A one-stop source about accessory dwelling units, multigenerational homes, laneway houses, ADUs, granny flats, in-law units…
These were the ADUs that were featured on the September, 2016 ADU Tour page. Read about the ADU Tour, and view ADUs featured on previous ADU Tours here.
1) Ben Brizuela
2) Stephanie Macdonald
3) Justin & Sarah Schumacher
4) Rambo Halpern
5) Kendra and Victor Duong
6) Nancy Hiss and Dan Berkman
7) Valerie Bryan
8) Chris Botero / Stumptown Construction Group
9) Chris Botero / Stumptown Construction Group
10) Roz and Bonnie Roseman
11) Natalie and Justin Strom
12) Eli and Noelle Spevak
I was going through a divorce and I was looking for a way to afford my mortgage on my own. It was during the recession and there wasn’t much work for a general contractor. As a builder, this was an accessible path to added income. I had planned on moving into it and renting out my primary residence after my kids left home.
Type of ADU | Detached, new construction |
Current Use | Short term rental |
Architect/Designer | Terah Beth Varga, thejackandmare.com |
General Contractor | Fine Hand LLC |
Heating System | ductless minisplit |
When did you start the design work? | 3/2012 |
When did you submit the plans to the City? | 6/2012 |
When did you start construction | 7/2012 |
When did you get your certificate of occupancy? | 4/2014 |
Total Square Footage | 778 |
Total Cost (including sweat equity) | $150K |
Cost/Square Foot | $192 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $60K |
Other special project costs |
I kept the slab from old garage and had to cut and patch it, adding additional labor ($5K). It would have been cheaper to tear it out and re-pour. I also included three separate electrical meters, which changed the location of the service drop and allowed me to run the power to the primary residence underground. ($12K) |
Short term rental, guest house for family and friends, long term rental and primary residence
First I developed a budget, then I hired a designer who I knew from friends. I also secured some private financing. I knew I would be doing the building so I didn’t need to look for other help than a designer.
The designer and I went to the BDS office twice. It was pretty easy.
I estimate it will take 8-10 years of rental income to make back the $150K it cost to build.
Living roof (to be installed)
My favorite parts are the back deck and the natural light.
The back deck with its view and relationship to the trees is wonderful but I am most proud that I finished it.
If I were to do it again, I would have maxed out the square footage and added more area to the bedrooms.
I would have accounted for my living expenses while building the ADU. I put so much sweat equity in and didn’t account for how much lost wages I would lack.
I surprised myself with my ability to compete such a big project from start to finish on my own.
Expect to spend more than you think. Value your time and cost analyze when to use subcontractors and when to do the work yourself.
When looking to purchase a rental property, I looked for a property with good potential for an ADU to increase my profit margin. The 1920’s house I purchased had a new garage (built in 2008) with high ceilings that seemed perfect for an ADU.
I financed most of the construction cost with the purchase of the home and will pay off the remaining cost in 2 years.
Type of ADU | Garage conversion |
Current Use | Rental |
Architect/Designer | Jacob Chavez , jchavezdesign.com |
General Contractor | Jacob Chavez , jchavezdesign.com |
Heating System | Ductless mini-split |
When did you start the design work? | 11/2015 |
When did you submit the plans to the City? | 1/2016 |
When did you start construction | 1/2016 |
When did you get your certificate of occupancy? | 6/2016 |
Total Square Footage | 540 |
Total Cost (including sweat equity) | $120K |
Cost/Square Foot | $220 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $1.5K |
Other special project costs | None |
It may be used as a short-term rental or primary residence in the future.
Attended ADU class, ADU tour and met with two designers. I chose to work with a Design Builder.
It originally looked like we would need full walls on the second floor rather than a loft but it turned out that we had enough ceiling height to have it remain open.
With a rental income of $1400, the ADU will pay for itself in seven years. After which time I will make rental income free and clear and will have fully paid off the cost of construction. It will also provide a great option for living space for myself or a family member in the future.
Blow in insulation, upgraded to 2×6 studs for more insulation
I like the open, lofted floor plan that feels spacious. The design is functional, attractive, bright and modern. I’m pleased with the windows we selected as well as all of the wood we incorporated throughout.
