Property Reclassification & Correction of Details

Interested in what reviews are currently done on contributing vs. non-contributing houses? See this quick one page guide from the City.

As the proposal to become a Historic District progresses through the State and Federal levels, homeowners who disagree with the way that their property was described or designated may submit information to AECOM for review (SHPO will be copied). SHPO has asked that we batch this information into groups to simplify this process for them. Please fill out the form below to submit inaccuracies or discrepancies.

Photos & drawings can be separately emailed as "evidence"; before and after photos are particularly helpful. Please click the link at the bottom to email these documents – it would be ideal to send a single PDF with all of your materials, using your property address as the document name (multiple files/documents will be more cumbersome for us to manage). Please email all materials to

Please see this memo, dated 2.24.17 from Jason Allen, the Survey and Inventory Program Manager @ SHPO about submitting corrections and their final acceptance date of April 3


We will send batches of property corrections to SHPO every Monday until Monday, April 3rd.  There is a bit of processing on our end to format, so corrections must be received by 12 pm on the preceding Sunday to make it into the batch on Monday.  The last corrections will need to be received by us by Sunday, April 2nd at noon.

Once a Historic District is in place, changing a property from "contributing" to "non-contributing" is a more complicated process administered by the Bureau of Planning and Sustainability and involves a hearing in front of the Portland Historic Landmarks Commission followed by a review by the State Historic Preservation Office. Please see the National Register Reclassification Form for details.


From the National Park Service National Register Bulletin 16A:

A contributing building, site, structure, or object adds to the historic associations, historic architectural qualities, or archaeological values for which a property is significant because it was present during the period of significance, relates to the documented significance of the [historic district], and possesses historic integrity or is capable of yielding important information about the period.

A noncontributing building, site structure, or object does not add to the historic architectural qualities, historic associations, or archaeological values for which a property is significant because: it was not present during the period of significance or does not relate to the documented significance of the property; or due to alterations, disturbances, additions, or other changes, it no longer possesses historic integrity or is capable of yielding important information about the period.

From the National Park Service National Register Bulletin 15:


A district possesses a significant concentration, linkage, or continuity of sites, buildings, structures, or objects united historically or aesthetically by plan or physical development.


A district derives its importance from being a unified entity, even though it is often composed of a wide variety of resources. The identity of a district results from the interrelationship of its resources, which can convey a visual sense of the overall historic environment or be an arrangement of historically or functionally related properties. For example, a district can reflect one principal activity, such as a mill or a ranch, or it can encompass several interrelated activities, such as an area that includes industrial, residential, or commercial buildings, sites, structures, or objects. A district can also be a grouping of archaeological sites related primarily by their common components; these types of districts often will not visually represent a specific historic environment.


A district must be significant, as well as being an identifiable entity. It must be important for historical, architectural, archaeological, engineering, or cultural values.Therefore, districts that are significant will usually meet the last portion of Criterion C plus Criterion A, Criterion B, other portions of Criterion C, or Criterion D.


A district can comprise both features that lack individual distinction and individually distinctive features that serve as focal points. It may even be considered eligible if all of the components lack individual distinction, provided that the grouping achieves significance as a whole within its historic context. In either case, the majority of the components that add to the district's historic character, even if they are individually undistinguished, must possess integrity, as must the district as a whole. A district can contain buildings, structures, sites, objects, or open spaces that do not contribute to the significance of the district. The number of noncontributing properties a district can contain yet still convey its sense of time and place and historical development depends on how these properties affect the district's integrity. In archaeological districts, the primary factor to be considered is the effect of any disturbances on the information potential of the district as a whole.


For a district to retain integrity as a whole, the majority of the components that make up the district's historic character must possess integrity even if they are individually undistinguished. In addition, the relationships among the district's components must be substantially unchanged since the period of significance.

When evaluating the impact of intrusions upon the district's integrity, take into consideration the relative number, size, scale, design, and location of the components that do not contribute to the significance. A district is not eligible if it contains so many alterations or new intrusions that it no longer conveys the sense of a historic environment.

A component of a district cannot contribute to the significance if: it has been substantially altered since the period of the district's significance or it does not share the historic associations of the district.