A one-stop source about accessory dwelling units, multigenerational homes, laneway houses, ADUs, granny flats, in-law units…
This is the ADU profile information about the ADUs featured on the spring, 2015 city-wide ADU tour. I’ve taken out the addresses and the link to the mobile-friendly touring map page, but the rest of the information about each ADU is here.
-Kol , tour organizer
Rental
Type of ADU | basement conversion |
Architect/Designer | None |
General Contractor | Self general contracted |
Heating System | Electric cadets |
When did you start the design work? | 6/2014 |
When did you submit the plans to the City? | 7/2014 |
When did you start construction | 6/2014 |
When did you get your certificate of occupancy? | 2/2015 |
Total Square Footage | 750 |
Total Cost | $55K |
Cost/Square Foot | $73 |
Sweat Equity estimate | $25K |
Other special project costs |
Re-plumb the entire home, which was not as large of a project as it sounded since the plumbing runs in a straight line across the back side of the house ($2200) Separate electrical meters and service ($2900) Re-wiring to the first and second floors ($5900) |
Type of ADU | Basement Conversion |
Architect/Designer | self |
General Contractor | self |
Heating System | electric cadets |
When did you start the design work? | 7/2014 |
When did you submit the plans to the City? | 7/2014 |
When did you start construction | 2/2015 |
When did you get your certificate of occupancy? | 2/2015 |
Total Square Footage | 625 |
Total Cost | $25K |
Cost/Square Foot | $40 |
Sweat Equity estimate | $3K |
Other special project costs | The electric work ended up being more work than we anticipated. We ended up rewiring much of the house and PGE made us move our service from one side of the house to the other. We budgeted $2000 and it ended up being $5000. There was an existing bathroom in the basement that we thought was legal and incorporated in our plans. It turned out not to be, which meant we had to tear out some work and make it legal to today’s code, costing us an extra $2000. |
I am living in it myself and renting out the main house.
Type of ADU | Detached, new construction |
Architect/Designer | environs, environspdx.com |
General Contractor | environs, environsdpx.com |
Heating System | radiant slab – hydronic, gas fired tankless |
When did you start the design work? | 1/2014 |
When did you submit the plans to the City? | 6/2014 |
When did you start construction | 7/2014 |
When did you get your certificate of occupancy? | 1/2015 |
Total Square Footage | 640 |
Total Cost | $92K |
Cost/Square Foot | $143 |
Sweat Equity estimate | $5K |
Other special project costs | We had to upgrade the lateral water supply in the street to the house because of the water fixture count exceeding what was allowed for the 5/8″ meter/ 3/4″ city supply – $6000. |
Rental
Type of ADU | Detached, new construction |
Architect/Designer | Schuyler Smith polyphon.com |
General Contractor | Greenhammer, Greenhammer.com |
Heating System | Ductless minisplit, electric cadets |
When did you start the design work? | 2012 |
When did you submit the plans to the City? | 1/2013 |
When did you start construction | 2/2013 |
When did you get your certificate of occupancy? | 5/2015 |
Total Square Footage | 800 |
Total Cost | $155K |
Cost/Square Foot | $194 |
Sweat Equity estimate | $25K |
Other special project costs | Water upgrades, shared sewer, demolition of garage and foundation. |
We built our ADU for Megan’s mother, Pat. Pat occupied the house in November, 2014 and lives there now with her daughter Cindy.