The reclaimed cedar wall defines and adds interest to the nook under the loft. I’m thrilled with the custom-built steel railing- it’s beautiful, compact and functional.
I wish we had found ways to incorporate more storage into the unit.
I would have required a bid rather than a “budget”. This project was budgeted for 70k and it came in at almost double that.
Even though I had a general contractor, this was a very time-consuming process. From researching to selecting products and finishes, I spent many hours every week on the project.
Make sure you have a clear, detailed list of expectations and an agreed-upon structure for communication that includes timelines for decisions, etc.
We had an existing garage that was in disrepair and when we discussed repairing it we started to think that we could find a better use for the space. With 2 adults/2 kids in our existing 1400 sq. ft house we don’t have a spare bedroom for friends & family to visit, and we thought it would be nice to have a cottage in the backyard for such occasions. Being able to rent the ADU out when we’re not using it ourselves made it a financially viable option.
Type of ADU | Detached, new construction |
Current Use | Short term rental, friends & family visits |
Architect/Designer | Jack Barnes, jackbarnesarchitect.com |
General Contractor | Harding Construction, hardingconst.com |
Heating System | Ductless minisplit |
When did you start the design work? | 4/2014 |
When did you submit the plans to the City? | 4/2015 |
When did you start construction | 6/2015 |
When did you get your certificate of occupancy? | 5/2016 |
Total Square Footage | 650 and 100 sq ft bike garage |
Total Cost (including sweat equity) | $285k |
Cost/Square Foot | $380 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $5k |
Other special project costs | Adjustment ($2k) Cesspool Removal (~$1k?) Deconstruction of old garage ($1400) |
Certification & Energy Scores | Earth Advantage Platinum and EPS |
Primary residence once the kids grow up
Took Kol’s ADU class & attended ADU tour. We spoke to several architects and ultimately chose Jack, who had designed one of the ADUs we saw on the ADU tour. The builder we selected, Harding Construction, had also built one of the ADUs that we saw on the tour that we particularly liked.
Requested adjustment to build close to property line. Process took extra time and money ($2k), but Jack (architect) handled interactions with BDS and all went smoothly. City required us to locate underground cess pool (which we found and removed).
Taking into account the full cost of the project, short-term rental income, additional monthly expenses, property tax increase, income tax on rental income, and opportunity cost (5%), we estimate the ROI to be 11 years.
dense pack cellulose insulation, air sealing
Since the ADU consumed a major portion of our back yard, we wanted to build a space that felt like an extension of the yard. We added a 3-section 10-ft wide folding glass door to allow the ADU to open completely up to the outside. On a warm night with the panels open and the curtains billowing it feels like a tropical vacation right in our backyard.
Three features that we’re really proud of are:
1) The railing– we collected a bunch of old bike parts and Alameda Metal Works did an amazing job incorporated them into the railing.
2) The light fixtures– we built a few of the light fixtures ourselves out of pipes with a “steam punk” style.
3) The stairs– the builders did an amazing job on the stairs, and we painted book spines on the risers to add some character.
The downstairs bedroom doesn’t get much natural light, due to building right next to the fence on the property line. However, we knew this during design, and made the trade-off deliberately to retain some of our yard space.
We are so happy with how the ADU turned out and there isn’t much we would do differently if we did it again. However, we would go in more mentally prepared for how long the project would take, as it took about twice as long (2 years) than we thought it would.
Labor is expensive! Some of the most expensive parts of our project were things that are relatively easy, but just take a lot of time (such as painting). If you have the time to do these things yourself, you can save a bundle!
Be prepared to make lots and lots of decisions trading off design features and quality against cost. It’s almost definitely going to cost way more than you think at the outset. We went into the process thinking that we could build the ADU we wanted for $150k, and we spent almost twice that. That said, we are very happy that we chose to spend more to build something unique with high quality that will last a long time.
I thought it was a unique opportunity that Portland allows ADUs and I wanted to take advantage of it. I wanted a separate space for my son when he hits his teens, a possible rental income in the meantime and possibly a spot for my parents if/when they need more assistance.
