How Portland's 2025 Building Code Changes Affect Your Paving Project

Portland's 2025 Building Code: What Paving Contractors and Property Owners Must Know

Portland's Bureau of Development Services (BDS) rolled out updated building codes in 2025 that directly impact how paving projects are planned, permitted, and constructed across the city. Whether you are repaving a residential driveway in Southeast Portland or building a new commercial parking lot in the Central Eastside Industrial District, these changes affect your timeline, budget, and design requirements.

Cojo works throughout the Portland metro area and stays current on municipal code changes so our clients do not get blindsided by requirements mid-project. Here is what you need to know about the 2025 updates and how they affect paving in Portland.

Stormwater Management: The Biggest Change

Portland has long been a leader in stormwater regulation, but the 2025 code expanded requirements that catch more paving projects in the net.

The 500-Square-Foot Threshold

Any new impervious surface exceeding 500 square feet triggers onsite stormwater management. This has been in place for years, but the 2025 code clarified two important points:

• Redevelopment trigger: Projects that disturb more than 50% of existing impervious area now require stormwater upgrades, even if total impervious area stays the same. This means a parking lot overlay that includes full-depth repairs on more than half the lot may trigger stormwater compliance.
• Cumulative calculation: Multiple small projects on the same tax lot within a 5-year period are now aggregated. A property owner who paves a 300-square-foot loading area one year and a 250-square-foot walkway the next year crosses the threshold.

What This Means for Your Project

If your project triggers stormwater requirements, you will need one or more of the following:

• Infiltration planters along the perimeter of the paved area
• Bioswales to capture and filter runoff
• Permeable pavement sections (porous asphalt or permeable pavers) that allow water to infiltrate the subgrade
• Underground detention systems in areas where surface facilities are not feasible

These features add cost — typically $3 to $8 per square foot of managed area — but they are not optional. Portland's Bureau of Environmental Services (BES) reviews stormwater plans and will not issue occupancy or completion approvals without compliance.

Cojo designs paving projects with stormwater requirements in mind from the start. Retrofitting stormwater features into a project that was not designed for them is far more expensive than incorporating them during initial planning. Contact us early in your project to discuss stormwater-compliant paving options.

ADA Parking Compliance Updates

The 2025 code aligned Portland's local requirements more closely with the 2010 ADA Standards for Accessible Design, closing gaps that previously existed in the city's code.

Key Changes for Parking Lots

• Van-accessible spaces: Portland now requires that at least one of every six accessible spaces be van-accessible (96-inch minimum width with 96-inch access aisle), up from the previous one-per-lot minimum
• Surface requirements: Accessible routes from parking spaces to building entrances must maintain a maximum 2% cross-slope and 5% running slope — requirements that demand precision grading, especially on Portland's hilly terrain
• Signage and marking: New lots must use the 2010 International Symbol of Accessibility. Restriping projects on existing lots must update to the current symbol

These requirements are particularly relevant for properties in hilly neighborhoods like the West Hills, Marquam Hill, and the Terwilliger curves, where achieving compliant slopes requires careful site design. Read our ADA parking compliance guide for detailed requirements.

Central City Plan District: Additional Requirements

Properties within Portland's Central City Plan District — which includes Downtown, the Pearl District, the Central Eastside, South Waterfront, and Lloyd District — face overlay requirements beyond the base code.

Design Review for Paving

New surface parking lots and significant parking lot modifications in the Central City require design review. This process evaluates:

• Pedestrian connectivity through and around the lot
• Landscaping and tree canopy coverage
• Screening of parking areas from public streets
• Lighting standards for safety and light pollution control

Design review adds 4-8 weeks to the permitting timeline and requires architectural-quality site plans. Cojo coordinates with local design professionals to prepare compliant submittals for Central City projects.

Green Building Requirements

The Central City also has green building requirements that can affect paving material choices. Projects over certain size thresholds must achieve specific sustainability benchmarks, which may favor permeable pavement, recycled asphalt content, or high-albedo surface treatments to reduce heat island effects.

