Accessory Dwellings

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Asmund & Jenny’s ADU

  • Neighborhood: King, Portland OR
  • Type: New detached
  • Use: Short term rental (for now)
  • Size: 330 SF
  • Year completed: 2017
  • Owners: Asmund & Jenny Tweto
  • Contractor: Asmund
  • Architect: Asmund
  • Cost: $95,000 hard cost + 1,000 hours of design and construction


Asmund and Jenny had been considering building an ADU for quite a while and finally decided to take the plunge at the end of 2016. They were drawn by the potential for passive income, the need for more space for their growing family and guests, and they wanted to lock in the SDC fee waiver benefit before its scheduled expiration. They were particularly drawn to the short–term rental model to maintain the most flexibility.

Both architects, they were well equipped and excited for the design process and knew it would make a fun winter project. Capitalizing on experience gained working as a designer and project manager for a design-build contractor, Asmund decided to tackle the construction himself and committed full-time to the construction effort starting in March of 2017. The ADU was completed by November 2017 and is currently for rent on AirBnb.  Asmund is now practicing architecture independently, specializing in small homes and ADU’s. Please feel free to reach out to Asmund with any questions about this project or if you would like to discuss your own project.






The construction process went smoothly and was completed in about 6 months. The most challenging part of the construction process was site access. The property has no driveway and no on-street parking on their side of the street, which was busy enough to make any deliveries extra challenging. Machinery was carefully brought in through the neighbors driveway, dirt had to be removed by wheelbarrow to a dumpster in the street, and all materials had to be hand carried from the street.

The project cost was about $95,000 in hard costs and Asmund spent approximately 1,000 hours on design and construction. He estimates the cost if built by a contractor would be $170,000-$190,000.


The principle challenge of the design was to create a spacious feeling one-bedroom unit with a small enough footprint to retain usable outdoor spaces for their vegetable garden, a small lawn and a patio. The ADU was carefully sited to maintain privacy and separation from the main house and associated outdoor spaces while still feeling open and welcoming. The cottage opens to a sunny patio on the south with minimal windows on the other exposures to maintain privacy. In order to minimize the site impact, the ADU was designed to fit the exemptions the city offers allowing smaller buildings within property setbacks.

Tall ceilings, large south-facing windows, large skylights, and a space conscious floor plan keep the space feeling generous despite the small 330 SF of interior area.




A vaulted space with south-facing windows and a floating bay window make the most of the limited space available for the kitchen and living room. A wall hung toilet and sink in the bathroom allowed for minimal bathroom dimensions. A light tube over the shower keeps the windowless bathroom feeling bright and welcoming. The bedroom is behind the bathroom and is sized for a queen size bed and a small desk. An exposed wood structure and ceiling over the bathroom and bedroom creates a storage loft above.





The heating system is an open direct hydronic heating system utilizing the same tankless hot water heater as the domestic hot water. The building relies on passive ventilation and thermal mass to keep cool in the summer. The envelope features advanced framing with blown in cellulose insulation and a rainscreen under cedar open-jointed and painted cedar siding. A metal roof was selected for appearance, longevity and recyclability. Windows are Loewen Fir interior/clad exterior. The interior trim and millwork is VG Fir. The kitchen counter is a custom walnut butcher block from Brace and Bit, and the cabinets are plastic laminate over Baltic birch by Artisan woodworking.


About asmundtweto

6 comments on “Asmund & Jenny’s ADU

  1. Daniel Bachhuber
    July 3, 2018

    Great design!

  2. J Dirking
    November 4, 2018

    Inspiring! I loved the built in window seat, and the generally warm feeling from the natural look of the wood and all of the light. Beautiful job and full of elements I hope to incorporate into my own ADU in the SF Bay Area. Kudos for doing it yourself, too, that is a lot of work!

  3. Amandine Rambert
    February 5, 2020

    Hi ! I’d like to use one of your photos to promote infill housing in Quebec (Canada). I work for a NGO. Who should I talk to ?
    Thanks !


Comments are closed.


This entry was posted on July 3, 2018 by in 399 SF or Smaller, ADU Designer, ADU Professional Profiles, Detached, Projects.
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