The San Diego Cost That Out-of-Town and First-Time Developers Always Underestimate

Pro formas built on the West Coast that haven't worked San Diego before tend to land within 5% of construction cost, within a few percent on revenue, and 30–50% wrong on fee burden. The line items don't show up cleanly until building permit issuance, by which point the project's already committed. The four categories below cover most of the gap on a typical multifamily project.

Development Impact Fees (DIFs)

San Diego's DIF burden is three layers stacked, not a single per-CPA rate. The City's FY 2026 Master Fee Schedule splits it as follows:

Layer 1: Build Better San Diego — citywide. Applies to every project citywide. Rates vary by unit size and project type (single-family / multifamily / senior housing) and break into five asset categories: Park, Fire, Fire (Underserved), Library, and Mobility. For a typical 750 SF multifamily unit, the citywide DIF total runs around $22,000/unit. Smaller units pay less; larger units pay more.

Layer 2: Per-community DIF overlays. Two community programs exist:

• FBA Communities (12 newer CPAs: Black Mountain Ranch, Carmel Valley, Mira Mesa, Otay Mesa, Pacific Highlands Ranch, etc.). Each has its own per-DU rate.
• Community DIF Methodology (30+ established CPAs: Barrio Logan, Downtown, North Park, Uptown, etc.). Per-DU rate split into Transportation / Park / Library / Fire components.

Whether these rates replace the Layer 1 citywide rate or add to it is a structural question that meaningfully affects total DIF — wrong assumption produces totals that may be 2x off. The FY 2026 schedule is silent on the stacking rule; reading the rates side-by-side is suggestive (e.g., Mira Mesa's $31K/MF unit is close to the citywide total at similar unit sizes, hinting at replacement) but unverified. Verify with the City Development Services Department or the Mobility Department before relying on a number.

Layer 3: Citywide overlay fees. Apply on top of Layers 1–2:

• RTCIP (Regional Transportation Congestion Improvement Program): $3,047.57 per DU citywide.
• Otay Mesa Local Mobility DIF: additional to the citywide Mobility DIF when the parcel is in Otay Mesa — $13,916/MF unit, $15,656/SF unit.

What catches developers from out of town:

• Rates aren't uniform, but they're also not as fragmented as a per-CPA-only mental model suggests. Most of the burden lives in the citywide schedule. The community overlays are real but not all CPAs have them.
• Boundary parcels are ambiguous for Layer 2 community rates. A site straddling two CPAs may pay one rate, the other, or a blend depending on staff interpretation at submittal.
• Annual changes are normal. Build Better SD rates update each fiscal year (effective ~July 1). Community overlays update on staggered cycles tied to each CPA's PFFP amendment. Lock rates at submittal, not at acquisition.

For a 24-unit multifamily project of 750 SF average units, expect:

• Build Better SD citywide: ~$528K (24 × ~$22K)
• RTCIP: ~$73K (24 × $3,047.57)
• Plus a community overlay if applicable (could be $0 to ~$750K depending on CPA and stacking rule)
• Plus Otay Mesa Local Mobility (~$334K) if in Otay Mesa

So citywide-only floor is around $600K; the upper range with community overlay and Otay Mesa supplement can exceed $1.5M. The variance between projects is mostly driven by which CPA the parcel sits in.

Inclusionary affordable housing in-lieu fee

SDMC §142.13 requires every project of two or more units to either set aside a percentage of units as deed-restricted affordable, OR pay a per-square-foot in-lieu fee on the project's residential floor area.

The math:

• Triggered citywide at the 2-unit threshold. A duplex pays. A 200-unit project pays.
• Calculated on net usable residential floor area, not unit count. A 200-unit project of 750 SF average units owes the fee on 150,000 SF of residential floor area.
• Citywide flat rate, currently around $25/SF (verify against the current City schedule before relying on this number; the rate is CPI-adjusted annually).
• State Density Bonus, Complete Communities, and SB-1211 with affordable set-asides reduce or eliminate the in-lieu obligation by satisfying the on-site requirement structurally. Pure market-rate by-right projects pay full rate.

A market-rate by-right project at 24 units × 750 SF avg owes ~$460,000 in inclusionary in-lieu fees before doors open. That's the single largest fee line on a typical multifamily project, and it's the line that most surprises out-of-town developers.

