Additions & Remodeling — San Diego
What Does San Diego Require for a Single-Story Addition or Remodel in 2026?
Before a single wall comes down, the City of San Diego applies a specific set of energy, structural and site rules to single-story additions and remodels — separate from the general permit process. Here is exactly what Information Bulletin 140 requires, and where an older home can run into an extra review step.
Key takeaways
- Any single-story addition or remodel to a house or duplex in San Diego falls under Information Bulletin 140, which sets prescriptive requirements separate from the general building code.
- Projects that disturb 1,000 square feet or more of ground generally need a Minor Water Pollution Control Plan; disturbance of 1 acre or more requires the full version.
- The bulletin’s energy table sets different ceiling, wall and floor insulation minimums depending on whether the home sits in Climate Zone 7 or Climate Zone 10.
- Homes 45 years or older require a historical resources review before a permit is issued for exterior work — common in neighborhoods with an older housing stock, such as North Park.
- The bulletin’s structural minimums apply whether you build to the prescriptive tables or bring in an engineer for custom calculations.
- None of this sets your permit fee — that is a separate city fee schedule, covered in our dedicated guide.
In this guide
What Information Bulletin 140 Covers
Information Bulletin 140, “Residential Addition/Remodel,” is the City of San Diego’s guidance document for permitting additions and remodels to single-family dwellings and duplexes that do not exceed one story in height above grade or above a crawl space. It was last updated in April 2026, so it reflects the city’s current requirements.
It does not replace the question of whether you need a permit at all — we cover that separately for a home addition and a whole-home remodel. Instead, it sets the technical minimums your plans have to meet once you are ready to submit: stormwater controls, energy compliance, and structural specifications.
For a premium single-story addition or a whole-home remodel, these are not details to work out after design begins — they shape which rooms can go where, how much glazing an ocean-facing wall can carry, and whether a project needs an engineer before the design is finished. Treating Information Bulletin 140 as a design input, not a plan-check afterthought, is what keeps a project moving on schedule.
Site & Stormwater Thresholds Before You Dig
How much paperwork your grading and site work require depends on how much ground your project disturbs. Information Bulletin 140 sets three tiers:
| Disturbed ground area | What San Diego requires |
|---|---|
| Under 1,000 sq ft | General Best Management Practice (BMP) notes on the submitted plans |
| 1,000–4,999 sq ft, elevation differential under 5 ft | A Minor Water Pollution Control Plan (Form DS-570) may be used |
| 1 acre or more | A full Water Pollution Control Plan is required |
Most single-story additions and remodels fall into the first two tiers. The acre-scale tier mainly matters for larger lots carrying out extensive grading alongside an addition, which is more common on hillside or rural-zoned parcels.
Energy Code Minimums for Your Addition
Information Bulletin 140 includes a prescriptive energy table — Table 9 in the bulletin — covering San Diego’s two climate zones, Zone 7 (closer to the coast) and Zone 10 (further inland). It sets minimum insulation and glazing performance for additions and remodels that use the prescriptive path rather than full energy modeling.
| Building element | Minimum standard |
|---|---|
| Ceiling insulation | R-30 to R-38 |
| Wall insulation | R-13 cavity plus R-8 continuous |
| Floor insulation | R-19 |
| Fenestration (windows/doors) area | Max 20% of conditioned floor area; U-factor ≤ 0.30 |
| West-facing glazing | Max 5% of floor area; SHGC ≤ 0.23 |
These are the prescriptive minimums; they sit apart from the broader question of whether California’s newest energy standards apply to your project, which we cover in our guide to San Diego’s 2026 energy code. The California Energy Commission confirms the 2025 Building Energy Efficiency Standards took effect statewide on January 1, 2026.
Structural Minimums You’re Building To
Alongside energy performance, Information Bulletin 140 sets prescriptive structural specifications for single-story work. These are the baseline numbers a standard addition is built to meet, whether or not your project also needs engineer-stamped calculations for anything beyond the prescriptive path.
| Element | Prescriptive minimum |
|---|---|
| Roof live load | 20 psf |
| Floor live load | 40 psf |
| Concrete strength | 2,500 psi minimum |
| Slab thickness | 3.5 inches minimum |
| Roof covering | Class A minimum |
The 45-Year Historical Review Trigger
One requirement in Information Bulletin 140 surprises more homeowners than any other: any building 45 years old or older that is undergoing exterior work requires a historical resources review before the city issues a permit.
This isn’t limited to homes with a known historic designation — the 45-year threshold applies broadly, and the review simply confirms whether a given property has historic significance before exterior changes proceed. It comes up often in neighborhoods built out with early- and mid-20th-century housing, such as North Park, where a large share of the housing stock is old enough to qualify.