Type of ADU |
Detached, new construction |
Architect/Designer |
Dustin Johnson, hivearchitecturestudio.com |
General Contractor |
Ryan Duble, rdbuildingdesign.com |
Heating System |
ductless minisplit |
When did you start the design work? |
12/2012 |
When did you submit the plans to the City? |
10/2013 |
When did you start construction |
11/2013 |
When did you get your certificate of occupancy? |
11/2014 |
Total Square Footage |
740 |
Total Cost |
$140K |
Cost/Square Foot |
$189 |
Sweat Equity estimate |
$30K |
Other special project costs |
Tearing down old garage and foundation ($2,500) sweat equity ($2,000) Upgrade of electrical service on main house to double meter system and run underground electrical to ADU ($5,000) Run underground gas line to ADU ($2,000) |
Type of ADU | New construction studio apartment over garage |
Architect/Designer | Stephan Williams, rainbowvalleyinc.com |
General Contractor | Rainbow Vally Design and Construction, rainbowvalleyinc.com |
Heating System | Gas fireplace |
When did you start the design work? | 3/2014 |
When did you submit the plans to the City? | 5/2014 |
When did you start construction | 8/2014 |
When did you get your certificate of occupancy? | 2/2015 |
Total Square Footage | 504 |
Total Cost | $140K |
Cost/Square Foot | $278 |
Sweat Equity estimate | $5K |
Other special project costs | The city required engineered supports for the vaulted ceilings. The additional cost for manufacturing metal brackets and installing them ($3,000) |
We are using the ADU as a guest space for family and friends and as a short term rental through Airbnb.
Type of ADU |
Detached, new construction |
Architect/Designer |
Carly Boynton, Grain Design Build |
General Contractor |
Stephen Smith, Design Build Portland, designbuildportland.com |
Heating System |
Electric radiant – Comfort Cove. WarmWire electric coils beneath the bathroom tiles. |
When did you start the design work? |
8/2013 |
When did you submit the plans to the City? |
9/2013 |
When did you start construction |
10/2013 |
When did you get your certificate of occupancy? |
11/2014 |
Total Square Footage |
300 |
Total Cost |
$128K (including the attached 170 ft workshop) |
Cost/Square Foot |
$272 |
Sweat Equity estimate |
$25K |
Other special project costs |
Design and costs included an extra 170 sq feet of storage/workshop space along with an additional half bath in the workshop, as well as construction of a bike shed in the yard for additional storage. |
Katie’s mother, Judy, lives in the ADU year round.
Type of ADU |
Garage Conversion |
Architect/Designer |
Design Build Portland, LLC, designbuildportland.com |
General Contractor |
Design Build Portland, LLC, designbuildportland.com |
Heating System |
Radiant hydronic |
When did you start the design work? |
8/2013 |
When did you submit the plans to the City? |
10/2013 |
When did you start construction |
12/2013 |
When did you get your certificate of occupancy? |
7/2014 |
Total Square Footage |
540 |
Total Cost |
$125K |
Cost/Square Foot |
$231 |
Sweat Equity estimate |
$0 |
Other special project costs |
Upgrade our water service ($5k) land use review ($2k) installed tankless hot water heater in main house to share with ADU for hot water/heating ($5k) buried our electrical connection because my mom hates to see wires ($2k). |
Primary residence
Type of ADU |
Detached, garage conversion |
Architect/Designer |
N/A |
General Contractor |
Don Kern |
Heating System |
Electric cadets |
When did you start the design work? |
5/2014 |
When did you submit the plans to the City? |
6/2014 |
When did you start construction |
6/2014 |
When did you get your certificate of occupancy? |
8/2014 |
Total Square Footage |
400 |
Total Cost |
$46K |
Cost/Square Foot |
$115 |
Sweat Equity estimate |
$3K |
Other special project costs |
N/A |
Primary residence. Read an extended blog post about this project here.
