Accessory Dwellings

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Propel Studio ADU Profiles

If you’d like to learn more about Propel Studio, please check out ADU Designer Profile: Propel Studio


ADU #1   The Screen – Sustainable ADU  

  • Square Footage:  721 SF
  • Year Built:  2017
  • Architect/Designer:  Propel Studio
  • Builder:  JLTB Construction  
  • Type of ADU: Detached New Construction
  • Current Use: Owner’s Primary Residence
  • Ballpark Cost: $185,000

The Project: The client’s goal was to build a new, custom-designed ADU to better accommodate the needs for their family of 3. For example, the existing house was pretty dark and felt small because it had so many walled off spaces. The existing house is also lifted above grade with several sets of stairs, making accessibility difficult long-term. By vacating the primary residence, the family has flexibility to accommodate additional family on site as well as renting the main house for additional income. The clients were also sustainably focused and wanted a high-performance, energy-efficient ADU with a healthy indoor environment.

The Challenges:  This property is located in the Eliot Conservation District and therefore triggers either a Historic Resource Review -or- strictly adhering to the prescriptive design requirements of the Community Design Standards. Historic review adds another layer of work to a typical ADU design process which would increase the time it takes. If we chose to pursue a historic review, it would occur after the schematic design has already been developed to the client’s preferences, but before proceeding with structural engineering and detailed construction documents. If the historic review doesn’t approve a design, this could mean a re-design effort, adding additional architectural work to meet the city staff requirements. Unfortunately, historic review is also subjective and changes depending on the city staff assigned to the project.

Pursuing the historic review for the new accessory structure would follow the Portland’s Type 1 land use review procedure – a 35 day process after payment of a $5,618 fee to the city of Portland. We determined that this was not worth the time and costs associated with it, especially because there was no guarantee we’d have any more design freedom. Instead, we decided to design the project following the Community Design Standards. These standards restrict design somewhat, but are predictable and don’t add to project costs or schedule. At the end of the day, we were able to meet the design standards while still providing the clients an open modern interior with some beautiful exterior spaces, materials, and details.

The Solutions:

The ADU design references a traditional gable roof in form, however the indoor spaces are L-shaped, leaving one quadrant as a private, shaded, outdoor space with connections to the interior great room. The living, dining, and kitchen needs are served in a large and flexible “great room.” Vaulted ceilings, exposed glulam wood beam, and rhythmic windows are used to give the great room a bright and open feel.  The back of the ADU consists of two bedrooms flanking a shared bathroom. A small attic storage space was incorporated above the bathroom ceiling to house the utilities

The ADU features many sustainable design enhancements, including a high efficiency building envelope, FSC certified wood products, an energy efficient mini-split mechanical system, high efficiency LED lighting, occupancy controlled ventilation, and low or zero VOC/and low formaldehyde products selected throughout.  The exterior wall assemblies were designed to manage moisture to avoid issues many older Portland homes experience with poor air quality.  The slab-on-grade construction offers barrier-free ADA accessibility throughout the unit, allowing aging-in-place.


ADU #2 – The Carve-Out | Northwest Modern ADU

  • Square Footage: 800 SF
  • Year Built:  2015
  • Architect/Designer:  Propel Studio  
  • Builder:  Gibson Builders – Leon Gibson
  • Type of ADU:  Detached New Construction
  • Current Use:  Long-Term Rental
  • Ballpark Cost:  $175,000

The Project:

Our client was looking to initially build the ADU as an investment rental unit. However, they wanted to have the flexibility to accommodate many scenarios as their family grows, including them possibly moving into the ADU to downsize after kids move out.

The Challenges:

This ADU is located on a lot measuring approximately 80’ wide x 210’ deep in the Cully Neighborhood of NE Portland. The desire was to locate the ADU in the back corner of the lot to offer the most privacy and buffer between the two units. The challenge on such a large lot with the building in the very rear is fire protection. Fire department trucks can only protect structures up to 150’ away due to hose length. Being located so far from the street meant the ADU needed to have its own fire protection sprinkler system – including a water tank & pump.

The Solutions: This northwest modern ADU puts a contemporary twist on a traditional craftsman bungalow aesthetic, utilizing natural wood siding and exposing the wood beam interior structure. The inherent beauty of natural wood and material connections drove the design for this Accessory Dwelling Unit. The form of the small dwelling has been carved away at the corners, creating covered outdoor areas for the main entrance and the back patio. The exterior aesthetics balances cool bluish-gray siding with the natural warmth of vertical cedar planks in the carved out areas. Delicate details throughout the project, such as the split columns at the exterior terraces and the interior steel spiral stairs and railings, emphasize the tectonics of the architecture.

The interior offers a simple, open plan with a single, vaulted, great room that houses the kitchen, dining and living areas. The bedroom and bathroom are tucked to one side, leaving large windows, skylights and sliding glass door bringing ample natural light into the main living spaces. A loft space was built above the bedroom and bathroom, creating a bonus space that could be used as a second TV/Living room, home office, or place for kids to play. Sustainable features include a radiant heated slab, a super-insulated envelope with continuous insulation, on-demand hot water, and ample thermal mass, lowering year-round energy costs.


ADU #3 – The Frame | Contemporary ADU

  • Square Footage: 671 SF
  • Year Built: Under Construction
  • Architect/Designer: Propel Studio  
  • Builder: Severin Holden Construction
  • Type of ADU: Detached New Construction
  • Current Use: The ADU will become the owner’s primary residence
  • Ballpark Cost: $170,000

The Project: Our client wanted an ADU with a modern design aesthetic and a large open space to cook and entertain visiting family and guests. We were also tasked with designing a single story unit so that the client’s aging parent could move into the unit once it made sense for the family. Easy access and visual connection to the yard were also important, while maintaining privacy from the primary house.

The Challenges: The back yard is fairly large, however, we wanted to protect a large tree located right in the center of the available space – which was kind of tricky. In response to our clients needs – as well as restrictions and requirements (tree root protection, setbacks, and fire separation requirements) – the design solution was a tight fit on the site.

The Solutions:

With the recent loosening of stylistic restrictions of Portland’s ADU zoning requirements, clients are starting to challenge us to design ADUs with a more modern aesthetic. This project is a contemporary twist on a traditional gable roof form. The gable roofed main volume of the house is wrapped in continuous dark bronze standing seam metal cladding from the roof down the walls. A private master suite wing appears as a modernist wood clad box intersecting the main volume to form an L-shaped plan. The design is a dynamic play on form and contrast. Both the bedroom and living room have large glass doors that open up onto the deck that sits in the crux of the L-shaped plan.

The great room has floor-to-ceiling glass on one gable end and includes high windows on the other gable-end, above the kitchen shelving. Vaulted ceilings are uninterrupted from end to end for a length of  35’, creating an impressive open and airy volume for the great room. This was accomplished using a concealed structural steel ridge beam and steel moment frames to maintain a thin gable-end profile.

About linamenard

Hi. My name is Lina Menard and I'm a small house dweller, designer, blogger, and builder. I'm currently collecting ADU Case Studies for Through my company Niche Consulting LLC, I help people design and build the home (and life) of their dreams! I also tell my stories about simple living in small spaces - like a travel trailer, a yurt, a backyard cottage, and tiny houses on wheels - at Niche News.

One comment on “Propel Studio ADU Profiles

  1. theprojectplace
    February 1, 2018

    Reblogged this on the project place.

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