Read the blog post on AccessoryDwellings.org about this ADU.
Type of ADU | ADU above a garage |
Current Use | Rental |
Architect/Designer | self-designed |
General Contractor | Red Rock Construction LLC |
Heating System | ductless mini-split and cadet |
When did you start the design work? | 2/2008 |
When did you submit the plans to the City? | 4/2008 |
When did you start construction | 2/2009 |
When did you get your certificate of occupancy? | 12/2009 |
Total Square Footage | 799 sq ft ADU and 936 sq ft garage |
Total Cost (including sweat equity) | $156K |
Cost/Square Foot | $89 (including costs of garage in this calculation) |
Sweat Equity estimate (part of the “Total Cost” listed above) | About $20K. The contractor took care of most of the work but I did spend a lot of time in the design process. |
Other special project costs | Permit fees for the ADU were around $15K at that time. Also we went with an all wood window package which added significantly to the cost. |
We may consider short-term furnished rental, additional studio space for ourselves and possible living space for our parents in the future.
Found base plans that I liked online, multiple discussions with my contractor, drafter, engineer etc…
It was a few years ago but I do recall it taking a long time and we had to make multiple revisions. The permit was quite expensive as well.
It has been outstanding. Has always rented very easily and rent has increased every year. More than pays for the cost of building it.
Blown in insulation, dual-flush toilets, on-demand water heater, mini-split heating/cooling
I like that the aesthetic blends well with the house. I also like that it provides privacy for us as well as the tenants. The design is a nice open floor plan but also provides a good size private bedroom.
I like the wood windows and the exterior appearance including the all-wood corbels and craftsman architecture.
It takes up a lot of space so our back yard is smaller than we would like. Also the ADU does not have any outdoor space dedicated to it.
I might do a two-bedroom. I would also design it with some small private outdoor space, patio or decks.
The length and complexity of the build process, both in dealing with the city and managing the sub-contractors.
Make sure to do proper sound-deadening between the unit and the garage. If you are planning on renting, spend the extra money to have separate utilities to the ADU, it will pay off in the long run.
We purchased this property as an investment 10 years before we started the ADU project. We wanted to buy another investment property but with houses prices and availability in recent years, we saw that was going to be challenging. Since Portland allows an ADU on a rental property, we decided to increase our investment on our existing property.
Read the blog post on AccessoryDwellings.org about this ADU.
Type of ADU | Detached, new construction |
Current Use | Rental |
Architect/Designer | Kendra Carson Duong, http://www.duongarch.com |
General Contractor | John Gray Design, LLC, http://www.johngraydesign.com |
Heating System | Cadet Apex |
When did you start the design work? | 11/2014 |
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? | 9/2015 |
Total Square Footage | 400 |
Total Cost (including sweat equity) | $112K |
Cost/Square Foot | $281 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $8000 |
Other special project costs |
None |
Rental for now, possibly short term rental in the future.
Looked at a couple plan sets by other architects, got a HELOC.
The city would not allow a storage loft over the bathroom.
We got a plan check comment about our windows, because we included transom windows over windows that matched the window size on the main house. We had to justify the transom windows by explaining that there are taller ceilings in the ADU than in the main house, so it needed taller windows to be proportional.
This is a long term investment, payback about 9 years.
Green features include a dual flush toilet, fully insulated slab, fully insulated attic trusses (R-38 at shallowest area, R-50 or more in deepest area), passive strategy cooling, window u-value =0.25, intermediate framing, and a tankless water heater.
The amount and distribution of windows, interior accent paint color, interior transom window between the bath and living areas, tall ceiling, large porch, tiled deck-mounted tub.
That the tenant loves living there.
Cracks in the concrete floor between control joints, tenant says heaters can be loud, location of electrical panel.
Swing double doors out instead of in. Perhaps a flat ceiling at the porch. Extend overhang over south-facing windows. More operable transom windows.
Sub-contractors building something other than what was designed.
Allow yourself enough time to develop the design.
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I needed to move my parents from Maryland to Portland. They need daily living assistance. A separate living space, in very close proximity to the primary residence provides them a sense of independence with quick and loving support.
