CheckMyDesignerArchitect vs. structural engineer: who do you need for your home remodel?
Last checked Nov 6, 2026
The short answer
- The architect designs the layout, the look and code compliance. The structural engineer designs what holds the building up.
- A structural-only job, like a foundation repair or a seismic retrofit, can go straight to an engineer.
- Layout changes, additions and ADUs usually need both, on the same permit set.
- For those, hire the architect or designer first, then the engineer.
An architect designs how your home looks, flows, and complies with zoning, planning, fire, and building codes, while a structural engineer calculates the gravity and earthquake loads and designs the beams, posts, shear walls, and foundations that hold the building up (California Business and Professions Code Section 5500.1, Section 6731, and Section 6735). You need only a structural engineer when your project is strictly structural, such as removing a single load-bearing wall or completing a seismic retrofit; you need an architect (or an exempt building designer under B&P Code §5537) plus a structural engineer when you are changing room layouts, expanding the building, or adding an ADU in San Francisco.
On most major San Francisco remodels, it isn’t an either/or choice. The architect and structural engineer produce separate sheets of the same permit drawing set submitted to the San Francisco Department of Building Inspection (DBI).
Architect vs. structural engineer: side-by-side comparison
California licenses architects and engineers under two separate practice acts and two separate state boards:
| Comparison point | Licensed Architect | Structural or Civil Engineer |
|---|---|---|
| California licensing board | California Architects Board (CAB) | Board for Professional Engineers, Land Surveyors, and Geologists (BPELSG) |
| License prefix and protected title | “C” followed by numbers (such as C-34567). Protected title: “architect” and “architectural designer.” | “C” for Civil Engineer and “S” for Structural Engineer. Protected title: “professional engineer,” “civil engineer,” “structural engineer.” |
| Primary job on a home remodel | Space planning, floor plans, elevations, window/door layouts, San Francisco Planning Code and historic review, building code egress, accessibility, and finish coordination. | Gravity and seismic load calculations, foundation and retaining wall design, wood and steel framing sizes, shear walls, moment frames, and structural connection details. |
| Sheets they stamp in a DBI permit set | Architectural sheets (“A-sheets”: A0, A1, A2, etc.), signed and stamped. | Structural sheets (“S-sheets”: S1, S2, S3, etc.) and the structural calculation package, signed and stamped. |
| Written contract required by law? | Yes, before work begins. | Yes, before work begins. |
| Public license and discipline lookup | Architect license lookup / CAB Search | Engineer license lookup / BPELSG Lookup |
Sources: B&P §5536 · B&P §6735 · §6736 · B&P §5536.1 · B&P §5536.22 · B&P §6749
Note that both California architects and California civil engineers have license numbers that start with the letter “C.” Always check whether the license is issued by CAB (Architect) or BPELSG (Civil Engineer) on DCA License Search.
Who you need by project type in San Francisco
Use this table to see whether your San Francisco project calls for an architect (or exempt building designer), a structural engineer, or both:
| San Francisco project | Architect or exempt designer? | Structural engineer? | Who to hire first |
|---|---|---|---|
| Removing one interior load-bearing wall (no room additions or window changes) | Not required unless you want kitchen/living layout options | Yes, required to stamp beam, post, and footing calculations | Structural engineer |
| Soft-story seismic retrofit, foundation bolting, or underpinning | No | Yes | Structural engineer |
| Interior bathroom or kitchen layout remodel (moving non-bearing partitions only) | Yes, architect or exempt building designer | No, if no bearing walls, joists, or lateral shear walls are altered | Architect or building designer |
| Full kitchen and open-plan remodel that removes bearing walls or cuts wide exterior doors | Yes, for layout, cabinetry, lighting, and code drawings | Yes, for gravity beam and lateral shear-wall/moment-frame calculations | Architect or designer first; they bring in the structural engineer |
| Garage conversion ADU or basement unit legalization | Yes, for Planning Code, fire separation, egress, and unit layout | Yes, whenever foundation excavation, seismic framing, or multi-story load paths are affected | Architect first |
| Horizontal rear addition, vertical story addition, or hillside remodel | Yes, for Planning notification, design review, and architectural plans | Yes, for foundation and lateral seismic engineering | Architect first |
Sources: B&P §6737.1(b) · SF.gov · B&P §5537 · SF.gov · SF.gov · SFBC §106A.3.1.3 · SF.gov
Remember that for wood-frame single-family homes and 1-to-4 unit buildings up to two stories plus a basement, California B&P Code §5537 and B&P Code §6737.1 allow an unlicensed building designer to prepare the architectural floor plans and pair with a licensed structural engineer who stamps the non-conventional structural sheets. See architect vs. building designer in California for how that pairing works.
Who to hire first (and how they work together)
If your project needs both architectural layout design and structural engineering, hire the architect (or building designer) first.
A structural engineer cannot size beams, posts, or shear walls until someone has decided where the walls, windows, stairs, and rooms will go. In a standard San Francisco remodel, the collaboration follows four steps:
- Schematic design: Your architect or building designer measures the house and draws floor plans, elevations, and sections that meet your goals and the San Francisco Planning Code.
- Structural engineering coordination: The architect sends the CAD or BIM backgrounds to the structural engineer. The engineer calculates the gravity and seismic loads, places shear walls, beams, and footings to fit the layout, and stamps the S-sheets and calculation book (B&P Code §6735).
