A one-stop source about accessory dwelling units, multigenerational homes, laneway houses, ADUs, granny flats, in-law units…
1) Marenda Chamberlin and Heidi Lohman
2) Stewart and Lisa Hulick
3) Brian Zoeller
4) Barbara Gundle
5) Elaine Miller
6) Jaime Arb Haessig and Paul Haessig
7) Nancy Yates
8) Patrick Kernan and Lisa Florentino
9) Susan Eliot
10) Armstrong Family
11) Richard and Jacqueline Wallace
*Please note that on the map page of the ADU Tour packet, in the upper left-hand corner list of ADUs, the “#5” was not listed. Therefore, every ADU listed in that legend after the 5th ADU is shifted by one ADU site number (ie ADU #11 is listed as “12”).
Accessory Short Term Rental
Type of ADU | Detached, new construction |
Architect/Designer | Dan Lajoie with Departure Design, http://www.departure-design.com |
General Contractor | Holly Huntley, http://www.environspdx.com |
Heating System | Radiant wall mounted units |
When did you start the design work? | 10/2013 |
When did you submit the plans to the City? | 2/2014 |
When did you start construction | 3/2014 |
When did you get your certificate of occupancy? | 7/2015 |
Total Square Footage | 620 |
Total Cost (including sweat equity) | $140K |
Cost/Square Foot | $226 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $25K |
Other special project costs |
Bringing in a new service through PGE ($3K) |
We love the natural light and openness of the space. We were going for a more modern/industrial feel and we’re really happy that we were able to achieve that. We’re also really proud of all the reclaimed wood and materials that were used along the way – especially the custom made sliding door in the loft.
The heating system. We were apprehensive about using a ductless mini-split because of its size and presence in the living are, but now we wish we gone that route.
Advanced framing, thicker wall cavity for more insulation, lots of reclaimed materials, windows and doors with low U values, low VOC paint and sealers, low flush toilet, air sealing, dense pack insulation, insulated foundation.
We did much of the interior work ourselves and we completely underestimated the amount of time and material that goes into each section of the ADU. For example, when we were installing the loft flooring using reclaimed tongue and groove car decking, we did not factor in the cost of all the materials needed to complete the project – additional blades for the planer, epoxy to fill the holes, renting a sander and all the sandpaper that goes into it, drill bits, 3 coats of sealer, etc. Those $20 dollar hardware store runs really added up.
We were also surprised at the amount of decisions we had to make! Things that we had never thought about until it was time to install…the color of the cement flooring, color of the gutters, faceplates, the look of the screws that would be visible, the hardware for the kitchen…the list goes on and on.
Be patient with the process and know that everything can be fixed. We had our fair share of expectations that weren’t met and miscommunications, but having open communication and patience really helped us through the process.
New construction can tear up more of your yard than expected, so including final landscaping costs into your budget it a must – something that we learned after the fact.
If you’re using reclaimed materials or doing work on your own, it’s so important to stay on top of the prep work because things often need more work than anticipated.
The city was VERY specific about the insulation requirements, window sizes and the look/color of our address.
The plan is to initially use the ADU as an accessory short term rental. If this proves to be too much of a hassle or is not financially viable, we will switch to using it as a traditional rental.
Type of ADU | Detached, new construction |
Architect/Designer | Willie Dean, http://www.groundupdesignworks.com |
General Contractor | Self general contracted |
Heating System | Ductless mini-split |
When did you start the design work? | 5/2014 |
When did you submit the plans to the City? | 2/2015 |
When did you start construction | 4/2015 |
When did you get your certificate of occupancy? | 10/2015 |
Total Square Footage | 600 |
Total Cost (including sweat equity) | $130K |
Cost/Square Foot | $217 |
Sweat Equity estimate (part of the “Total Cost” listed above) | All design, management and much of the labor ($10K) |
Other special project costs | Tearing down old garage ($2K) |
I love the flow with the existing house. When on the second floor you see down the driveway, into the street and not into the back of the house. Love the exposed beams in the kitchen. Great light in the house and no direct windows into any neighbors house.