Type of ADU | Detached, new construction |
Current Use | Residence for Nancy Hiss’ parents – Jeanne Hiss (age 88) & Warren Hiss (age 91). |
Architect/Designer | Nancy Hiss |
General Contractor | Mike Anderson, Creative Design & Construction LLC |
Heating System | ducted heat pump |
When did you start the design work? | 9/2014 |
When did you submit the plans to the City? | 1/2015 |
When did you start construction | 3/2015 |
When did you get your certificate of occupancy? | 7/2015 |
Total Square Footage | 731 |
Total Cost (including sweat equity) | $160K |
Cost/Square Foot | $218 |
Sweat Equity estimate (part of the “Total Cost” listed above) | Sweat equity includes design services and coordination with The City – estimated value $5K |
Other special project costs |
None |
aging in place rental unit, and eventually primary residence for Nancy Hiss & Dan Berkman
Reviewed the ADU code and design guidelines. Had a preliminary meeting with the city’s planning department – essential. Deeply researched products and materials. Researched how my parents live. Relied on prior knowledge of compact living structures and ideas from The Not So Big House books.
Approval of rain garden through the County took extra time.
Creating code compliant (sufficient head-room) for the stair took time.
The City was actually very helpful with the stair design.
The initial cost was high, however, the operating costs make it a very economical alternative to an assisted-living facility.
1.) rain garden for on-site storm water management,
2.) durable materials – Hardiplank siding, ceramic tile, concrete decking.
3.) LED lighting
4.) Good cross ventilation including operable skylights.
5.) Energy efficient appliances
It actually works for my parents. They are comfortable and they love it.
Didn’t put loft ceiling fan in.
Loft ceiling fan.
How much we like it, how well it works.
Design from the inside out.
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I decided to tear down my garage and build an ADU in it’s place for several reasons—
Type of ADU | Detached, new construction |
Current Use | Short Term Rental and guest house for family & friends |
Architect/Designer | Mitch Snyder, msnyderarch.com |
General Contractor | self general contracted |
Heating System | ductless minisplit + heated bathroom floor |
When did you start the design work? | 1/2015 |
When did you submit the plans to the City? | spring, 2015 |
When did you start construction | 12/2015 |
When did you get your certificate of occupancy? | 8/2016 |
Total Square Footage | 687 |
Total Cost (including sweat equity) | $160K |
Cost/Square Foot | 232 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $25K |
Other special project costs |
garage/deck tear down ($1k) |
short term rental + long term rental + guest house for family and friends
I did all the many things one can do to prepare for building an ADU in Portland—took Kol’s ADU class, read up on other’s who had built ADU’s, attended ADU tours, explored the various ways to finance the project/got my financial ducks in order, interviewed several architects, etc. However, I’ve come to think the best preparation for building an ADU is the same as for preparing for any other big endeavour in life—realize that if something can go wrong, it will. The more you’re ready for this fact, the smoother you’ll sail through the process.
We anticipated the permit process would take approximately 3 months. It ended up taking nearly twice that due to an appeal my architect had to submit regarding a new requirement to have fireproofing and retrofitting if less than 7 feet between ADU and existing house. And then there was the absurd tree code requirements…
If all goes as planned ( via short term rental ) I foresee being able to recoup the monies invested in building the ADU over the next 5 years. At that point, the plan is to move out of my house and on to other endeavors and rent both the house and the ADU out on long term basis…
custom made eco-friendly kitchen cabinets , dual flush toilet, LED recessed can lighting
Time will tell as we’re still in the finishing stages, but I’m predicting that I will be most happy having a sauna built into the ADU, as well as an open modern aesthetic throughout the interior.
I’m most proud of: the sauna ( Finlandia Sauna kit ), the architecture ( which I have my architect to thank. though it was indeed a collaboration. we pushed for it to be as modern as possible without having to get a variance from the city… ), the beveled cedar siding in the recessed areas ( which will require more ongoing maintenance than if we had simply installed all hardi-plank ), the exterior body color ( that it took me forever to decide upon ) combined with the color of the aluminum clad windows ( Marvin “Cadet Grey” ), the exterior recessed can lighting ( and the motion sensor that turns on the entry portion of it at nightfall automatically ), the while oak floors ( Domino Hardwood Floors ), the kitchen appliances ( Eastbank Appliances ) and the modern fixtures and furnishings.