Type of ADU |
Detached, new construction |
Architect/Designer | |
General Contractor |
Dan Maust Construction |
Heating System |
Ductless minisplit, electric cadets |
When did you start the design work? |
12/2012 |
When did you submit the plans to the City? |
1/2013 |
When did you start construction |
3/2013 |
When did you get your certificate of occupancy? |
4/2015 |
Total Square Footage |
550 |
Total Cost |
$60K |
Cost/Square Foot |
$109 |
Sweat Equity estimate |
$30K |
Other special project costs |
Many of the costs seemed high but it was hard to put things in perspective as this is the only house I have built. I feel like you can’t really shop the construction costs around too much. All the good builders in Portland are busy so you really have to just accept that they are giving you somewhat of a fair price. When you don’t know the difference between expensive and fair it’s hard to swallow. I feel the costs are a little higher then they should be… just because ADUs aren’t normal and contractors are used to bidding larger houses. |
Primary residence
Type of ADU |
Detached, new construction with garage |
Architect/Designer |
Randal Groves |
General Contractor |
Jacob Flory |
Heating System |
ductless minisplit |
When did you start the design work? |
3/2013 |
When did you submit the plans to the City? |
6/2013 |
When did you start construction |
8/2013 |
When did you get your certificate of occupancy? |
1/2015 |
Total Square Footage |
792 |
Total Cost |
$200K |
Cost/Square Foot |
$252 |
Sweat Equity estimate |
$3K |
Other special project costs |
Oil tank removal, new sewer line, new electrical service, new sidewalks, new retaining wall, new driveway. |
This ADU will primarily be used as a short term rental. Having a space like this that we can use for family and friends when they come to Portland is great too and short term rentals allow us to ‘block off time’ when family is visiting. It makes a great birthday party venue too!
Type of ADU | Detached new construction, garage below. |
Architect/Designer | Dave Spitzer, DMS Architects, adupdx.com |
General Contractor | Jim Forristal |
Heating System | Rinnai gas wall furnace |
When did you start the design work? | 2/2014 |
When did you submit the plans to the City? | 4/2014 |
When did you start construction | 7/2014 |
When did you get your certificate of occupancy? | 1/2015 |
Total Square Footage | 374 |
Total Cost | $130K |
Cost/Square Foot | $348 |
Sweat Equity estimate | $40k |
Other special project costs | Demolition of old garage and foundation (3k)Land use adjustment (2k)Additional retaining wall, stairs and grading (5k) |
Studio. Addition to ADU conversion. Converted to ADU in 3/2015
Type of ADU | Addition to ADU conversion |
Architect/Designer | Constructive Form Architecture and Design LLC, constructiveform.com |
General Contractor | Citilites Builders, Inc |
Heating System | hydronic heating |
When did you start the design work? | 8/2010 |
When did you submit the plans to the City? | 11/2010 |
When did you start construction | 7/2012 |
When did you get your certificate of occupancy? | 1/2013 |
Total Square Footage | 500 |
Total Cost | $130K |
Cost/Square Foot | $260 |
Sweat Equity estimate | $20K |
Other special project costs | Tearing down old garage and foundation. Separating shared party sewer. |
Rental and we have two wonderful tenants. Read an extended blog post about this project here.
Type of ADU | Detached, new construction |
Architect/Designer | Das Chapin |
General Contractor | Das Chapin |
Heating System | Ductless minisplit |
When did you start the design work? | 1/2013 |
When did you submit the plans to the City? | 2/2013 |
When did you start construction | 2/2013 |
When did you get your certificate of occupancy? | 4/2013 |
Total Square Footage | 780 |
Total Cost | $50K |
Cost/Square Foot | $64 |
Sweat Equity estimate | $25K |
Other special project costs | Separated electrical service (not mandatory) ($4K) |
This project was built with a few goals in mind:
Read an extended blog post about this project here.
Type of ADU | Detached, above a workshop |
Architect/Designer | Self designed |
General Contractor | James Ray Arnold Greenbuilding, jragbc.com |
Heating System | ductless mini-split |
When did you start the design work? | 2007 |
When did you submit the plans to the City? | 12/2009 |
When did you start construction | 3/2010 |
When did you get your certificate of occupancy? | 10/2010 |
Total Square Footage | 546 |
Total Cost | $160K |
Cost/Square Foot | $293 |
Sweat Equity estimate | design, sourcing materials, construction, finding subcontractors, and swinging a hammer ($50K) |
Other special project costs | SDCs- they did this ADU just before the waiver. 😦 ($10K)upgraded water and sewer line, metal roof |
This is the second rental house on the property. Someday we may move into one of the two. We are currently renting the ADU long term and are recouping its cost.
