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CADTRI

Permitting

Home Addition Packages

Complete permit-ready drawing packages for residential additions: room additions, second stories, and covered expansions.

Scope Coverage

Eight addition types. One complete permit package.

Single Room AdditionSecond Story AdditionMaster Suite AdditionCovered Patio / Outdoor RoomSunroom or Enclosed PorchAttached Garage AdditionIn-Law Suite AdditionKitchen or Dining Expansion

8+

Addition Types

7–12 Days

Turnaround

Target

First-Pass Approval

All US

Jurisdictions

The Process

From site to submission.

  1. Existing Conditions Documentation

    We establish the existing structure on record (floor plan, elevations, and site conditions) as the baseline from which the addition is drawn. Accuracy here prevents corrections during plan check.

  2. Addition Design Drafting

    The proposed addition is drawn in full, coordinated against the existing structure: new floor plans, exterior elevations, building sections, and all required detail drawings.

  3. Code and Zoning Compliance

    The addition is reviewed against setback requirements, lot coverage limits, FAR, height restrictions, and all applicable building code requirements including egress, structural, and energy compliance.

  4. Permit Set Assembly

    All sheets are compiled into a jurisdiction-specific submission package, formatted to the building department's requirements, with a complete title sheet, code summary, and sheet index.

Deliverables

What every package includes.

01

Existing Conditions Floor Plan

Measured plan of the existing structure showing all dimensions, wall locations, openings, and conditions relevant to the proposed addition scope.

02

Proposed Addition Floor Plan

Complete dimensioned plan of the addition with all new construction shown in context with the existing structure.

03

Exterior Elevations

All affected building elevations showing the addition in context with the existing structure, with heights, materials, and openings called out.

04

Building Section

Cross-section through the addition showing structural assembly, ceiling heights, insulation locations, and floor-to-floor dimensions.

05

Site Plan

Site plan showing the addition footprint against property lines, with all required setback dimensions and updated lot coverage calculation.

06

Title Sheet and Code Summary

Project identification, scope description, applicable codes, and all regulatory summary information required by the jurisdiction.

Why Additions Fail Plan Check

Addition permits are rejected more often than new construction permits because the existing structure introduces variables that make compliance harder to demonstrate. A package built specifically for the addition type, not a generic template, passes plan check faster.

Common rejection reasons

  • Setback violations not caught before submission
  • Existing conditions incorrectly documented
  • Missing coordination between existing and new structure
  • Energy compliance omitted for conditioned additions
  • Jurisdiction-specific sheet requirements not met

Common Questions

Frequently asked.

Still have questions? Contact us and we will answer them directly before you submit an inquiry.

Do you handle additions that require structural engineering?
Yes. We coordinate with the structural engineer of record. Our structural coordination service handles the integration of structural drawings into the permit set. We manage the coordination so you have one submission-ready package.
What if the existing structure isn't in the city's records?
We work from your provided measurements, site photos, or an existing conditions survey. We document on the title sheet that existing conditions are based on field measurement. Most jurisdictions accept this for additions under a certain size threshold.
Can you match the existing architecture?
Yes. We draw the addition to match or complement the existing structure's architectural style, materials, and proportions as documented in your provided reference.
Do you cover additions in California?
Yes. California additions require Title 24 energy compliance documentation, which is included in our California permit packages.

Designed For

Who this serves.

  • Homeowners

    Adding living space to an existing home and need permit documentation to proceed with construction.

  • General Contractors

    Who need a complete permit set for a client's addition project before pulling the building permit.

  • Design-Build Firms

    Who need a production drafting partner to deliver permit sets on client addition projects.

  • Real Estate Investors

    Adding square footage to increase property value and need a code-compliant permit set for the work.

Ready to permit your addition?

Share your project scope, jurisdiction, and any existing drawings. We confirm the package contents and timeline before starting.