I’m least happy with not having more of an overhang in the entry which the city wouldn’t let us have because it would have been within the 5 foot setback. One of the many ridiculous wet blanket rules the city has conjured up to supposedly protect it’s citizens…
Though I had a stellar architect to work with and would hire him again in a flash, as well as highly recommend him, I would perhaps entertain the idea of hiring a design build firm or at the very least bring on the builder at the same time as the architect so as to have everyone on the same page from the start of the whole process. Having not done so proved inefficient to say the least!
The most surprising thing I learned during the design/build process is how many seemingly endless decisions there are to be made, how time consuming those decisions can be and how interrelated they are to each other.
Know that new construction takes you on a real roller coaster of a ride—be sure to plan for 2-week’s worth of vacation during the process to give yourself a chance to totally unplug from all the noise both externally and internally!
This house was classic and beautiful. It needed a few touches here and there, but nothing major. The issue was the price. I couldn’t afford to purchase it and rent out just the house. Adding the ADU allowed me to buy the property, rent two units and have it make financial sense.
Type of ADU | Basement ADU conversion |
Current Use | Long-term rental |
Architect/Designer | Self-designed |
General Contractor | Self general contracted / Stumptown Construction Group |
Heating System | radiant hydronic via electric water heater |
When did you start the design work? | 3/2015 |
When did you submit the plans to the City? | 4/2015 |
When did you start construction | 4/2015 |
When did you get your certificate of occupancy? | 1/2016 |
Total Square Footage | 799 |
Total Cost (including sweat equity) | $100K |
Cost/Square Foot | $125 |
Sweat Equity estimate (part of the “Total Cost” listed above) | Self-general contracting, some of my own labor and work from my crew probably saved me $50K. |
Other special project costs | Moving mechanicals, but this would be included in a comparable basement conversion. |
Long-term Rental
Nothing, really.
The ADU addition required up-sizing the water meter. Instead, I found it was more cost effective to add a second water service specifically for the ADU. Also, placement of the back-flow prevention devices in the floor posed a challenge considering I did not want them visible in the floor of any room.
It cost me about 100K to add the ADU. It brings in $2000/month. I could borrow the 100K, pay 6% interest on it ($1000/month) and the asset will more than cover the cost to build the asset.
In-floor radiant heat
The open concept living area/layout and the fact that I was able to fit 2 bedrooms and 2 bathrooms, the contemporary design/finishes, hydronic radiant floor heat with acid-etched concrete floors.
Contemporary design, in-floor heat, transom window above the front door.
Ceiling height. It turned out at roughly 7’4″, but I would like it to be more.
I would have dug down in the basement to create more ceiling height considering I had already pulled out the slab.
It always takes longer and costs more than you think.
Pay attention to head height, window size (light), allow for a longer time-line and larger budget than you expect.
Organizer’s note: This project is still under construction. So, use caution if you visit the interior of this ADU. It’s also part of a fascinating larger development project on the same lot. Here are three 4-7 minute audio segments in which the owner/developer discusses various aspects of the project.
The ADU addition is a way of creating another income source in a residential zone that wont allow for more density. It also allows for the neighborhood feel to remain while making a project like this one financially viable. My purpose for building the ADU was a financial decision. The additional income from the ADU coupled with the house made paying the high purchase price and high renovation costs actually work. As well, this particular parcel is dividable, so I can partition the lot and build another house with ADU behind the current house.
