blueprints are not a side product we hand off to a drafter. They are the core of what we do. Every permit set we produce in Pomona is written to the city’s current standards, coordinated with our construction scope before a single board is cut, and backed by a written price before any work begins – per Haven Standard Clause 1. If you have questions about how the blueprint phase fits into the full approval process, our ADU Design & Permitting in Pomona page walks through every stage. You can also call us directly at (657) 286-7915 – a live person picks up, no voicemail queue.

Since 2015, Nadia Ellery has led the studio through more than 900 ADU projects across Los Angeles County and the Inland Empire. Every one started with the drawings. That is where we start with you.

When You Need ADU Design & Blueprints

• You own a lot in Pomona and want to build a new detached ADU. The city requires a full architectural set showing the proposed structure, setbacks from property lines, and how the new unit relates to the primary dwelling. In most single-family zones east of Garey Avenue, the rear setback for a detached ADU is four feet from the property line – your drawings have to prove that clearance.
• You are converting your garage and the city flagged your application. Pomona’s building division routinely kicks back garage conversion submittals that are missing egress window dimensions, ceiling height documentation, or a compliant bathroom layout. A complete blueprint set resolves those flags before plan check.
• A lender or title company is asking for permitted drawings. If you want to roll ADU construction costs into a renovation loan or HELOC, most lenders want a stamped permit set, not a contractor sketch. We produce the set the underwriter needs.
• You received a contractor bid with vague line items. “Plans and permits – $8,000” on a bid sheet tells you almost nothing. Our blueprint package has a written scope, a written price, and a named list of sheets in the set – so you know exactly what you are paying for under Haven Standard Clause 1.
• You are considering a prefab or modular unit. Systems like Plant Prefab and Boxabl require site-specific drawings that marry the manufacturer’s structural assumptions to your actual Pomona lot conditions – soil class, topography, utility stub locations. That coordination lives in the blueprint set.
• Your existing ADU was built without permits and you need an as-built set. Pomona has pursued unpermitted ADU enforcement more actively since 2023. An as-built blueprint package is the first document you need to begin a legalization path.

Our ADU Design & Blueprints Process

1. Site documentation and measurement. We visit the Pomona property, measure every dimension that affects the design – lot width, existing structure footprints, setback distances, utility meter and panel locations, and any grade changes. In neighborhoods like Lincoln Park or near the Pomona Valley, lot irregularities and sloped rear yards are common; we flag those conditions in writing during this visit, not after drawings are already underway. You receive a documented photo record of everything we observe.
2. Written price before any drawing begins. After the site visit, we produce a written quote that names the sheets in the set, the fee, and the timeline – no ranges with asterisks, no “subject to change after plan check.” Under Haven Standard Clause 1, no work starts until you have that price in writing and have signed off on it. This is not a formality; it is the document that protects you if there is ever a question about scope.
3. Schematic design and owner review. We produce a schematic floor plan and site plan showing the proposed ADU footprint, access points, and basic room layout. You review it. We revise it. This is the moment to change the bedroom count, shift the entry, or decide the 500-square-foot unit makes more financial sense than the 750-square-foot version. Changes at this stage cost nothing extra – changes after construction drawings are complete cost time and money.
4. Full construction document set. Once the schematic is approved, we produce the complete permit set: architectural floor plan with dimensions and notes, elevations on all four sides, building sections, roof plan, foundation plan, and any specialty sheets the project requires (structural engineer-stamped framing plans for new detached ADUs, for example). Title 24 energy compliance calculations are included – Pomona requires them for all new habitable space. If the project involves James Hardie siding or another specific cladding system, the product specs and installation details go into the set here.
5. City submittal and plan check coordination. We submit to the City of Pomona Building and Safety Division and track the application. When plan check comments come back – and they almost always do on the first round – we respond to each comment in writing and issue revised sheets. We do not hand you a packet and wish you luck. The permit is the goal; we stay on it.
6. Permit issuance and construction handoff. When the permit issues, the approved drawings become the legal construction documents. Because Ellery operates as a design-build studio, those same drawings go straight to our construction team under the same single contract. There is no handoff gap, no “the builder says the drawings are wrong” situation. The 365-Day Done Right Promise – in writing, before the project starts – covers any deviation from the permitted drawings through construction and for a year after completion.

ADU Design & Blueprints Pricing in Pomona

How Much Does ADU Design & Permitting Cost? (2026 Price Guide) - Pomona, CA breaks down the fees for ADU projects in Pomona by unit type and complexity. Below are the typical ranges for the permit set itself – not the full project cost. These are the fees for the permit set itself – not the full project cost. Every figure below comes with a written quote before any drawing begins.

Three factors push a Pomona project toward the higher end of any range:

• Sloped lots. Properties in the north Pomona foothills near the Pomona Valley Medical Center corridor frequently have rear yards that drop two to four feet from front to back. Grading plans and retaining wall details add sheets and engineering hours.
• Existing structure conditions. If a garage slab is thinner than four inches or a foundation lacks the reinforcement required for a new story, the drawings have to document remediation. We find this in the site visit, not after submittal.
• HOA-governed properties. Some Pomona neighborhoods near Garey Avenue or Phillips Ranch have CC&R requirements that layer on top of city code. Design drawings sometimes need to satisfy both the city and the HOA architectural committee simultaneously.

If you already have a written estimate from another firm, call (657) 286-7915. We offer a free second opinion on any written bid – we will tell you what the sheet count should look like for your project type and whether the fee is within the Pomona market range.

When Ellery handles both design and construction under a single contract, the all-in cost for a complete Pomona ADU – drawings through final inspection – typically runs $180,000 - $320,000 for a new detached unit and $90,000 - $160,000 for a garage conversion, depending on size and finishes. Those numbers come with a written price before work begins, always.

FAQs – ADU Design & Blueprints

How long does it take to get ADU blueprints approved in Pomona?

Plan check at the City of Pomona Building and Safety Division currently runs six to ten weeks for standard ADU submittals, and the first-round comment response adds two to four weeks in most cases. Total time from site visit to approved permit typically lands between four and six months, assuming no major structural complications and no HOA & Zoning Compliance review layer. Projects in the Phillips Ranch area with HOA requirements have added four to eight weeks in our experience. We track every open submittal and respond to comments without waiting for you to chase us.

What sheets does a Pomona ADU permit set actually need?

At minimum, a complete Pomona ADU permit set includes a site plan showing the lot, existing structures, and proposed ADU footprint with all setback dimensions called out; floor plan with room dimensions, door and window schedules, and egress notes; four-elevation drawings; at least one building section; a foundation plan; a roof framing plan; and a Title 24 energy compliance report. New detached ADUs require an engineer-stamped structural set on top of that. Garage conversions need documentation of the existing slab thickness and any new load-bearing elements. Missing any of these sheets is the most common reason Pomona applications come back in plan check. Call (657) 286-7915 if you want to know what your specific project needs before you pay anyone to draw anything.

Can Ellery draw blueprints for a prefab unit like Plant Prefab or Boxabl on my Pomona lot?

Yes. Prefab and modular systems still require site-specific drawings for Pomona plan check – the manufacturer’s standard package alone is not enough. We produce the site plan, foundation drawing, and utility coordination documentation that bridges the manufacturer’s structural assumptions to your actual lot conditions. We have done this for Plant Prefab and Boxabl installations in the San Gabriel Valley and Inland Empire; the process adds roughly two to three weeks to the drawing phase because we are coordinating with the manufacturer’s engineering team in parallel. The fee for that coordination drawing package typically runs $5,500 - $9,000, written price before work starts.

Do the blueprints Ellery produces also work if I decide to use my own contractor?

The permit set belongs to you. If you want to take the approved drawings to a contractor of your choice, you can – the drawings are stamped in your project’s name. That said, the single-contract design-build model exists specifically because drawings produced without construction knowledge tend to have coordination gaps that surface during framing, not during plan check. When Ellery builds from Ellery drawings, any deviation from the approved set is covered by the 365-Day Done Right Promise. When a third-party contractor builds from our drawings, that warranty coverage does not extend to their work. Call (657) 286-7915 if you want to talk through which arrangement makes sense for your Pomona project.

Why the Drawings Matter More Than Most Homeowners Expect

Most ADU cost overruns in Pomona do not start on the job site. They start in an incomplete permit set. A missing egress note sends the application back. A foundation detail that doesn’t match the contractor’s scope creates a field change order. A Title 24 calculation based on the wrong climate zone fails inspection. Each of those events costs weeks and often thousands of dollars.

The reason Ellery treats the blueprints as the core product – not as a service to hand off cheaply before the real work begins – is that a complete, coordinated set is the only document that protects you through every stage that follows. The lender reads it. The city checks it. The inspector uses it. The tenant’s future landlord-tenant attorney can subpoena it. It is worth doing once, correctly, at a written price you agreed to before we touched a pen.

Nadia Ellery built the studio around this principle in 2015, the year California began systematically loosening ADU permitting barriers. The logic then is the same as it is now: a homeowner making a six-figure decision deserves a document, not a promise. The permit set is that document.

If you want to understand how the blueprint phase connects to the full approval and construction timeline, the Ellery ADU Studio home page gives you the complete picture of how the single-contract model works from first consultation through final inspection.

Key Takeaways

• ADU blueprints in Pomona require a full architectural and engineering set – not a sketch – to pass plan check at the City of Pomona Building and Safety Division.
• Design and blueprint fees for Pomona projects run $4,500 - $22,000 depending on unit type, with a written price before any drawing begins (Haven Standard Clause 1).
• Plan check timelines currently run four to six months total, including the first-round comment response cycle.
• Sloped lots in north Pomona, existing structural conditions, and HOA requirements are the three factors most likely to add cost and time.
• Prefab units from systems like Plant Prefab and Boxabl still require site-specific drawings for Pomona plan check; Ellery coordinates that package directly with the manufacturer.
• The 365-Day Done Right Promise covers any deviation from the permitted drawings – in writing, before the project starts – when Ellery handles both design and construction.
• A free second opinion is available on any written estimate you already have. Call (657) 286-7915.

Ready to Start Your ADU Blueprints in Pomona?

Call (657) 286-7915 to speak with someone on our team today – a live person picks up, no voicemail. Tell us your address, the unit type you have in mind, and whether you have any existing drawings or bids in hand. We will tell you what a complete permit set for your Pomona lot should include and give you a written price before any work begins. If you want to understand the full scope of the permitting and design process first, our ADU Design & Permitting in Pomona page covers every phase from site assessment through final inspection sign-off.

Written by Nadia Ellery, Owner at Ellery ADU Studio Pomona, serving Pomona.