That 3 windows facing my house aren’t higher as there will be a little view into each house through these windows.
High R rating for insulation.
I have found the process to be very smooth.
Just to do it if you can. And before next July before the fee waiving period ends. Whether its going to be a short term rental or a traditional rental its going to have a great return on Investment and make your existing house mortgage free.
At this point, the owner will either live in the ADU and rent his house out as a short term, furnished rental or he will rent out the ADU for short term furnished or long term rental.
Type of ADU | Detached, garage conversion |
Architect/Designer | Brian D’Agostine, www.istockhouseplans.com |
General Contractor | Self general contracted |
Heating System | Convection based heating unit |
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 | 2/2014 |
When did you get your certificate of occupancy? | 1/2015 |
Total Square Footage | 280 |
Total Cost (including sweat equity) | $70K |
Cost/Square Foot | $250 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $22K |
Other special project costs | Extra time and cost was applied to advanced insulation, ventilation and air sealing techniques and materials ($4k)
Upgrading footings and slab for leveling, moisture, insulation and earthquake proofing ($5K) Installing a soffit/ridge vent roofing system ($2k) |
Certifications |
Brought to you by Energy Trust of Oregon, EPS™ is |
It has a natural, quiet and open feel for a tiny house where much of the effort was placed behind the walls.
Loft could have been lowered by 1/2 foot to provide more space above the living area and the space heater should have been lowered.
Being the GC was a welcome learning process in so many ways, but it is not for everyone. I should have had a better time frame in mind and realistic budget to accompany my goals. I did appreciate Energy Trust of Oregon and they should be consulted for construction advice and potential incentives.
Know what you want the ADU to be and do for you and the property and build it for that purpose.
I decided not to go through the process of putting on a second story and seeking variance(s) which kept my interaction with BDS at a relative minimum.
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I will use for AirB&B to start. Other future options could be long term rental, live in it myself and rent out my big house, or sell the whole kit and kaboodle.
(Organizer’s note: This ADU is located in Irvington, and was subject to additional Irvington Historic District design overlay considerations).
Type of ADU | Garage conversion with 2nd story addition |
Architect/Designer | Jack Barnes, http://www.jackbarnesarchitect.com |
General Contractor | Birdsmouth Construction Co., http://www.birdsmouthconstruction.com |
Heating System | ductless mini-split |
When did you start the design work? | 10/2014 |
When did you submit the plans to the City? | 3/2015 |
When did you start construction | 7/2015 |
When did you get your certificate of occupancy? | 11/2015 |
Total Square Footage | 650 |
Total Cost (including sweat equity) | $160K |
Cost/Square Foot | $246 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $2000 |
Other special project costs | Connecting the new sewer to my big house, which wasn’t technically part of the ADU, but was related to it. ($5K) |
I love the way the second floor has so much light and air circulation and the view on all sides is green growing plants!
Don’t know yet…but do wish the spiral staircase didn’t take up so much room!
Lots of insulation, mini-split ductless heating system.
Nothing!
The cost.
Start early, talk to friends, look at what others have done before you, use an architect
I did have a non-compliant partyline sewer on my big house, but it was not a huge problem, just added to the total bill. The city conveniently put in a brand new sewer line on NE 11th in May/June of 2015, so it was there when I began work on my ADU, and I hooked up both the main house and the ADU to the new line at the same time.
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Initially, we will use the ADU as a short-term rental property and learn just how much work that involves. In the mid to long term my brother, Robert, who suffered a head injury long ago and currently lives in Hawaii, will live in the little house. It is close enough for us to watch over him and give him some community but at the same time offers him his own space and privacy.
