Accessory Dwellings

A one-stop source about accessory dwelling units, multigenerational homes, laneway houses, ADUs, granny flats, in-law units…

Tatiana & Rafael Xenelis-Medoza’s ADU: A Hidden Gem

Xenelis-Mendoza ADU

Xenelis-Mendoza ADU

Quick Facts

  • Setting: urban
  • Neighborhood: Portsmouth, Portland, OR
  • Type: basement conversion
  • Use: long-term rental
  • Square Footage: 750
  • Year Built: 1924
  • Conversion Year: 2015
  • Owners: Tatiana & Rafael Xenelis-Medoza
  • Designer: Tatiana & Rafael Xenelis-Medoza
  • Builder: general contracted by owner
  • Total Cost: $55,000


Tatiana Xenelis-Medoza is a realtor so out in the field in her daily interactions with people she started to hear the terms “ADU,” “granny flat,” and “mother-in-law.” (See The Many & Confusing Synonyms for ADUs for more on that!)

“I started to read tidbits online. Something stuck with me in the beginning of 2014, and I enrolled in Kol’s class in March of 2014 so I could become more familiar with all the ins and outs and details of an ADU. And then things moved really quickly. We found a house with ADU potential and were lucky enough to get under contract just two months later and close in May of 2014.” – Tatiana Xenelis-Mendoza

Several key factors convinced Tatiana it was time to create an ADU on her own property in addition to helping her clients find them. She explains that on a personal level the return on investment was appealing and on a professional level she supports urban density and infill housing.

Xenelis-Mendoza ADU Great Room

Xenelis-Mendoza ADU Great Room

“We were definitely inspired by the option to cut our mortgage payment in half, but the primary motivator was designing something that will fit in with the neighborhood rather than starting from scratch with raw land. I’m a firm believer in urban density, in a smart way, not just creating density through high-rise apartments. It’s appealing to me to create additional units within the urban space on a lot that’s already built out and landscaped.” – Tatiana Xenelis-Mendoza

As Tatiana and her husband Rafael looked for a new home, accommodating an ADU was a key criterion. For Tatiana’s expert tips check out How to Buy or Sell a Property with an ADU (or ADU Potential).

Xenelis-Mendoza ADU from Street

Xenelis-Mendoza ADU from Street

“We were looking for a house with the potential for an ADU. This particular property is a corner lot and it has a backyard that was accessible from the side street. The house sat and faced forward on one street and the new door from the ADU is accessible from the corner street.” – Tatiana Xenelis-Mendoza

The house they purchased in Portland’s Portsmouth neighborhood had potential for a basement ADU, with one major caveat: they didn’t have the code-required ceiling height of 6’-8” for a basement ADU.

Xenelis-Mendoza ADU Kitchen & Laundry

Xenelis-Mendoza ADU Kitchen & Laundry Room

“We were pretty disappointed when we realized we did not have 6’-8.” We had 6’-5.” We decided we were going to go for it anyway. We ended up excavating the basement and rebuilding all the foundation footings. We took out the old 1924 posts and the post footings. My husband relocated these so they would be inside the framing and walls. We took out the old gas furnace and duct work, which also opened up ceiling. We were able to go a little above the minimum ceiling height. Taking the basement ceiling to 7’2” completely transforms the space. We used light and bright paint and stained the concrete floor with an espresso brown, which makes the space feel bigger than 750 square feet. We get feedback that now it doesn’t feel like a basement at all.” – Tatiana Xenelis-Mendoza

Their other big setback was that the new electrical panel in the basement was challenging and very expensive. The electrician had to split off the panel and bring everything up to their unit, then provide a separate panel and meter for the ADU. Luckily, since they only have two bedrooms and one bath on the main floor, they didn’t need to upsize the water meter as they feared they might.

With the parameters of the structure figured out, they explored their design possibilities within the space. They had two key considerations: how to incorporate two bedrooms and how to bring in as much natural light as possible. They added egress windows in both bedrooms and a large window in the living space to bring light into the kitchen. They also spent a lot of time trying to figure out how many can lights to put in each room to provide adequate lighting for Portland’s gray winter days. One of their design inspirations was a garage conversion they saw on a tour in 2012.

