ADU & Garage Conversion Title 24 Reports

Start with the dwelling and its existing condition

This service is for owners, architects and builders preparing energy documentation for a detached ADU, an attached addition, a garage conversion or a mixed project involving the original home. Title 24 Lab is a provisional brand for design-document preparation and coordination. We begin with what exists, what becomes conditioned and which systems change—not an assumption that every project called an ADU needs the same model.

Coordinating a builder package? Use the ADU builder and garage-conversion GC intake pathway to align unit boundaries, schedules and published residential pricing before uploading plans.

Current planning uses the 2025 California Energy Code for permit applications on or after January 1, 2026; confirm the AHJ-recorded date and the treatment of changes to an earlier application. For the applicant’s classification decision tree, worked example and JADU definition, read the ADU and garage-conversion guide. It complements this service scope rather than replacing project-specific review.

Five-stage workflow: from intake to coordinated permit support

Each stage has a decision owner and a handoff. Preliminary assumptions stay visible until the client and responsible designers confirm them. A saved quote request is not payment, production acceptance or a permit approval.

1. 1. Intake: establish the existing and proposed scope

   The client or architect supplies existing/proposed plans, conditioned areas, dwelling count, application record and available prior reports. We identify missing information and separate new detached construction, newly conditioned space and alterations. The AHJ resolves uncertain permit history or application-date treatment; we do not invent a prior conditioned use from a photograph or a finished wall.

2. 2. Path selection and preliminary modeling

   We assess the applicable prescriptive or performance documentation approach using the project’s classification and edition. The architect and systems designer confirm assemblies, equipment and dwelling boundaries. If options remain open, a preliminary study can compare supported choices. It is not a final CF1R or an assurance that any later product substitution will comply. See energy-modeling scope for that distinction.

3. 3. Prepare the CF1R and supporting design package

   Using the coordinated inputs, we prepare the applicable design compliance output, including CF1R where the single-family family applies, and identify measures that must be shown on the plans. Responsible design declarations and any required registered-copy process are coordinated with the appropriate parties. Preparation does not claim ECC-Provider operation, installer certification or a completed field test.

4. 4. Client and designer review

   The client and responsible designers compare the package with the named drawing revision: window sizes and performance, assemblies, HVAC, ventilation and domestic hot water. Open items are resolved before the output is treated as final. We record changed assumptions so an early option run does not accidentally become the controlling permit package while the plans continue to change.

5. 5. Permit and plan-check documentation support

   The applicant submits the coordinated package through the AHJ’s process. If comments arrive, supply the complete letter and actual reviewed documents so the response can be scoped. Installers and qualified ECC-Raters handle their applicable construction-stage records separately. We support documentation responses, not city staffing, permit issuance or an unconditional review deadline.

What to prepare before requesting a quote

Send readable PDF plans, with supporting DWG or ZIP files where useful. Separate existing and proposed drawings and identify which sheets supersede older ones. The energy-consultant intake checklist explains file naming, missing schedules and practical submission preparation.

The most useful packet lets us identify a boundary, a design basis and the unresolved decisions. If a value is unknown, label it as preliminary instead of substituting another project’s number. Prior approved documents can be evidence; they are not automatic permission to reuse their assumptions for changed work.

• +Site plan and orientation; dimensioned floor plans, elevations and sections; existing/proposed conditioned areas and the number of dwellings in the requested documentation scope.
• +Former use and conditioning history for each converted area, with available permit records; show shared walls, floors and ceilings and any new building area.
• +Window/door schedule with sizes, U-factor and SHGC; assembly descriptions and insulation intentions for retained, replaced and new components.
• +HVAC, ventilation and domestic hot-water schedules from the responsible designer; distinguish dedicated systems, proposed extensions and affected main-house equipment.
• +Application record, confirmed edition if available, prior energy documents, proposed PV/battery information, complete reviewer comments and a clear revision summary.

Garage-conversion issues that change the documentation path

Existing footprint is not existing conditioned area. The CEC treats an unconditioned garage becoming conditioned space as an addition under Section 150.2(a). A conversion within already conditioned space is an alteration under Section 150.2(b). A detached garage conversion is not automatically the same as constructing a new detached building. Establish that history before choosing the model.

Retained structure still needs a supported envelope description. Identify the actual wall, roof, floor and slab conditions and which components change. Existing finishes do not prove an insulation value. Clearly distinguish retained windows from replacements, and coordinate new opening sizes, orientation, U-factor and SHGC with the drawings rather than relying on a generic “dual-pane” note.

