Portland homeowners filed about 100 ADU permit applications, covering 112 units, between January 1 and November 5, 2026. More than half were new detached ADUs, and detached units, garage conversions and units built over or beside a garage together made up about 80% of all ADU permits, including basement conversions. Montavilla led every other neighborhood with 9 applications.
This post breaks down what those permits show: which types of ADUs Portland homeowners are building, where they are building them, how applications moved through the year, and how basement projects fit in. All figures come from City of Portland permit records.
Lamont Bros. is a design-build remodeling company based in West Linn, Oregon, founded in 2008, with more than 850 completed projects across the Portland metro area and Southwest Washington. We pulled this data because homeowners ask what other people are building before they decide what to build themselves. If you are comparing ADU types and budgets, our guide to the types of ADUs and what they cost goes deeper on each one, and the ADU cost calculator gives you a starting range for your own property.
A new detached ADU, a separate small home in the yard, is the most common choice. Of the 100 ADU permit applications filed in 2026 through November 5, 54 were for new detached ADUs. Garage conversions came next at 22, and 12 more were new units built over or beside a garage or shop. Another 11 basements were converted to ADUs under permits filed as alterations, which brings the combined total to 111.
| ADU type (as permitted), combined picture | Permits | Share of combined total |
|---|---|---|
| New detached ADU | 54 | 49% |
| Garage conversion | 22 | 20% |
| New unit over or beside a garage or shop | 12 | 11% |
| Basement converted to ADU (filed as an alteration) | 11 | 10% |
| Other outbuilding or space conversion | 5 | 5% |
| New attached ADU | 4 | 4% |
| New modular ADU | 3 | 3% |
| Total | 111 | 100% |
The 100 ADU permits cover 112 units because 12 of the applications were for more than one unit. Detached units, garage conversions and units over or beside a garage together account for 88 of the combined 111 permits, which is about 80%.
If your starting point is a garage, our guide to converting a garage into living space explains what that project involves.
ADU permits in 2026 are spread across the city, with the most applications in Montavilla (9). Concordia, Roseway and Hazelwood each had 4. Arbor Lodge, Woodstock, Richmond, Powellhurst-Gilbert, Ashcreek-Crestwood, Mt. Scott-Arleta, Mill Park and Parkrose each had 3.
The map shows the 87 of 100 permits that have a recorded location. 13 permits have no neighborhood recorded, so neighborhood counts are a minimum. A few things to keep in mind when reading them: the counts are applications, not finished units, and a neighborhood with a few more permits than another is not a meaningful difference at this sample size.
Applications peaked in spring and again in early fall. April had the most with 16, followed by May (14), September (14), June (13) and October (11). January (4) and July (4) were the slowest months, and November is partial, counted only through November 5.
Treat the monthly pattern as a signal, not a rule. With about 100 applications for the year, a handful of permits can move a month up or down. If you are planning a build, the timing that matters more is how long design takes before you apply, which is usually a couple of months or more.
Basement conversions are tracked separately from ADUs in the permit data, because most are filed as residential remodels of a single-family home. Looking at basement-focused residential permits issued from January 1 to November 9, 2026 (excluding foundation work and demolitions), 396 permits in total, 11 were for a basement converted to an ADU, 8 more were other ADU-related work, and 23 were explicitly labeled "not an ADU." The rest were other basement work.
That means the 100 ADU permits above understate how many basements are becoming living units. A basement with a kitchen, a bathroom and a separate entrance can function as an ADU even when the permit calls it a remodel. Portland has specific rules about what counts as an ADU, including plumbing and ventilation for a separate kitchen and bath and the location of the entrance, so check the current Portland ADU rules before you plan one.
Not much that you can rely on. Permit records include a valuation, but it is the figure the applicant states, and in this data many are round or repeated numbers that do not track the size of the project. So this post does not report a cost per ADU from permits.
For a more useful view of cost, see how cost differs by ADU type and what an all-in ADU budget needs to include. If you are planning to borrow, our ADU financing guide covers loan options.
The data comes from City of Portland permit records available through Portland Maps. We combined the City's ADU permit reports for fiscal years 2026 and 2027 and kept applications created from January 1 to November 5, 2026. We excluded revisions, solar and mechanical-only permits, and permits with no new unit. Each application was then grouped by type from its permit description and work type. Neighborhood comes from the City's record; 13 permits have none. The basement analysis uses the City's issued residential building permits for January 1 to November 9, 2026.
The two datasets use different cutoffs and measures: ADU permits are applications created through November 5, 2026, while basement conversions are issued permits through November 9, 2026. The basement classification is approximate, because it is based on keywords in permit descriptions rather than a permit type the City assigns.
Permit counts show what people applied for, not what was finished, and descriptions are written by applicants, so some permits could fall in a different group under a different reading. The data will keep changing as new applications arrive.
The permit data suggests that most Portland homeowners who move forward are choosing a detached unit or a garage-based project. A detached unit offers the most privacy and the most flexibility, and a garage conversion uses space you already have. Both need a clear scope and a firm price before you commit, because permits, utility connections and site work can change the total. Our Portland ADU builders page shows how Lamont Bros. approaches these projects.
Lamont Bros. works with homeowners who want a design-build ADU in the Portland metro area and Southwest Washington, including Lake Oswego, West Linn, Oregon City and Beaverton. Homeowners choose Lamont because one cohesive team handles the design, the fixed-price construction contract and the build, and because Lamont offers financing and a three-year limited workmanship warranty. Schedule a consultation to get started and talk through your property, your goals and your budget.
About 100 ADU permit applications, covering 112 units, were filed in Portland between January 1 and November 5, 2026, according to City of Portland permit records. Some applications covered more than one unit, which is why the unit count is higher than the permit count.
The new detached ADU is the most common type. It made up 54 of the 100 ADU permits filed in 2026 through November 5. Garage conversions were next at 22 permits, followed by units built over or beside a garage or shop at 12.
Montavilla had the most ADU permit applications in 2026 with 9. Concordia, Roseway and Hazelwood each had 4. The counts are small, so differences between neighborhoods of one or two permits are not meaningful.
Mostly not. Many basement conversions are filed as remodels of a single-family home, so they do not appear in ADU permit counts. Of 396 basement permits issued in 2026 through November 9, 11 were for a basement converted to an ADU, 8 were other ADU-related work and 23 were labeled "not an ADU."
No. Permit valuations are stated by the applicant and often do not reflect the real cost of construction. Lamont Bros. recommends getting a design consultant's estimate for your property or using the ADU cost calculator for a starting range.