Type of ADU | Basement ADU added by lifting existing house |
Current Use | Will be used as a long-term rental. |
Architect/Designer | Self-designed |
General Contractor | Self general contracted / Stumptown Construction Group |
Heating System | radiant hydronic via electric water heater |
When did you start the design work? | 1/2016 |
When did you submit the plans to the City? | 2/2016 |
When did you start construction | 2/2016 |
When did you get your certificate of occupancy? | 10/2016 |
Total Square Footage | 610 |
Total Cost (including sweat equity) | $150K |
Cost/Square Foot | $245 |
Sweat Equity estimate (part of the “Total Cost” listed above) | I am the general contractor and have my crew doing some of the work. I would say the combination will save me at least $50K over hiring out the job. |
Other special project costs | Foundation replacement ($30K)
street tree replacement ($5K) hydronic heat system ($8K) |
Long-term rental.
I have built 4 ADUs prior to this one, so there wasn’t much preparation on this one.
Not on this project. I was actually issued this permit over the counter where they normally take them in for review. I think I just lucked out on this one.
I base it on my cost of funds and the income it produces. Basically, I could borrow the money to build the ADU, 150K, and pay 6% interest on that money which would be $750/month. I think this unit will bring in about $1500/month, so the asset creates twice the income as the debt service required to create the asset.
Hydronic floor heat
Acid-etched, heated concrete floors, large windows for lots of light, high ceilings (9 foot).
The ceiling height. Adding an ADU to a basement has an inherent issue of feeling like a basement. This one will not feel like a basement at all.
Square footage. I would like to have a larger living space, but I was bound by the footprint of the existing house. Also, stacking units on top of each other is not ideal. Extra efforts to sound insulate will help.
I would have started the design process immediately after purchasing the house. As it was, I spent about 6 weeks gutting the house before doing anything with design. It would have saved a bit of time.
I have done this several times, but I would say the surprises are always the same two things…it costs more than you think and takes longer than you think.
Be generous with your budget and with your timeline. Remember, once it is done, it will create income forever!
We wanted three generations to live together and have privacy. After searching unsuccessfully for a duplex, we bought a home and built on an additional living area that met everyone’s needs.
Type of ADU | Attached addition ADU |
Current Use | Multi generational, family living |
Architect/Designer | Jeff Bromwell, jeff@urbandesignbuildcompany.com |
General Contractor | Urban Design Build |
Heating System | Gas fireplace and 2 Comfort Cove radiant wall heaters (electric) |
When did you start the design work? | 1/2012 |
When did you submit the plans to the City? | 3/2012 |
When did you start construction | 4/2012 |
When did you get your certificate of occupancy? | 10/2012 (ADU conversion in 6/13) |
Total Square Footage | 660 |
Total Cost (including sweat equity) | $167K |
Cost/Square Foot | 253 |
Sweat Equity estimate (part of the “Total Cost” listed above) | $0K |
Other special project costs | Personal selections, because it is owner occupied, were higher than they otherwise would have been. For example, more tile than is typical was used in the bathroom. A curbless shower was installed for future mobility issues to ensure our ADU facilitates aging in place. |
Owner occupied, extended family living.
We went to a home show and looked for builders presenting ADU’s and pulled recent ADU permits and drove around looking at them. We then met with a number design builders and selected one.
We initially built an addition with a second kitchen agreement and our contractor went through the FIR (Field Issuance Remodel Program) and later converted the addition to an ADU, with no structural changes. It went pretty smoothly.
Our return on investment is not the point for us. It is about the satisfaction of our three generations living together in such harmony, though it certainly has made our home much more valuable.
Lots of insulation, bamboo flooring, tankless water heater
Roz loves having a great room that keeps all her daily living activities and her guests together and having a fireplace. Being attached to the main house and the rest of the family, but having peace, quiet and privacy is perfect.
Roz especially loves the quality details of her entry- the stoop matches the main house. She enjoys the beautiful wooden door that reflects the styling of the original design of our house every time she comes home.
Every design decision made solely to save money resulted in minor regret. For example, the kitchen would have been better left as originally designed as an L, rather than all on one wall. Another example, is having skipped including a hand held shower in addition to the overhead.
Had we understood we would need a separate water heater for the unit, we would have avoided an exterior unit.
The dramatic evolution from the initial thought of a 2-story, detached unit, to a one level attached unit with a connecting passageway, was really a surprise, and the result is perfect for us!