Type of ADU | Detached, new construction |
Architect/Designer | R & B Design Studio LLC, RnBdesign.org |
General Contractor | EcoPowerNW, LLC. Norm Yonemura ecopowernw.com |
Heating System | Ductless minisplit |
When did you start the design work? | 4/2013 |
When did you submit the plans to the City? | 3/2014 |
When did you start construction | 4/2014 |
When did you get your certificate of occupancy? | 12/2014 |
Total Square Footage | 728 |
Total Cost | $187K |
Cost/Square Foot | $256 |
Sweat Equity estimate | $30K |
Other special project costs | Tearing down old garage. $3KNew dual meter base on front house. $5KRemove 4 good sized trees $4K |
Primary residence but also rent it short term for income while we travel/explore.
Read an extended blog post about this project here.
Type of ADU | Garage conversion |
Architect/Designer | Zenbox Design, zenboxdesign.com |
General Contractor | Zenbox Design, zenboxdesign.com |
Heating System | Natural gas fireplace |
When did you start the design work? | 7/2013 |
When did you submit the plans to the City? | 11/2013 |
When did you start construction | 11/2013 |
When did you get your certificate of occupancy? | 2/2014 |
Total Square Footage | 480 |
Total Cost | $85K |
Cost/Square Foot | $177 |
Sweat Equity estimate | all design, management and much of the labor- $20K |
Other special project costs |
land use adjustment ($2k) accordion door/wall ($11K) high end chef quality stainless appliances ($6K) spa-like wetroom bathroom ($7K) |
Type of ADU | Detached, new construction |
Architect/Designer | Ben Waichter benwaechter.com |
General Contractor | Nicholas MacDonald |
Heating System | radiant hydronic |
When did you start the design work? | 5/2012 |
When did you submit the plans to the City? | 1/2013 |
When did you start construction | 3/2014 |
When did you get your certificate of occupancy? | 2/2015 |
Total Square Footage | 800 |
Total Cost | $175K |
Cost/Square Foot | $218 |
Sweat Equity estimate | $40K |
Other special project costs | I had custom cabinets made and wood wall panels. I also chose hardward floors that were significantly more than carpet. Tile work was also a great cost. |
Work was permitted as an addition, not as an ADU. First floor is a pottery studio; second floor is a large bedroom and bath. City code prohibits an ADU and a “type 1” home occupation on the same single-dwelling site; we plan to convert it to a 2-story ADU if or when Adrienne retires from pottery teaching and production.
Type of ADU | Detached, new construction |
Architect/Designer | Ken Klos, kenklosarchitect.com |
General Contractor | Nicholas MacDonald |
Heating System | one wall mounted cadet forced-air heater and three wall-mounted radiant gas heaters (no fan or blower, to avoid stirring up clay dust in studio) |
When did you start the design work? | 7/2000 |
When did you submit the plans to the City? | 5/2001 |
When did you start construction | 9/2001 |
When did you get your certificate of occupancy? | 1/2003 |
Total Square Footage | 800 |
Total Cost | $185K |
Cost/Square Foot | $232 |
Sweat Equity estimate | 0 |
Other special project costs | Demolish existing concrete garage and retaining wall; major excavation for new larger garage and +/- 70’ long retaining wall along E property line; construct new retaining wall and storm drainage system; remove/decommission old underground oil tank; new electric service; expand gas service; exterior concrete slab and pavers for pottery kiln area; construct 10’x20’ rear deck on ground floor and approx. 100’ of perimeter good neighbor fence. |
At this time, we are not certain whether we will start out using it as a short-term rental. It is the perfect size and location for a short-term rental, which would help us to pay it off quicker. Ultimately,however, we would like to have a long-term renter living there who is part of our community.
