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John & Stephani Hayden’s ADU: An Expertly Executed Basement Conversion

Hayden ADU Kitchen

Hayden ADU Kitchen

Quick Facts

  • Setting: urban
  • Neighborhood: Overlook, Portland, OR
  • Type: basement conversion
  • Use: short-term rental
  • Square Footage: 625
  • Year Built: 1923
  • Conversion Year: 2015
  • Owners: John & Stephani Hayden
  • Designer: John Hayden
  • Builder: John Hayden
  • Total Cost: $25,000 (for material, permits, fees but not including owner’s sweat equity)

“The great thing about having an ADU is how you can use it in so many different ways. We anticipate changing its use depending on our lifestyle. Right now sharing with family and friends makes sense. In the future we might rent it long-term. That’s the magic of an ADU.” –John Hayden

John Hayden was very familiar with ADUs before he began his basement-to-ADU conversion last summer because he had worked with a project management company in the Bay Area that specializes in ADUs.

Hayden ADU Living

Hayden ADU Living

“I had a unique experience with a project helping homeowners create ADUs, which shed light on the concepts in a positive way. After helping homeowners firsthand, it convinced me to create my own ADU. I had an overall management perspective and understanding in terms of cost and return on investment. I saw many people investing $150,000 or more in ADUs and planning for a 10 year return on investment. We wanted to do it more affordably so focused on a basement ADU, which requires much less cash upfront.” – John Hayden

John and his wife Stephani decided to use their savings to purchase a house with potential for a basement ADU. (You can also read more about basement-to-ADU conversions, including information about two other basement ADUs that will be on this year’s Build Small, Live Large ADU Tour in an article written by Janet Eastman for the Oregonian called Small Budget, Big Addition: Basement Conversions.)

This investment would provide flexibility in terms of both their finances and their housing options. The recent birth of their first child also inspired Stephani and John to find a way to have friends and family close by.

“We have a two-year-old and my wife is from Washington, D.C. Our families visit and like to spend time with our son. We wanted to have a space where they could stay, but also have the opportunity to rent it out, short or long-term. When we decided to build an ADU, we focused on properties having a basement with an exterior entrance and adequate head height. It took a while but we did ultimately find one.” – John Hayden

As they designed their ADU, John was inspired by the families he’d worked with and the multitude of reasons they’d created their ADUs.

Hayden ADU Dining Room

Hayden ADU Dining Room

“I was intrigued by the flexibility to travel, bring in rental income, and take care of family members. That lead me to the project in the Bay Area. Once I was working there it was no longer just stories on the internet, but real stories of real people. Listening to all the ways they planned to benefit from their new unit, I was inspired to see how easily it could be done if approached the right way. Owners can make the project overly complicated, and our intention was to keep it simple.” – John Hayden

John explains that when a homeowner is remodeling rather than building from scratch, some of the design decisions are made for them, such as where the furnace and plumbing are located. The size and shape of the available space are also key considerations.

“So you figure out where the bathroom and kitchen will be and think about how to create a flow. Six hundred square feet will give you room for several areas: dining, kitchen, bedroom. We went with a modern, open layout.” – John Hayden

Hayden ADU Living & Bedroom

Hayden ADU Living & Bedroom

John and Stephani kept their costs down by doing some of the work themselves and by calling on the expertise of friends who are plumbers, framers, and electricians. They appreciated the way friends rallied around the project and enjoyed the hands-on, community-oriented feel of their renovation project. Of course, not everyone has the skillset John and Stephani have, but they encourage homeowners to consider doing-it-themselves as much as they’re able.

Interestingly, even with his background developing ADUs, John faced a couple challenges in the construction of his own ADU because basements often present special conditions – and sometimes special surprises. During their build, the two biggest challenges were electrical and fire walls. Stephani and John had to have the electrical main moved from one side of house to other because the mast wasn’t tall enough, so they ended up rewiring.

“The most frustrating was the fire wall between the two units. In the ceiling you’re supposed to have ½” fire rated drywall. Each light fixture needs to be in its own fire rated box, which has to be custom built and mounted in the rafters. We have 26 fixtures so that was an expenditure and created time issues we hadn’t planned on. I’ve learned a lot about these projects but there are always unexpected twists with each specific property. No one can predict everything but good planning minimizes those surprises.” – John Hayden

He’s grateful that he found so much support from the city throughout the process of figuring out the details of the basement-to-ADU conversion.

“Working with the City of Portland Building Department was a great experience. They were very understanding, especially working with me as a homeowner. It was interesting, though, when I learned that inspectors were a totally different department and had their own, more strict, protocol.” –John Hayden

When describing the sustainability features of his ADU, John noted that converting existing space to an ADU is sustainable in and of itself because conversions take advantage of existing structures to create additional livable space.

Hayden ADU Bedroom

Hayden ADU Bedroom

“We used all LED lighting and extra insulation in the exterior walls. We also put in a key card switch for the heater. The keys are attached to a key card that pulls out and shuts down the heater. So when renters leave, they take the keys with them and the heat turns off. When they return they put the key card back in place and the heat comes back on. They have to be physically in the unit to have the heat on. Everyone wants to talk about it. Some of them say ‘I’ve seen these things in Europe and Asia,’ but they’re uncommon here so with almost every guest it sparks a positive conversation about energy.” –John Hayden

John also points out that the earth surrounding the unit moderates basement temperatures. They installed new Cadet style heaters, mounted higher up on the wall. Stephani and John are pleased with the heat system in the ADU, but it wasn’t what they’d originally planned. They had planned on sharing their furnace with the ADU but learned that in Portland an ADU needs its own heat source. The cadets were a relatively inexpensive and simple way to provide a separate heat system. John also points out that they help with sound since there aren’t any ducts carrying sound from one floor to the next.