An HVAC extension is a design question, not a shortcut in the model. The CEC’s ADU FAQs specifically reject an existing dwelling’s ducted forced-air system serving a separate ADU in the described scenario. Have the mechanical designer resolve systems and ventilation; a shared utility meter does not establish acceptable shared air distribution. Report preparation is not mechanical design.

For a JADU, the Energy Code definition and actual work matter. The CEC describes an internal single-family unit no larger than 500 square feet, with the specified kitchen and access arrangement; the label alone does not settle energy or planning eligibility. Consult the CEC 2025 ADU FAQs and supply the real existing/proposed scope.

Prescriptive, performance and PV questions

A newly constructed detached ADU follows newly constructed single-family requirements, including mandatory measures and the selected prescriptive or performance pathway. An attached addition or conversion follows its applicable Section 150.2 scope. Performance modeling can evaluate eligible design options; it cannot trade away mandatory measures or turn unsupported existing conditions into verified inputs.

The CEC FAQs distinguish the prescriptive PV requirement for newly constructed detached ADUs, subject to applicable exceptions, from attached ADUs treated as additions. They also explain new modules added to existing systems; existing PV alone is not an automatic exemption. We identify documentation questions and coordinate supplied design information, not design the PV installation or promise an exemption. Use the CEC ADU resource hub for the edition-specific materials.

What the report package delivers—and what it does not

The agreed design package ties the applicable compliance documents to a named plan revision, records the input basis and identifies measures for drawing coordination. Where required, clarify registration status and responsible declarations before treating a copy as permit-ready. The CF1R/CF2R/CF3R service explains the separate design, installation and verification handoffs.

The client/architect owns the project scope, coordinated drawings and confirmed selections. The energy consultant prepares the design compliance documentation from that evidence. Installing contractors certify applicable installed work, and a qualified ECC-Rater performs required verification. HERS is legacy wording on older-cycle records, not the default current service label. No field-testing credential or registry operation is claimed here.

Field testing, acceptance testing, registry fees, CALGreen and AHJ permit fees are separate from the energy report. Also excluded are planning eligibility determinations, structural and mechanical design, permit filing promises and approval guarantees. If work is concealed before a required observation, consult the qualified verifier and AHJ; do not assume a design report can replace missing evidence.

Residential pricing—not a separate ADU price menu

ADU report requests use the existing residential schedule, based on conditioned area and the dwelling units in the requested documentation scope: up to 2,000 sq ft $149; 2,001–4,000 $199; 4,001–6,000 $279; above 6,000 $279 plus $50 per additional started 1,000 sq ft. Additional dwelling units beyond the first are $75 each. Confirm scope rather than automatically counting every existing dwelling on the parcel. See published pricing and exclusions.

Our modeling/report-error plan-check corrections are Free; architectural/design revisions are $75 flat; a full remodeled model or major redesign needs a Custom quote. Residential rush is +$99 for next-business-day production after complete inputs—not unconditional delivery or permit approval. Get a Quote and upload plans to confirm the request before production.

Keep the permit package and later changes consistent

When a reviewer asks for an energy correction, send the entire comment and the reviewed plan/report revision. Identify whether a specification was omitted, a modeled value was wrong, or the client changed the design. The plan-check correction service explains that decision and the three existing revision tiers.

Use the code-cycle transition guide if the application date is uncertain. Educational information is not legal advice; the AHJ determines permit requirements and local amendments. No neighborhood ordinance, parcel climate zone, city review duration or approval outcome is invented for this service.

Typical scope

• +Review of existing use, conditioning history and proposed dwelling boundaries.
• +Classification and documentation-path coordination using the applicable CEC ADU and addition guidance.
• +Modeling or prescriptive documentation for the selected approach.
• +Coordination of energy measures with the supplied architectural and systems information.

Documentation deliverables

Typical report-preparation outputs to confirm in the project scope; not a promise of field services or permit approval.

• +A documented scope/boundary explanation distinguishing conversion, new area and changes to the main house.
• +Applicable design compliance documents, with the correct form family confirmed for the building.
• +An assumptions/decisions record and energy measures to coordinate on drawings.
• +A separate handoff for installer documentation and required ECC verification; no test result is implied.

Not included / not implied

• -Permit approval is decided by the building department; documentation does not guarantee approval.
• -Construction-stage installation certificates and ECC verification are separate responsibilities; field testing and installer certification are not included in report preparation.
• -CALGreen (Title 24, Part 11) documentation, permit processing and acceptance testing are separate scopes, not implied by a Part 6 energy report.
• -Structural, mechanical design or legal advice.
• -ADU zoning eligibility, structural design, mechanical system design or a universal solar exemption.

Questions