Type of ADU | Attached- conversion of existing main floor footprint- “carve-out ADU” |
Architect/Designer | None |
General Contractor | RS Wallace Construction, rswallace.com |
Heating System | ductless minisplit |
When did you start the design work? | 4/2014 |
When did you submit the plans to the City? | 8/2013 |
When did you start construction | 9/2013 |
When did you get your certificate of occupancy? | 2/2015 |
Total Square Footage | 220 |
Total Cost | $65K |
Cost/Square Foot | $295 |
Sweat Equity estimate | $15K |
Other special project costs | Variance to the setback requirement ($2K)Also, because we gave our main floor bathroom to the ADU, we needed to build a new bathroom. And this isn’t just a regular bath–it is European-style wet bath (the entire bathroom is a shower). Despite its tiny size, things like a wall-mounted toilet and a linear trench drain are MUCH more expensive the more traditional fixtures. |
Long-term rental with the intention of housing an aging family member in the future.
Type of ADU | Detached new construction |
Architect/Designer | Design by Eamon Brennankos, plan drawings by Design Build Portland |
General Contractor | AK Bulders Inc. akbuildersnw.com |
Heating System | Electric cadet heaters |
When did you start the design work? | 8/2014 |
When did you submit the plans to the City? | 10/2014 |
When did you start construction | 11/2014 |
When did you get your certificate of occupancy? | 3/2015 |
Total Square Footage | 675 |
Total Cost | $100K |
Cost/Square Foot | $148 |
Sweat Equity estimate | $15K |
Other special project costs | None |
The ADUs will be sold as separate dwelling units; they are part of a six-unit shared space community. Read an extended blog post about this project here.
Type of ADU | Detached, new construction |
Architect/Designer | Jill Cropp, Studio Cropp, studiocropp.com |
General Contractor | Ethan Beck, Ethan Beck Homes, ethanbeckhomes.com |
Heating System | Ductless minisplit |
When did you start the design work? | 1/2014 |
When did you submit the plans to the City? | 7/2014 |
When did you start construction | 11/2014 |
When did you get your certificate of occupancy? | 6/2015 |
Total Square Footage | 610 |
Total Cost | $100K |
Cost/Square Foot | $164 |
Sweat Equity estimate | $0.Professional designer/developer full time. |
Other special project costs | Due to the fact that the ADUs are part of a larger development project, it is hard to parse out the exact costs. Construction alone (sans lot costs, planning costs, design costs,etc.) is probably around $100K per unit. I had land division/planning costs.And I was required to install fire sprinklers in the ADUs given their distance from the street (over 150′) which was a substantial cost. |
I live in the red cottage in front of the ADU, it is used for short term rental and my college bound son uses it in between the academic calendar. In the future it will be my retirement home and I will rent out the red cottage.
Type of ADU | New construction studio apartment over garage |
Architect/Designer | Emily ReFi Waterleaf Architects |
General Contractor | I was the general |
Heating System | ductless minisplit |
When did you start the design work? | 10/2012 |
When did you submit the plans to the City? | 1/2013 |
When did you start construction | 2/2013 |
When did you get your certificate of occupancy? | 8/2013 |
Total Square Footage | 400 |
Total Cost | $85K |
Cost/Square Foot | $212 |
Sweat Equity estimate | $15K |
Other special project costs | Putting a french drain along the side of the red cottage at the same time to waterproof the basement. This was the same trench used for plumbing/water lines to the ADU ($8k)New driveway to replace the driveway that was destroyed by the heavy equipment ($6k) |
The scale of the Studio to the the red cottage and garden, it does not overpower the lot or overshadow my neighbors yard. I also like large shower with the rock floor that has no curb.
I like the pine ceiling, it could’ve been just sheetrocked, it adds texture and warmth with the vaulted ceiling. I also like the privacy of the space from the other home and the back patio that looks on to the garden.
I would of liked to put in heated floors on the concrete- but it came off the list because of expense. The concrete is very easy maintenance- you just need to wear slippers.
I would of done it two years earlier!
Since my background is design/build, I understand the process and now help many of my clients with their homes or find them a home with ADU potential. I started a blog – downsize my space during the recession since many of my clients were looking for a simpler lifestyle.
The driveway and landscaping needs to be part of the BIG picture, think big scale of how the ADU sites on the site and will impact your neighbors. Be sure to figure architects costs after when they hand you the plans, there are site visits and changes that will occur.
Working out shared sewer separation, be sure to have survey and engineer and architect all communicating to each other.
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