Historical review runs on its own timeline, separate from standard plan check, and it can add real time to a project before construction drawings even get in front of a plan checker. If your home is in this age range and your scope includes exterior work, confirm the review requirement and its expected timeline with San Diego Development Services before you commit to a start date.
Prescriptive Tables vs. Hiring a Design Professional
The prescriptive tables in Information Bulletin 140 exist so that a straightforward, code-compliant single-story addition can be designed and permitted without a full engineering analysis of every component. They work when a project’s spans, loads and layout fall within the table’s assumptions.
Once a project departs from those assumptions — a larger-than-typical roof span, an unusual load path, a wall removal that affects structural framing, or a lot with site conditions the tables don’t anticipate — the prescriptive path no longer applies, and the plans need project-specific calculations from a licensed architect or civil/structural engineer instead. Knowing which category a given addition falls into, before plans are drawn, is exactly what a design and engineering team is for.
- Standard-span, single-story additions with typical room layouts usually qualify for the prescriptive path.
- Vaulted ceilings, large openings, unusual roof geometry or wall removals usually require engineered calculations.
- A soils report may also be required depending on site conditions — we cover that separately for home additions in San Diego.
- Coastal-zone and hillside lots often carry additional overlay requirements on top of Information Bulletin 140, which is another reason to confirm scope with a design professional before finalizing a floor plan.
This is also where a design-build structure pays off directly: when design, engineering and permitting sit under one roof, the person drawing your floor plan already knows which rooms will force an engineered calculation, rather than finding out after the plans are submitted.
Where This Fits in Your Overall Permit Process
Information Bulletin 140 governs the technical content of your plans. It sits alongside, not instead of, the rest of San Diego’s permit process: confirming whether you need a permit at all, submitting through the city’s electronic plan review portal, paying plan check and inspection fees, and scheduling inspections through construction. We walk through that fuller sequence, including typical plan-check cycles, in our remodel timeline guide, and the separate fee amounts in our building permit fees guide.
If your project is a detached accessory dwelling unit rather than an addition to the existing house, Information Bulletin 140 is not the controlling document — ADUs follow their own size, setback and parking rules, which we cover in our ADU rules guide.
Does Information Bulletin 140 apply to two-story additions?
No. The bulletin is scoped to additions and remodels that do not exceed one story in height above grade or above a crawl space. A two-story addition is reviewed under the full building code process rather than this bulletin’s prescriptive tables.
What triggers a historical review on my remodel?
Per Information Bulletin 140, any building 45 years old or older undergoing exterior work requires a historical resources review before a permit is issued, regardless of whether the home has a known historic designation.
Do I need a full Water Pollution Control Plan for a small room addition?
Usually not. Under the bulletin’s thresholds, disturbing less than 1,000 square feet of ground only requires general BMP notes on your plans, and 1,000–4,999 square feet (with an elevation differential under 5 feet) can typically use the Minor Water Pollution Control Plan instead of the full version.
What’s the minimum insulation required for a single-story addition?
The bulletin’s prescriptive energy table sets ceiling insulation between R-30 and R-38, wall insulation at R-13 cavity plus R-8 continuous, and floor insulation at R-19, with additional limits on window and door area and performance.
Does Information Bulletin 140 set my permit fee?
No. Plan check and inspection fees are set by a separate city fee schedule. Our San Diego building permit fees guide covers those amounts.
Can I design to the prescriptive tables, or do I need an engineer?
If your addition’s spans, loads and layout fall within the bulletin’s assumptions, the prescriptive tables can carry the design without additional engineering. Once a project includes larger spans, unusual loads or structural wall changes, it needs project-specific calculations from a licensed architect or engineer instead.
Does this bulletin apply to ADUs?
Information Bulletin 140 covers additions and remodels to existing single dwellings and duplexes. A detached accessory dwelling unit is reviewed under San Diego’s separate ADU requirements rather than this bulletin.
Planning a single-story addition or remodel in San Diego?
Eco Home Builders handles design, engineering, permitting and construction for additions and whole-home remodels across San Diego and Orange County. Tell us about your home and we’ll walk you through what your specific project needs.
Sources
- City of San Diego, Information Bulletin 140, “Residential Addition/Remodel,” April 2026
- City of San Diego, Information Bulletin 501, “Fee Schedule for Construction Permits-Structures,” August 2026
- California Energy Commission, 2025 Building Energy Efficiency Standards
- City of San Diego Development Services, Permits
Code requirements above are summarized from the cited City of San Diego and California Energy Commission publications and may be updated by those agencies; confirm current requirements with San Diego Development Services before relying on them for a specific project. This article contains no Eco Home Builders pricing — any figures are code minimums, not project costs or quotes.