Certified Earth Advantage
Type of ADU | Detached, new construction |
Architect/Designer | Polymath Studio, http://polymathstudio.com/about/ |
General Contractor | Design Build Portland, http://www.designbuildportland.com |
Heating System | electric wall heat, radiant floor in bathroom and plans to add gas stove this winter. |
When did you start the design work? | 2/2014 |
When did you submit the plans to the City? | 9/2014 |
When did you start construction | 11/2014 |
When did you get your certificate of occupancy? | 9/2015 |
Total Square Footage | 550 |
Total Cost (including sweat equity) | $165K |
Cost/Square Foot | $300 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $2500 |
Other special project costs | The water line between main house and street disturbed by water pressure to ADU. $2,500
Tore down old garage and pulled up foundation: $2,500 Using reclaimed lumber on staircase turned out to be a problem with lots of overages: $5K |
Certifications |
Earth Advantage Gold |
Exposed ceiling wood, staircase, exterior large overhang that shades (and keeps dry) south facing exposure.
Shower is too big making bathroom too small to move around in. Should have put in TV cable as very hard to get wifi from my main house. Should have done more lighting controls/dimmers.
Rest I love.
Ridged insulation on ceiling, super insulation throughout, Energy Star appliances when possible, LW flush toilet, all EE lighting with mix of CFLs and LEDs, minimal heat / cooling requirements so opted to not do ductless heat pump as that would have been oversized for the space. Will add an efficient gas stove soon. It’s also designed for passive solar heating in the winter.
Nothing!
I was shocked at the number of decisions you have to make. Plan for time to research and make these decisions as my contractor did not have the time to focus on this and things came up unexpectedly. I also learned that it can be hard to get your contractor to finish the project!
Be brave, plan to spend more that you think (but you will make it back), and go with it. It will be OK!
Found a long lost septic system right before construction which had to be mitigated. Some issues with on demand gas water heater being hidden under stairs with a kitchen cabinet in front of it that blocks access. Solution is to make cabinet removable. One issue with skylight support and solution was to add supports. Also had an issue once water line was hooked up between ADU and main house. The main line was disturbed but was old, so we ended up having to replace that line (street to house).
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Traditional rental
Type of ADU | Detached, new construction |
Architect/Designer | Propel Design Studio, http://www.propelstudio.com |
General Contractor | Gibson Builders |
Heating System | Radiant floor |
When did you start the design work? | 6/2014 |
When did you submit the plans to the City? | 10/2014 |
When did you start construction | 4/2015 |
When did you get your certificate of occupancy? | 10/2015 |
Total Square Footage | 792 |
Total Cost (including sweat equity) | $170K |
Cost/Square Foot | $215 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $15K |
Other special project costs |
Upgraded water line (3K) Sprinkler system (5K) Utility vault for sprinklers system (5K) |
I believe my favorite thing will be the open layout and the vaulted ceilings.
The utility vault is still hard to get used to aesthetically and spatially.
Insulation, insulation, insulation. Exterior walls have 2″ foam insulation, the roof has 3″ insulation and the walls have standard batt insulation. We are also using a tankless water heater and radiant floor heat.
It was a certainly a larger and longer process than I expected.
Build a comprehensive budget well in advance and include an expected 15K overage. Something will come up, it always does. If you get lucky and don’t have any overage then you have a nice savings started to take a long trip to celebrate your completed project.
We had to install a utility vault to hold the water tank for the sprinkler system we had to install due to the distance to the ADU from the street. (Fire Marshall requires sprinkler system or fire lane if the back of the ADU is more than 150 feet from the street.)
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Considering use as short to long term rental, living space for elderly relative and/or care provider.
Type of ADU | Detached, new construction |
Architect/Designer | Self-designed, drafted by Builder’s Design Inc, buildersdesigninc.com |
General Contractor | Cedar Ridge Homes, Troutdale OR |
Heating System | Ductless mini-split, cadets in bedrooms |
When did you start the design work? | 10/2014 |
When did you submit the plans to the City? | 3/2015 |
When did you start construction | 5/2015 |
When did you get your certificate of occupancy? | 10/2015 |
Total Square Footage | 798 |
Total Cost (including sweat equity) | $189K |
Cost/Square Foot | $237 |
Sweat Equity estimate (part of the “Total Cost” listed above) | landscaping- $4K |
Other special project costs | Landscaping in the newly created space between the ADU and main house. ($4000).
plants, rock, structured water, kitchen island ($2,515) |
The ADU mirrors the design of my home in a very complimentary way, tall ceilings, lots of windows, and open kitchen and living areas. I am excited about creative possibilities for landscaping the space between the two buildings which feels like a courtyard.