Xenelis-Mendoza ADU Bathroom

Xenelis-Mendoza ADU Bathroom

“My husband and I went on the Build It Green Tour and saw little ADU garage conversion in Ladd’s Addition. It was small, but well laid out with stained concrete floors and a bright kitchen. That ADU gave us a lot of ideas and inspiration.” – Tatiana Xenelis-Mendoza

Tatiana and Rafael tried to build in storage, too. The ADU has a laundry with additional cabinets and the bathroom has quite a bit of storage. They did an Ikea bathroom and they built shelving around the sewer pipe. They also bought enough room for an actual utility closet where the furnace used to be when they replaced their old gas furnace with new cadet heaters. They found that the new Cadet style is so much more efficient than the old ones that they needed just four of them to heat the ADU. They also installed an electric on-demand water heater which is efficient and doesn’t take up much space.

Xenelis-Mendoza ADU Bathroom Storage

Xenelis-Mendoza ADU Shower & Bathroom Storage

“It started to come together when we sheetrocked, mudded, and textured the walls. Then it wasn’t just a big open framed space. That was definitely a highlight! We also had a ‘happy accident’ in that we had leftover juniper lumber after building out the window wells so we incorporated by doing live-edge juniper into the open shelving in the kitchenette and the pantry.” – Tatiana Xenelis-Mendoza

Tatiana and Raphael funded their ADU entirely with cash reserves and they did most of the work themselves. They subcontracted with several companies, including Bob Willett Construction as their go-to contractor.

“It took us six months longer than anticipated because we ran out of money. We thought we could do it for $35,000, but the electrical was quite sizable. That was nearly as much as excavation and pouring the new slab. However, it’s still a good return on investment. We anticipate it will be a 3.8 year payback period.” – Tatiana Xenelis-Mendoza

Tatiana and Rafael recognize that they could recoup their investment more quickly if they used their ADU as a short-term rental, but they have settled on a long-term rental and it’s working well for them.

“We toyed with whether or not we wanted to use it as an Airbnb. We may consider that in the future, but we our plan is to live here for another year or two and then move on from this and rent out both the upper unit and basement ADU.” – Tatiana Xenelis-Mendoza

(Read about Options for ADU Owners: Rent One, Both, or Neither.)

Tatiana says there’s not much interaction between her and Rafael and their tenants because of the way the units, yards, and access are split up.

“We hardly see them at all actually. We ended up splitting our backyard. They have a private backyard and we have a private backyard. They have their own entrance. They can  park on the street and go into the rental on the side street. In fact, we end up sending notes to each other. It’s been really rainy recently so I put a note on their door the other day that asked them to let us know immediately if there are any leaks in the basement.” – Tatiana Xenelis-Mendoza

Tatiana’s has two happy surprises regarding her ADU:

  1. The first is that she and Rafael don’t hear their tenants: “We tried really hard to make it as soundproof as possible. We used Roxul mineral wool insulation and Quiet Rock Sheetrock. For such an old house, it’s pretty quiet.”
  2. The second is that their 750 square foot, two bedroom ADU is nearly invisible from the street: “This two bed fits in really well. I don’t think anyone from street would know we have a 2-bed unit in the basement other than the address marker.”

Tatiana is really happy with the final product and doesn’t have any negative feelings about her ADU. She’s especially proud of how they transformed that space so it feels more open and bright.

So what advice does Tatiana have for homeowners considering creating an ADU on their own property?

“I’d probably take your budget and then factor in a 20% contingency.  I would also try to find reliable subs. We lost a lot of time with our subs who disappeared for half the job and then came back. We piece-mealed it together and my husband did a lot of the work, but we were also trying to use subs to make it go along quicker. I’d be more stringent when I interview a sub for the job. I know what my limits are now and what I expect, so I’d be more candid about those expectations.” – Tatiana Xenelis-Mendoza

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 “Tatiana & Rafael Xenelis-Medoza’s ADU: A Hidden Gem

  1. Pingback: Tips for Basement to ADU Conversions | Accessory Dwellings

Comments are closed.

%d bloggers like this: