Compatibility in a Conservation District

By Jonathan Konkol, AICP; Eliot LUTC Vice Chair

Picture of a cream and wood building with a white truck parked in front
Duplex under construction in the Boise Neighborhood. Photo credit Jonathan Konkol.

There’s a perennial debate in the design and planning world about what kinds of standards are appropriate for new development in a historical context. Should new buildings blend in, or stand in contrast? Is it “phony” or “context- sensitive” to replicate historic vernacular forms?

This winter the Eliot Land Use & Transportation Committee (LUTC) heard a presentation from City staff regarding Portland’s Conservation Districts. Over the course of the conversation, while trying to articulate what I thought was most important about compatibility and integration of new buildings with existing fabric, I hit upon the phrase “Diagrammatic Compatibility.” This idea really connected because it stands in contrast with other conventional notions of compatibility. It gets at a deeper level of design than the very literal, yet superficial approach to compatibility that consists of selecting matching materials, colors, etc. to those on nearby existing buildings. This is the extent of what some design codes prescribe.

Diagrammatic compatibility can be defined as matching the key schematic elements of composition for a block or district. It includes approximate massing, proportions, overall height and setback lines, the relationship of the building to the street, to its site, and the rhythm of buildings along the street in relation to one another. This is distinct from the particular vernacular style of the building (Queen Anne, Tudor, Craftsman, Prairie Style, Streamline Moderne, etc.). The latter refers to the particular visual language of a building, while the former refers more to what it’s saying in a given language.

Often a new building is neither stylistically nor diagrammatically compatible, in which case it’s easy to be confused about why it feels like a bad fit. My argument is that diagrammatic compatibility is far more important than stylistic compatibility.

It is my contention that a house or building that is stylistically dissimilar yet diagrammatically compatible is far more appropriate and responsive to its urban context than one that is nominally of the same style while exhibiting a very different configuration, massing, relationship to site, etc.

Drawing of five building in a row: the first four are identical (green with a pointed roof) while the fifth is different (an orange building with a flat roof)
Seattle Victorians and their new Neighbor

One of the best illustrations of the concept I’ve seen is this row of Queen Anne Victorians in Seattle’s Central District which was joined by a new neighbor fairly recently. As you can see, the newcomer is composed in a completely different idiom, yet it continues the rhythm of the row of houses that came before it.

What matters here is the overall proportion of the building, its pat- tern, and placement of windows and doors, its overall form factor, and its relationship to the site and to the street.

Photo of a blue house, taller than the houses on either side.
What “historical” typology is this?

By comparison, this new addition to the Boise neighborhood at NE Fremont & Rodney is at least nominally compatible, in as much as it is composed in a “historical” vernacular. It has old-timey details, like (pseudo) divided pane windows, horizontal lap siding (as opposed to the current favorite, Hardie Panel in 4×8 sheets), and a steep-pitched roof. However, something about it just doesn’t look right. That’s because its particular configuration, large house with the main floor elevated above the ground plane on top of a two car garage, with a wide driveway taking the place of a lawn and stoop, is something that doesn’t have any historical precedent. It’s an entirely new configuration, dating to within my lifetime. There are a few early 20th-century houses that have basement garages, but they remain subordinated to traditional site arrangement principles. Finally, I’d argue that vernacular ways of building, which are some- times referred to as “historical” are not anachronisms at all. They are still perfectly valid ways of building. Existing examples constructed in pre-war vernacular are highly functional and beloved by their residents. I personally resided in one of Portland’s oldest houses, the James Duthie house in the Buckman neighborhood. The house has been partitioned into a triplex with upper, ground floor and basement units. I lived in the upper unit for over six years. I found it both convenient and enjoyable, not to mention spiritually uplifting to experience continuity with generations of residents reaching back to the Lincoln administration.

In the original blog version of this article, I profiled a recent courtyard townhouse project that demonstrates that contemporary buildings with a vernacular design vocabulary aren’t necessarily “fake history” – they’re just good, carefully detailed, thoughtfully designed buildings. There’s absolutely nothing obsolete about the overall composition or architectural expression here. Most importantly, the diagrammatic form of the building is entirely consistent with the Prewar, non-auto-centric forms we want to encourage when new development occurs in Eliot. As Stuart Brand explained in his book How Buildings Learn, the most enduring part of a building’s design is its relationship with its site. That, in turn, is the basis of an enduring building.

This article, which includes numerous diagrams and photographs that wouldn’t fit into print format can be found at my urban design website,