The most important design factor when building an attached unit is to make sure it ties in as seamlessly as possible with the original home. Remember to include sound proofing in all common walls.
Being on a corner lot, our old and dilapidated garage always seemed like the perfect site to build something entirely more useful. We first learned about ADUs through a contractor friend who pointed out the temporary waiver of certain building fees for ADUs in the City of Portland. We decided to build an ADU to maximize the potential of the lot, for use as a rental, with the idea that the two of us could live there after the kids are grown up and gone.
EPS certification (score:36)
Type of ADU |
Detached new construction |
Current Use | Long-term rental |
Architect/Designer |
Carrie McIntyre |
General Contractor |
Oreste Construction |
Heating System |
ductless minisplit |
When did you start the design work? |
6/2014 |
When did you submit the plans to the City? |
4/2015 |
When did you start construction |
7/2015 |
When did you get your certificate of occupancy? |
4/2016 |
Total Square Footage |
720 |
Total Cost (including sweat equity) |
$200K |
Cost/Square Foot |
$277 |
Sweat Equity estimate (part of the “Total Cost” listed above) |
$0 |
Other special project costs | None |
Energy Scores | EPS |
Possible short-term rental, friends/family, retirement home for owners
Along with our architect, we attended Kol’s ADU class. We used Kol’s blog to answer a lot of questions and as a starting point for further research. We met with contractors and specialists in energy efficient building practices.
No significant issues.
We essentially have two fully-functioning houses on our lot, and it’s likely that our property value went up by at least the cost of building the ADU. Before deducting income tax or property tax (still an unknown), we will pay our ADU off in about 8-9 years if we keep renting it out long-term.
spray foam insulation in ceiling; blown-in in walls; cork flooring
Our ADU offers completely privacy for it’s residents as well as for the main house. It and has rooms that are just the right size for people to flow throughout the space comfortably. The large windows and high ceilings create a sense that the space is quite large. Design elements such as fir trim, high end light fixtures, and a European kitchen make it feel luxurious. Having two full bathrooms in a small house is pretty great too!
I love how the big light fixture ties in with the guard rail, the fun stained glass transom, and how fixtures in the tiny upstairs bathroom make it feel much larger than it is.
The curb at the street blocked driveway access, and was an unfortunate consequence of shortening the driveway. We wanted to be able to park a small car and have a car charging station.
We would have been more realistic with the level of finishes we wanted, so our budget could have been more on track.
There’s no way I could have worked full time and been in charge of this project. It was very demanding at times.
Think about designing high windows to maximize privacy for surrounding yards. Do not skip doing a survey even though it’s expensive.
The 1906 farmhouse sits on a corner lot with terrific SE exposure for gardening. My wife owned and lived there before we met, and had created a wonderful garden and apple espalier perimeter fence. We’ve been renting it out since then, but have been unsuccessful at finding tenants with green thumbs to keep the garden from declining into a weed patch. For this and other reasons, we eventually decided to sell – and I suggested that we first build an ADU so it could become a miniature garden-oriented community for its next stage in life. Zoning supports an ADU along the SE 71st frontage of the lot, and we came up with a nice layout that allows both homes to share and look out on the garden area, a shared private gathering area in the NW corner of the site (campfires?), and small private yards for each home. Legally, the house and ADU are being sold separately as condominiums. I did this once before (Sabin Green) a decade ago as a proof-of-concept, and welcomed the chance to try it again. This development strategy simultaneously preserves the 110 year old farmhouse and adds a small house that will likely be more affordable than other homes on this street.
Read a blog post about condoization of ADUs on AccessoryDwellings.org
Type of ADU |
Detached new construction |
Current Use | The ADU and primary house are being sold separately as condominiums. The first to close must be owner-occupied. Based on past experience, it’s likely this will be true for the other as well. |
Architect/Designer |
Schuyler Smith, Polyphon Architecture and Design (with design input from Mark Lakeman, communitecture) |
General Contractor |
Orange Splot LLC |
Heating System |
ductless minisplit |
When did you start the design work? |
7/2015 |
When did you submit the plans to the City? |
9/2015 |
When did you start construction |
11/2015 |
When did you get your certificate of occupancy? |
8/2016 |
Total Square Footage |
794 |
Total Cost (including sweat equity) | $200K |
Cost/Square Foot |
$251 |
Sweat Equity estimate (part of the “Total Cost” listed above) |
$0 |
Other special project costs | The sewer line for the main house was in poor condition, so we had to replace it in order to tap in the sewer line for the ADU ($3,900) |
Certification & Energy Scores | EPS (pending) and Energy Star (pending) |
I anticipate both the ADU and primary house to be owner-occupied initially and over time – although there’s certainly the possibility that the owner of the ADU might rent out the second bedroom.