- Permit submittal and plan check: Both the architectural A-sheets and structural S-sheets are combined into a single submittal for DBI (SFBC Section 106A.3.2). During plan check, the architect answers Planning, building code, and fire comments, while the engineer answers structural plan-check comments (SF.gov building permit review processes).
- Construction administration and observation: Once work starts, the architect checks that rooms, windows, and finishes match the design, while the structural engineer performs structural observation, when required, of open foundations, steel welds, and framing connections before the walls are closed.
Some homeowners contract directly with the structural engineer (often recommended by their architect), while others have the architect include the structural engineer as a subconsultant under one contract. Either way, ask for the structural engineer’s name and license number up front so you can check their record too.
Not sure you need an architect at all? See when you need an architect. For the engineer’s side of the job, see what a structural engineer does on a home remodel.
Can an architect do structural engineering, or can an engineer draw architectural plans?
Under California law, the two licenses overlap on paper more than they do in everyday San Francisco practice:
- Can a licensed architect stamp structural calculations? Under B&P Code §6737, a California-licensed architect is exempt from engineer registration insofar as they practice architecture. The California Architects Board’s Building Official Information Guide reads this to mean an architect may design any building type and all its parts. The one exception it names is the structural design of a hospital. An architect still may not call themselves a “structural engineer” without that license (B&P Code §6736). In practice, however, most San Francisco residential architects bring in a dedicated civil or structural engineer for seismic moment frames, underpinning, and multi-story load calculations.
- Can a licensed engineer draw architectural permit plans? Under B&P Code §5537.4 (professional engineers) and B&P Code §5537.1 (structural engineers), a California-registered engineer is exempt from the Architects Practice Act insofar as they practice the profession for which they are registered, as long as they don’t use the title “architect.” On structural-led projects like soft-story retrofits or bearing-wall removals, engineers routinely produce the entire permit drawing set. On aesthetic or layout-heavy remodels, most engineers prefer to work alongside an architect or designer.
To compare engineering fee structures before you hire, see how much a structural engineer costs and questions to ask an architect before you sign.
Common questions
- Do I need both an architect and a structural engineer for a remodel?
You need both when your remodel changes both the layout of the house and its structural framing, such as an open-plan kitchen remodel that removes a bearing wall, a garage ADU conversion, or a horizontal or vertical addition (B&P Code §5537(b), SFBC Section 106A.3.2). If you are only removing one bearing wall or doing a seismic retrofit without changing room layouts, you usually only need a structural engineer.
- Should I hire an architect or a structural engineer first?
If your project involves layout changes, new windows, an addition, or an ADU, hire the architect (or building designer) first so they can establish the floor plan and Planning Code envelope before the engineer sizes the framing. If your project is strictly structural, such as foundation repair, soft-story retrofitting, or sizing a single replacement beam, hire the structural engineer directly.
- Can a structural engineer stamp architectural plans in California?
Under B&P Code §5537.4 and B&P Code §6735, a California-licensed civil or structural engineer may prepare, sign, and stamp building plans within the scope of their engineering registration, provided they do not call themselves an “architect” (B&P Code §5536).
- Why do both California architects and civil engineers have “C” license numbers?
The California Architects Board prefixes architect licenses with “C,” while BPELSG also uses “C” for Civil Engineers (and “S” for Structural Engineers). When you check a “C” license number, verify the issuing board so you know whether the person is a licensed architect or a licensed civil engineer.
Sources
- California Business and Professions Code §5500.1, §5536, §5536.1, §5536.22, §5537, §5537.1 & §5537.4 (Architects Practice Act), California Legislative Information. Read Nov 6, 2026.
- California Business and Professions Code §6731, §6735, §6736, §6737, §6737.1 & §6749 (Professional Engineers Act), California Legislative Information. Read Nov 6, 2026.
- Building Official Information Guide (2021), California Architects Board. Read Nov 6, 2026.
- San Francisco Building Code Section 106A.3.2 (Submittal Documents), American Legal Publishing / City and County of San Francisco. Read Nov 6, 2026.
- Learn about our building permit review processes, City and County of San Francisco (SF.gov). Read Nov 6, 2026.
- California Architects Board License Search, California Department of Consumer Affairs (CAB). Read Nov 6, 2026.
- BPELSG License Lookup (Board for Professional Engineers, Land Surveyors, and Geologists), California Department of Consumer Affairs (BPELSG). Read Nov 6, 2026.
This is general information, not legal advice.
More guides
- When do you need a building permit in San Francisco?Which home projects need a San Francisco building permit, the short list of jobs that don’t, and how to check before you start.
- Do you need a permit to remodel a bathroom or kitchen in San Francisco?Why San Francisco requires a permit even for like-for-like kitchen and bathroom remodels, and when you also need drawings.
- What happens if you build or remodel without a permit in San Francisco?How San Francisco finds work done without a permit, what it costs when it does, and how to make the work legal.
- Selling or buying a house with unpermitted work in CaliforniaWhat California sellers must disclose, what a San Francisco 3R Report shows, and your options before closing.
- Questions to ask an architect before you signWhat to ask before you sign a design contract, why each answer matters, and how to check it.
- Architect vs draftsman vs building designer in CaliforniaWho may draw your plans in California, which homes are exempt, and who must stamp the rest.