From the street it looks like a good-sized house.
Construction methods changed since completion of the main house in 2013 resulting in subtle necessary differences in the new ADU building, probably noticeable only on close scrutiny, such as height of the facia and siding assembly.
Also, if I had it to do over again, I probably would have planned more accessibility features.
Dense foam insulation, instant hot water heater, orientation for natural light exposure, lots of windows, ductless heat pump mini-split.
Some lighting LED, No VOC paint and structured water system.
That this was a bigger than anticipated project, which is why I ended up relying on conventional building methods as opposed to sweat equity, with higher costs overall. I learned during this build and one earlier to try your best to remain flexible in addressing issues and necessary changes as they arise. Pay attention to how the space feels as you construct it. For example, a car space could end up better suited as usable people space, with the car space elsewhere, or a kitchen island might need to be scaled back or eliminated. And use any and all nooks and crannies for storage.
An appreciated suggestion had been to build the ADU mindful of how it will fit into the “life” of the property over the long run, so that I wouldn’t lock myself out of future development I might not be thinking about at the moment. Also, build the ADU to the maximum space your property will allow and also the maximum size and amenities your budget will allow. You (probably) only do this once, so be sure you have something you are happy with in the end. And finally, if you like it enough to live there yourself, then you will never have a problem having someone else want to live in your ADU.
Not really. Set back had to be at least 60 feet.
(Organizer’s note- this ADU is actually in front of the main house, which worked without an adjustment because of the unusual depth of the lot.)
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We are living in it.
Type of ADU | Detached, new construction built in place of old garage |
Architect/Designer | Brad Bloom, portlandgardencottages.com |
General Contractor | Self general contracted |
Heating System | Ductless mini-split |
When did you start the design work? | 5/2013 |
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? | 2/2015 |
Total Square Footage | 568 |
Total Cost (including sweat equity) | $108K |
Cost/Square Foot | $190 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $10K |
Other special project costs | A gas line because we really wanted a gas stove |
We are extremely proud of our designer/craftsman Brad Bloom, whose artistic vision gave us a warm, light-filled livable house. The old-growth fir from the deconstruction of the old garage was milled down and used for interior and exterior trim, and for carved sliding panels between the living and dining room.
No covered parking
Ductless mini-split
It was surprisingly easy and very creative.
Be sure to allow enough time to allow for serendipitous inspiration working with salvaged and reused materials, which takes time. But, it was worth it.
Unexpected insulation requirements for vaulted ceiling.
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Primary residence
Type of ADU |
Detached, new construction |
Architect/Designer |
Dennis Myers, http://www.lifespacedesign.com |
General Contractor |
Rob Bilyeu, http://www.bilyeuconstruction.com |
Heating System |
Ductless mini-split |
When did you start the design work? |
11/2014 |
When did you submit the plans to the City? |
12/2014 |
When did you start construction |
2/2015 |
When did you get your certificate of occupancy? |
6/2015 |
Total Square Footage |
600 |
Total Cost (including sweat equity) |
$115K |
Cost/Square Foot |
$192 |
Sweat Equity estimate (part of the “Total Cost” listed above) |
$2K |
Other special project costs | None |
I love the natural light that floods every room. I have 23 windows and the building orients to the south.
No garage
None
How quickly an entire free-standing house can be built from the ground up.
Find a lot that allows plenty of separation from the main house if you plan to live in the ADU and rent the main house.
The elder Armstrongs will live there for 4-6 months during the summers when they move to Portland to escape the heat of Dallas, TX. The younger Armstrong will rent it out the rest of the year.