I reviewed the ADU code to make sure it was possible to locate the ADU such that it would have its own street presence. Then I met with my real estate agent to estimate out how much the old farmhouse would sell for as-is vs. how much it would sell for as a condo with a new ADU also on the site. We factored in the costs of designing, permitting and building the ADU, renovating the farmhouse, and navigating the condo process. The numbers looked good enough that we decided to give it a shot. Financing for the project came from a combination of a HELOC and a private loan.
BDS permit review was smooth and swift. The one notable complication related to building separation requirements between the ADU and existing house. This was resolved by fire-rating the ADU’s eaves closest to the existing house and converting part of the ADU to a ‘warm roof’ so there wouldn’t be vent openings within 3′ of the presumed property line between the structures.
My costs are coming in a little higher than I expected, although more so on the renovation of the existing house than construction of the ADU. I won’t know my return on investment until we actually sell the homes. But I suspect it will turn out be a financially sound project, since home values continue to climb from when we did our initial projections.
Fiberglass windows, Energy Recovery Ventilator, High-efficiency water heater, natural woodwork (including ‘live edge’ windowsills), cellulose insulation, front porch ecoroof, induction range, Energy Star certification, wool carpet upstairs
We’re quite happy with the traditional craftsman shape of the ADU and how it relates to the farmhouse already on the property – while also adding a few modern flourishes (flat eco-roof porch roof, roof gable the projects out at a slant…). We also like its efficient interior layout that gets 2 nice sized bedrooms and full bath upstairs and a large-feeling ‘great room’ downstairs. We took advantage of the opportunity to paint the exterior of both the ADU and original farmhouse at the same time, giving the project a bright, fresh look with color schemes that play off one another.
We used natural woodwork throughout, including ‘live edge’ window sills. In both the ADU and main house, we’ve integrated metal art into the design of front porch seat brackets, railings, and trellis supports. We’re also pleased at how the site layout provides focus for the more public parts of the homes towards the garden and street, with more private areas in the upstairs and towards the back portion of the property.
Some neighbors expressed concern about the ADU being close to the street rather than tucked in to the back corner of the property. Early in the design process, we slid it back several additional feet in response to this feedback. This was definitely a compromise to our site plan, since it meant a larger portion of the ADU’s living area ended up being behind (and partially shaded out by) the existing house. Also, it limited the view of the ADU to the shared garden area. But by setting the ADU back a little further from the street than allowed, we made it more in line with existing setbacks in the neighborhood – and it’s still possible to look into the garden from the ADU kitchen and entry, which should help the ADU residents feel a sense of ownership of that part of the property.
Overall, this project went quite well. There were a couple times during construction when we had some down time while trying to get onto a subcontractor’s schedule and/or when our in-house staff got overly-busy with other jobs. This created a loss of momentum and almost certainly led to modest increases in construction and carrying costs. More attention to keeping the schedule moving would have been helpful – although in the context of today’s frenetic construction environment, that might have been hard to pull off.
When you have a complicated roof design and run most of the 2nd floor rooms to the underside of the joists, ventilation gets complicated. In some cases, we ended up having to switch to a ‘warm roof’ detail because more traditional ventilation became impractical.
If you’re going to sell the house and ADU separately as condos, remember that the main house’s value will take a hair cut since it will be losing some yard area and becoming a condominium. But at the right location, I think this can be a good strategy. Passers-by have expressed lots of interest in this small, relatively affordable home buying opportunity in a great neighborhood. Same would probably be true in other parts of town.
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