Timber Carports
PE-stamped structural design for wood-framed carports: post-and-beam framing, NDS-compliant connections, wind and seismic calcs, foundation design.
View serviceService
ADUs & Retrofit Structural Engineering.
ADUs and retrofits live at the intersection of new construction and existing-building engineering. We design detached and attached ADUs, garage conversions, soft-story retrofits, foundation bolting, and cripple-wall bracing — all with the calc package and stamped drawings the jurisdiction expects.
What's included
Engineering scope for ADUs and retrofits
- New ADU design: gravity, lateral, and foundations as a complete structural system
- Garage and basement conversions: lateral upgrades when removing or modifying shear walls
- Soft-story retrofits to ASCE 41 / city ordinance (LA, SF, Oakland, Berkeley, others)
- Foundation retrofits: sill-plate anchorage, cripple-wall plywood bracing, hold-downs
- Verification of existing framing and foundations against the new load demand
- Coordination with Title 24 / energy and the architect of record
Deliverables
What you receive
- Stamped structural sheets for the ADU or retrofit scope
- Signed and sealed calculation package
- Existing-conditions assessment when the scope modifies the existing structure
- Hardware and anchor schedule (Simpson / MiTek, Hilti / Simpson adhesive anchors)
- Plan-check response support through permit approval
Applicable codes
We design to
- California Building Code (CBC) and California Residential Code (CRC) for CA projects
- IBC / IRC and local amendments for non-CA jurisdictions
- ASCE 41 — Seismic Evaluation and Retrofit of Existing Buildings
- ASCE 7-16 / 7-22 for loads on new construction within the retrofit
- Local mandatory-retrofit ordinances (LA Ordinance 183893, SF Soft Story, others)
PE-stampedPermit-readyU.S. jurisdictions
Who it's for
Built for the teams that ship the project
- ADU builders and design-build firms permitting detached and attached units
- Architects converting garages, basements, or accessory spaces into livable units
- Property owners required to complete a mandatory soft-story or foundation retrofit
- Real-estate investors preparing a multifamily building for a value-add renovation
FAQ
ADUs & Retrofits — questions, answered
Do you work with state-approved ADU plan sets, or only custom designs?
Both. We engineer custom ADUs from architectural plans, and we also adapt pre-approved or stock plans to a specific lot's soil, seismic, and zoning conditions.
Can you perform soft-story retrofits under city mandatory ordinances?
Yes. We design to the specific ordinance (LA, SF, Oakland, Berkeley, Santa Monica, others) and produce the screening forms and structural drawings the program requires.
Garage conversion — when does removing the garage door become a structural problem?
Almost always. The garage-door opening is usually the weakest lateral element on the wall; removing it without engineering it back in fails plan-check. We design a moment frame, portal frame, or shear wall to replace what's lost.
Do you coordinate with the geotechnical engineer on foundation retrofits?
Yes. When the retrofit touches the foundation, we incorporate the geotech recommendations directly into the design — bearing values, anchor embedment, and any required underpinning.
Related services
Other structural engineering services
Steel Carports
Structural engineering for steel-framed carports and canopies: HSS and W-section design to AISC 360, moment-frame lateral systems, and stamped drawings.
View serviceAttached Structures
Structural engineering for patio covers, pergolas, sunrooms, and home additions attached to an existing house: ledger design, load path verification, stamped plans.
View serviceFrom the blog
Recent insights related to this service
Ready to engineer your ADUs and retrofits? Let's scope it.
Send your drawings, sketches, or site address — we'll come back with a fixed proposal for the structural scope.