Sewer and water capacity fees

San Diego Public Utilities charges two separate capacity fees:

• Sewer capacity — per Equivalent Dwelling Unit (EDU). Multifamily typically uses 1 EDU per unit at the Buildable San Diego default; actual EDU rates vary by bedroom count (studios closer to 0.6–0.7, three-bedrooms closer to 1.2–1.3). Plan for ~$3,000–$6,000 per unit at current rates.
• Water capacity — per meter size, not per unit. A 50-unit project typically requires a 2"–3" service meter; capacity fees scale roughly geometrically with size. Plan for ~$25,000–$80,000 for the building meter depending on size.

These are paid to the City Public Utilities Department at building permit issuance and are non-trivial. Total: another $100K–$250K on a typical mid-sized project.

The number that catches developers: water meter sizing depends on fixture-unit count, not unit count. A 24-unit project with 24 dishwashers + 24 washer/dryers + 48 bathrooms pulls more demand than the unit count alone suggests. The plumbing engineer determines actual meter size during design; until then, a unit-count heuristic is directional only.

School impact fees

California Government Code §65995 lets school districts charge per-square-foot impact fees on residential development. The rate is published annually by the State Allocation Board, currently sitting around $5/SF residential for Level I (statutory base).

San Diego's school district overlays are where this gets messy:

• Most parcels in the city sit in two districts simultaneously — one elementary district, one high-school district. Both charge.
• Rates differ by district. San Diego Unified covers most of the city. Sweetwater Union HSD covers South Bay high schools. San Ysidro Elementary, Chula Vista Elementary, and others cover South Bay elementary. A South Bay parcel pays both Sweetwater and the elementary district's rates.
• Level I, Level II, and Level III rates exist. Most projects pay Level I. Level II requires the district to make a specific mitigation finding and roughly doubles the rate. Level III applies only when state funding lapses (rare).

For a 24-unit project of 750 SF average:

• 18,000 SF residential × $5/SF Level I × 2 districts = ~$180,000 in school impact fees.
• The Level II case (with mitigation finding): ~$360,000.

This line catches developers more than any other. Most pro formas budget zero for it. It hits at building permit, in cash, non-negotiable.

Order of magnitude check

For a representative 24-unit market-rate by-right multifamily project of 750 SF average units on an inner-city parcel (no community overlay applies, not in Otay Mesa), expect:

Roughly $60,000–$100,000+ per unit in fees on a market-rate multifamily project. That's a meaningful chunk of the project budget, and pro formas that treat fees as a 5–8% reserve item typically underestimate by half. Projects in established Layer 2 community-overlay CPAs or in Otay Mesa land at the high end.

What changes the math

A few things move the burden materially:

1. Pathway selection. State Density Bonus or Complete Communities pathways with on-site affordable set-asides can drop the inclusionary line to zero. The trade-off is the deed restriction, but on a market-rate-only project that's already overbudget on fees, the SDBL pathway can pencil where the by-right pathway can't.
2. Community plan area. Whether a parcel sits in an FBA Community, a Community DIF Methodology CPA, or neither materially affects Layer 2 burden. Site selection that ignores this is leaving real money on the table — particularly for projects evaluating multiple parcels in adjacent CPAs.
3. School district overlay. South Bay parcels paying two school districts pay roughly twice what a parcel inside SDUSD-only territory pays. Worth checking before acquisition.
4. Project size. Most fees scale linearly with units or floor area. A 12-unit project pays half what a 24-unit project pays. Below the inclusionary 2-unit threshold (single-family, ADUs only), the inclusionary line drops out entirely.

How to verify

Fee estimates in this calculator should be treated as directional, not authoritative. Before acquisition or financing decisions, request the current published fee schedule from:

• City of San Diego Development Services Department — for the Master Fee Schedule (DIFs, building permit, plan check, stormwater).
• City of San Diego Public Utilities Department — for sewer and water capacity fees.
• The relevant school district(s) — for the current Level I/II rates.
• The Inclusionary Affordable Housing Regulations under the Housing Commission — for the current per-square-foot in-lieu rate.

The numbers move quarterly to annually. The variance between published schedule date and project's permit-issuance date is where pro forma surprises live.