Stephani and John are using their new property as they anticipated they would: they live in the primary dwelling and friends, family, and short-term renters stay in the basement ADU. John says that when family members or friends stay, they open the door that separates the ADU from the house to make it easier to interact. When renters stay, Stephanie and John become short-term property managers, sharing information about must-see sites in Portland. John says that he always felt the ADU project was moving in a good direction, but the biggest highlight was having their first short term renter tell them how much they loved the space.

Hayden ADU Bathroom

Hayden ADU Bathroom

“That was the ultimate goal. When you see a raw basement and the floor’s opening up and plumbing lines are running through and you’re rewiring, it’s hard to believe it’s going to turn into a beautiful space. We had some anxiety about how it would feel and if we could really turn this dark basement into a bright space people would enjoy. We kept asking ourselves, is someone really going to be able to be in our basement and like it? They do. So having that happen was rewarding.” –John Hayden

The ADU is currently serving Stephani and John’s needs very well and they anticipate that it will continue to do so in the future.

“We should have a quick return on investment and our friends and family are able to stay with us with a bit of separation so they can have their privacy. I really like the fact that so many parties can benefit from it: us, family, friends, people visiting. It’s hard to pinpoint any negative aspects of the concept.” –John Hayden

When pressed, John says at this point there isn’t anything that he and Stephani dislike about having an ADU. However, he points out that they’re still in the honeymoon phase. He also notes that it’s an added level of responsibility, since there’s always something to think about. Whether they are doing an additional improvement or just preparing for the next renter, it’s another thing to be mindful of and responsible for. John says that’s not a negative thing, since he and Stephani have time to take care of these responsibilities, but it is additional work, especially for home-owners who decide to rent their ADUs out as short-term rentals.

Of course, many units designed as short-term rentals have storage space like a hotel room – enough room to tuck away a week’s worth of clothes and a toothbrush, but nothing else. John and Stephani didn’t take this tack when designing their ADU.

“The basement is 800 square feet and we wanted a blend of personal storage for us but also adequate storage for the unit. We wanted flexibility to rent it long-term, so we made big closets and storage space for the type of person who would be living there and having more things. If the plan was just to do short term we may have made it smaller and saved more storage room for us, but we wanted the flexibility.” –John Hayden

John says what he wasn’t expecting is the level of interest that other people have about it. It seems to him that ADUs have reached a tipping point in terms of awareness.

“I was under the impression ADUs were a niche idea that only a small percentage of people were considering them, but there’s a tremendous amount of interest among friends and acquaintances, wondering if it would work for them, too. It’s nice to be able to share my experience with them and promote more ADUs around town.” –John Hayden

John has created a website called Golden Basement to help other people learn about basement conversions.

So what advice does John have for someone considering creating an ADU?

“Creating a second unit can be a fair amount of work but the long-term benefits are well worth it. Sharing your property with others isn’t for everyone, but for those who are open to the idea, it opens up a world of possibilities.” –John Hayden

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.

12 comments on “John & Stephani Hayden’s ADU: An Expertly Executed Basement Conversion

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  2. Martin John Brown
    May 24, 2015

    It’s great to hear about a more economical project. I’m surprised more people don’t go for basement conversions, especially if the goal is rental income. Rents for attached ADUs (such as basements) are nearly as high as detached, but construction costs are typically much lower.

    However, there is the privacy issue. Wood floors and joists above really tend to transmit sound. In particular I am wondering if John did anything special for the purpose of soundproofing? Thanks!

    • John Hayden
      May 29, 2015

      Hi Martin, you’re right about sound. We studied this quite thoroughly and opted to use resilient channels to drop the ceiling drywall slightly below the rafters to minimize vibration and then also filled the space in the rafters with thick insulation. The outcome has been great and there are even more methods available if you want further sound controls.

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  4. Matt McComas
    October 12, 2015

    Hey Martin, question about sound in the ceiling. With our basement ADU the city of Portland was very specific and wanting sound batting, resilient channels and two layers of 5/8’s sheetrock to get the correct fire rating and sound rating. What else did you do for the ceiling assembly?

    • Matt McComas
      October 12, 2015

      ooops. meant to say John

      • john
        October 13, 2015

        Hi Matt. I don’t think there is any code that calls for more than one layer of 5/8 sheetrock for fire rating. I also don’t think there’s any code for sound insulation and there is no “correct” rating. It’s completely up to you how much you protect for sound.

        I understand it’s difficult to know how much to do for sound and there are many factors involved. Resilient channels work great for vibration (footsteps, etc), IF they are installed correctly. Read up on that. Sound batting is another fairly efficient way to take care of other sound like voices. The second layer of sheetrock may or may not be worth the cost to do it. But if you do it, you should look into that insulating gel that goes between sheets.

        Other things to do are lay down carpet or rugs with thick pads upstairs. You can also try to take care of squeaky floorboards in main walkways before you finish the ceiling of the basement.

    • linamenard
      October 13, 2015

      Hi Matt,

      Lina here. I’m the coordinator for the ADU Case Studies Project. I’m going to send a note to John to see if he’s able to address your question. Please stay tuned!

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  6. Jenny
    July 19, 2016

    I’m so curious about the key card on the heaters, can you post a picture with the setup or post a link to what you used? Thanks!

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

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