Type of ADU | Detached, new construction |
Architect/Designer | Strongwork Architecture, LLC, http://www.strongworkarchitecture.com |
General Contractor | Self general contracted |
Heating System | Ductless mini-split |
When did you start the design work? | 12/2013 |
When did you submit the plans to the City? | 2/2015 |
When did you start construction | 4/2015 |
When did you get your certificate of occupancy? | 10/2015 |
Total Square Footage | 546 |
Total Cost (including sweat equity) | $111K |
Cost/Square Foot | $201 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $30K |
Other special project costs | Structural Insulated Panels “SIPs” for the floor and roof ($8k) |
High performance building envelope, vaulted ceilings, exposed beams
Well there’s a lot of little things that I wish we had done slightly different. When you are playing the general contractor role for the first time and are dialed in to every single detail of the construction process, it’s hard not to see and worry about all the little things that could be improved. But we’ll chalk it up as practice and try to do a little better on the next one. Overall I think it is going to be a very successful and attractive little house and it’s going to be perfect for my parents. If I had to pick one thing to do over it would be to go ahead and apply for the Land Use Adjustment to build into the setback to gain a few feet of interior width on the interior of the ADU and potentially avoid the Building Code Appeal and fire wall.
Super insulated SIP floor and roof, R-5 continuous exterior insulation at the walls. We installed an Energy Recovery Ventilator to bring fresh air into the ADU without wasting conditioned air.
We have a renewed appreciation for general contractors. Even for a 546 sf structure there is an extraordinary amount of decisions to be made and parts and pieces to be coordinated. It’s like a 5:1 brain power to square footage ratio.
(1) If you are going to design and build it yourself, you must go the extra mile and figure out all the details. It’s easy to think, “Oh I’m building it myself so I can figure that thing out later.” But it doesn’t work like that. You will save yourself a lot of grief by either (a) diving deep into the details and making sure everything is dialed in and makes sense, or (b) keeping the design extremely simple.
(2) If you think you might need to apply for the Land Use Adjustment to get the design you want….do it. If you do, 5 or 10 years from now you won’t remember the $2000 and 60 day wait for the Adjustment, but if you don’t get it, you’ll remember that you wished you had.
Due to the conflict between the required eave depth and the proximity to the primary house we had to get a Building Code Appeal and create a 1 hour fire rated separated wall and eave on the side of the ADU facing the house.
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Initially a short term rental minimum 2-3 days at a time to see how we like it.
Type of ADU |
Second-story ADU addition over a portion of our house that was previously one story |
Architect/Designer |
Doug Minarik, http://www.minarikarch.com |
General Contractor |
RS Wallace Construction Co., http://www.rswallace.com |
Heating System |
Ductless mini-split, cadet in bathroom |
When did you start the design work? |
9/2014 |
When did you submit the plans to the City? |
3/2015 |
When did you start construction |
3/2015 |
When did you get your certificate of occupancy? |
11/2015 |
Total Square Footage |
489 |
Total Cost (including sweat equity) |
$140K |
Cost/Square Foot |
$286 |
Sweat Equity estimate (part of the “Total Cost” listed above) |
$15K |
Other special project costs |
Because the quantity of plumbing fixture units in our house combined with The existing foundation under the back eight feet of our existing house was poor quality we also had the added cost to shore up the house, remove that portion of the foundation, pour a new foundation and then set the house back down. ($15K) We decided to build an exterior stair of metal and concrete instead of losing interior space for an inside stair. ($10K) |
The high vaulted ceiling. The large high quality windows and all the natural light
Next time I would run the support posts for the exterior stair landing straight down to new footings instead of steel braces back to the house. I was trying too hard to save yard space but it made the engineering and the construction more difficult and expensive.
Spray foam and blow in insulation well above code. Mini-split HVAC system. Extremely durable finishes / windows / stair.
No major surprises. I think in the future I would use open web floor trusses for this of project instead of a center beam and posts to ease installation of plumbing and heating systems.
Putting the stairs outside is a good option if you have a small lot or do not want to lose much space in your existing garden / yard. But if you can put the stair inside your house that will save you money.
Spend the extra time with your Architect to plan your soundproofing and all aspects of your design.
Not really.
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