Residential Paving: What Homeowners Need to Know

Most residential paving projects in Portland are straightforward, but the 2025 code includes provisions that homeowners should understand.

Driveway Approach Permits

Any new or modified driveway approach — the section where your driveway meets the public street — requires a permit from the Portland Bureau of Transportation (PBOT). The 2025 code maintained existing width limits:

• Single-family residential: Maximum 24-foot approach width
• Multi-family: Maximum 30-foot approach width (or two 18-foot approaches)
• Corner lots: Approaches must be set back at least 25 feet from the intersection

PBOT reviews approaches for sight distance, pedestrian safety, and impacts on street trees. If a street tree is in the way, you will need to work with Portland Parks and Recreation — tree removal permits have become more difficult to obtain under the 2025 code.

Setback and Lot Coverage

Portland's zoning code limits impervious surface coverage on residential lots. In most residential zones:

• R5 (standard lot): Maximum 45% building coverage, but total impervious surface (including driveways, patios, and walkways) is evaluated under stormwater rules
• R2.5 and R1 (attached housing zones): Higher coverage allowed, but stormwater management becomes critical

If you are planning a large driveway or adding parking pads on a smaller lot, the cumulative impervious coverage may trigger stormwater requirements.

Portland's Clay Soil Factor

Portland's building code changes interact with the city's challenging soil conditions. The Willamette Silt and Portland Hills Silt formations — heavy clay soils that dominate the metro area — create specific engineering requirements for paved surfaces.

The 2025 code did not change geotechnical requirements directly, but the expanded stormwater infiltration mandate puts more emphasis on understanding soil permeability. Clay soils have very low infiltration rates (often less than 0.5 inches per hour), which means:

• Infiltration-based stormwater systems may not be feasible on many Portland properties without engineered amendments
• Detention-based systems (which hold water and release it slowly) are often required instead
• Permeable pavement over clay soils requires an engineered stone reservoir base with underdrains

Cojo tests soil conditions before designing any paving project in Portland. We have worked on hundreds of sites across the metro area and understand how Portland's geology affects both structural pavement design and stormwater compliance. See our article on Portland's clay soil challenges for more detail.

Permit Timeline and Cost Planning

Understanding Portland's current permit landscape helps you plan realistic project timelines.

Typical Permit Timelines (2026)

| Project Type | Permit Required | Typical Timeline | |---|---|---| | Driveway resurface (same footprint) | None | Immediate | | New driveway approach | PBOT right-of-way permit | 2-4 weeks | | New residential driveway | BDS development permit | 3-6 weeks | | Commercial parking lot (under 500 sf new) | BDS commercial permit | 4-8 weeks | | Commercial parking lot (over 500 sf new) | BDS + BES stormwater review | 8-16 weeks | | Central City parking lot | BDS + Design Review | 12-20 weeks |

Permit Fees

Portland permit fees are based on project valuation. As a rough guide:

• Residential driveway permits: $300-800
• Commercial site development permits: $2,000-8,000
• Design review (Central City): $3,000-6,000 additional
• Stormwater review: $1,500-4,000 additional

These fees do not include the cost of required plans and engineering documentation, which typically run $2,000-5,000 for commercial projects.

How Cojo Handles Portland's Code Requirements

We manage code compliance as part of every Portland project:

1. Pre-project assessment: We evaluate your site against current code requirements before providing a quote, so there are no surprises
2. Permit coordination: We prepare permit applications and coordinate with BDS, PBOT, and BES as needed
3. Stormwater design: We design compliant stormwater systems integrated with your paving project
4. ADA compliance: Every commercial project includes ADA review and compliant construction
5. Inspection coordination: We schedule and manage required inspections throughout construction

Portland's permitting landscape is complex, but it should not prevent you from getting the paving work your property needs. Contact Cojo for a project assessment that accounts for all applicable code requirements.