Accessory Dwellings

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Birdsmouth Design | Build ADU Profiles

To learn more about this company, check out Design-Builder Profile: Birdsmouth Design | Build. For a more in-depth look, check out Barbara Gundle’s ADU: A 2-Story Garage Conversion

ADU #1 – Melrose ADU

  • Square Footage: 766
  • Year Built: 2013
  • Architect/Designer: Mary Hogue, MkM Architecture
  • Builder: Birdsmouth Design Build
  • Type of ADU: Attached second story
  • Current Use: Long-term rental
  • Ballpark Cost: $196,000

The Project: To create this ADU, we removed the entire second story of the existing house and built a new gable roof with 2 dormers to create a 2 bedroom, 1 bath ADU with a large deck and French doors. The client wanted to supplement their income as they often travel, and the ADU would be a source of income to help with the mortgage when they are not in town.

The Challenges: The house was located on a small one-way street on a slope, and the neighboring houses were very close w/ large mature trees all around. It took a large crane and some dexterous footwork to get all the materials in position. The existing house had old, not to code plumbing and electrical, along with some missing structure that had to be upgraded. The clients also elected to live in the house during all of the construction (while the entire roof was gone!)

The Solutions:

  1. The demolition and framing were done very quickly to avoid the time the roof was off the house and the street had to be closed off. This required cranes, a large crew of framers and a deconstruction team.
  2. The favorite feature for the homeowners was the ‘Perch’ as the clients referred to it: a deck off the master bedroom accessed from a door in a gable that overlooks the city’s rail yards and great view of downtown.
  3. A custom integrated drain system carried water away and a TPO membrane under the hardwood deck kept the living space below protected.

ADU #2 – Emerson ADU

  • Square Footage: 798
  • Year Built: 2015
  • Architect/Designer: Ben Valentin, Birdsmouth Design Build
  • Builder: Birdsmouth Design Build
  • Type of ADU: Attached, new construction
  • Current Use: Owners primary dwelling
  • Ballpark Cost: $225,000

The Project: This ADU is certified as both a Passive House and an Earth Advantage Certified Net Zero Energy Home. It is one story with 2 bedrooms, one bath, and vaulted ceilings in main area. The ADU is attached to the rear of a 3 bedroom, 2 bath main residence. It has a fully landscaped private back patio accessed from large French doors. It’s a modern design with universal design features, including no curb on the shower, grab bars, low thresholds, etc. The client’s goals are to promote local investing on healthy, environmentally conscious development for greater density and community connection. The clients website for more info is at:

The Challenges: The lot was zoned R2.5A which allowed for multiple residences which coincided with the clients density goals. The lot, however, was too small to accommodate this goal. We had to take advantage of a living roof and a permeable concrete driveway to offset the pervious area requirements in order to fit a two unit building on the site. The original design had called for a retrofit/addition to the existing 1997 single story home. Once deconstruction was completed it was discovered that the entire bottom of the sheathing was covered in black mold and the foundation lacked any reinforcement. We had to demolish the entire structure and redesign a new home with an attached ADU on the site. The city of Portland also made the permitting process difficult and added unnecessary costs to the project by requiring gypsum fire blocking to all the walls of the building and a vapor impermeable insulation to a critical area of the living roof, making it more prone to failure and adding significant costs.

Description of the Solutions:

  1. The house is heated with only 3 small wall mounted hot water radiators that are connected to one water tank that also supplies all of the domestic hot water needs. This tank is heated by an air-to-water heat pump that gets over 500% efficiency. This coupled with one of the most efficient heat recovery ventilators available, 100% LED lighting, and super efficient appliances makes this building one of the most energy efficient residential buildings in the United States.
  2. The beautiful living roof and roof deck, along with native planting landscaping should provide for a great connection to the outside.
  3. The ventilation air is continuously supplied and filtered through a 13 micron filter, making for extremely high indoor air quality. People with environmental sensitivities or allergies should have no complications in this building.

ADU #3 – Gundle ADU

  • Square Footage: 480
  • Year Built: 2015
  • Architect/Designer: Jack Barnes, Jack Barnes Architects
  • Builder: Birdsmouth Design Build
  • Type of ADU: Garage Conversion
  • Current Use: Short-term rental
  • Ballpark Cost: $150,000

The Project: This 1 bedroom, 1 bath ADU was created by converting a 2-story garage. The bedroom and bath are on the main level with the kitchen and living areas on the second story. The existing garage had some rot and odd framing, but the slab was in good condition and was a good candidate for conversion. The client is intending to use it for a short-term rental for a few years, and plans to eventually live in the ADU and rent out her main house.

The Challenges: The ADU is in the Irvington historic area, and due to this we had to match the exact siding and exterior details of the main house. This included custom knee braces, and custom milled wood tongue and groove siding. This added a premium to the siding costs. There was also a party line sewer that had to be disconnected and a new sewer line run to the ADU. We discovered after cutting into the slab that it was 8-10” thick! Typically it would be 4.” It was a tight budget, but through some good work with the client and architect we were able to keep it within the budget goals for the client.

The Solutions:

  1. Using a spiral staircase saved a lot of room in the small ADU.
  2. The bath is a ‘wet room’ style bath with a shower draining into a floor drain and plaster was used on the walls in lieu of tile. This gave it a nice hand crafted feel, while also saving on costs.
  3. A simple mini split heat pump for heat and AC was employed and kept the project efficient and simple.
  4. The client chose some nice finishes and accentuated the walls with her photography work that made the place look great!

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 “Birdsmouth Design | Build ADU Profiles

  1. Pingback: ADU Design-Builder Profile: Birdsmouth Design | Build | Accessory Dwellings

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This entry was posted on February 26, 2016 by in ADU Design-Builder, ADU Professional Profiles, ADU Profiles, Projects and tagged .
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