This project spotlight shares the design process for a detached accessory dwelling unit in Columbus, Ohio. Find out more about this project on our project page.
In today’s post, we’re sharing our latest project, Huron ADU. Follow along as we take you behind the scenes of this exciting project.
Huron ADU is a 572sf backyard studio apartment in Columbus, OH. More specifically, it’s an adaptive reuse project in which we’re converting a detached 2-car garage into an accessory dwelling unit (D-ADU) – the first true garage conversion in the Columbus.
Project Specifics
This small project is actually a personal project – I own the property together with my partner. We’ve always talked about developing projects so we thought this would be a great small project to start with – to learn from, to get involved in the construction process, and ultimately to provide Columbus with an alternative model for affordable housing. (More on this in a future blog post.)
So we’re wearing a lot of hats acting as the architect, the owner, and builder. We’ll be getting our feet wet with the design-build delivery method and the owner-build method. There will be a lot to learn for sure, and we’re bound to make a few mistakes. But that’s OK, experience is the best teacher.
Also, here’s surprise: We plan to live in it when it’s finished. We’ve been talking a lot about simplifying our lives, living with less, and enjoying life’s adventures. We see this as a way to do achieve that.
Our plan is to live in the Huron ADU and rent out the main house (hopefully to Americorps workers serving in the neighborhood). And then if/when we’re ready to start a family or have parents move in, we’ll move back into the main house.
Program
The project program is quite simple. The studio apartment will include a full kitchen, bath, sleeping area, and loft space for an office and lounging.
Because we’re converting an existing space, the footprint is already defined for us – it’s a 22’x22′ square. (Just for the record, squares are hard to work with. We would much rather have a rectangle.)
Site Plan
Existing Conditions
With a net footprint of 400sf, we knew we would have to be creative. At the same time, we didn’t want to compromise by making things “tiny”. We want the space to feel like a normal house, only smaller – so full sized kitchen and bath and spaces that would serve more than one function.
The ground floor will have a kitchen, bath, and sleeping area. The sleeping area will have a murphy bed which will also have a large concealed table and moveable seating (yet to be designed). The upstairs loft will be an office with two workstations and a tv lounge area. Because we will no longer have a garage (we don’t need a house for our cars, there are so many people in this world who don’t even have a house), we are adding an enclosed exterior storage wall for smaller outdoor items.
Floor plans
Design
The Huron ADU design was intentionally kept simple and conventional. We looked at various roof schemes (pitched roof, flat roof, gable roof, dormers) and kept coming back to a simple gable roof. It would be easier and cheaper to build and still met our needs. Plus, many of the houses in the neighborhood have gable roofs and lap siding, and we wanted the studio apartment to blend in within the neighborhood, and more specifically with the main house.
The one downside to the gable roof is that at the loft level, the ceiling height is lower at the sides so you have to dedicate the middle as your circulation zone and push your furniture to the sides. Obviously, you could have built higher, but we wanted to keep a modest height.
We chose to keep the sleeping area on the main level because we felt the proximity to the bathroom was important (and trying to squeeze the sleeping area and bathroom upstairs didn’t work out nicely). We also felt that separating the office and tv watching area from the main living space was important. We aren’t big tv watchers so keeping that area tucked away upstairs works for us. And I’m all about having better work/life boundaries so the floor change will help with that.
Exterior Perspective
Interior Perspective
Our biggest concern was making sure we had a lot of natural light in the space. The last thing we want is for the space to feel dark and cramped (and like a garage). So we opted for a lot of windows and skylights to flood the space in light. Our material choices, though not finalized, include a light calming palette of woods, whites, and blue-grays.
We aren’t quite finished with the design yet even though construction is underway. This has caused some anxiety since I’m used to having things more figured out and drawn up. I guess this is part of the design-build mentality… some things, we decided, would have to wait. There just isn’t enough time to do it all up front when you have a deadline you’d like to hit.
Things we still need to figure out include the stair, railing, casework, window details, and the interior material palette. We’ve been going around and around on materials and stair/railing design, weighing cost with style and constructability while trying to make the best decisions based on those constraints. It has been tough.
Planning Approval
One of the biggest hurdles we had to overcome during the design process was planning approval.
Columbus, OH doesn’t have any language in its zoning code for ADUs (yet) so we had to obtain a council variance to allow two dwellings on one lot. And not just that, we needed to get nine other variances for the project. Only a few of those variances actually addressed our proposed project. The others addressed non-conforming conditions inherent with the lot.
The variance process started with a conversation with the city’s chief zoning official and two case managers who explained the variance process and spoke more specifically about our project. They were actually excited to help push this project forward because they saw this as a viable and alternative housing type for the city. Following that meeting, we worked on gathering and submitting our variance applications along with all the required supporting documentation and waited to receive comments back from the various city departments who reviewed our application. At the same time, our paperwork was sent to the neighborhood area commission which required us to present our case to them.
After two neighborhood area commission meetings (one with the zoning committee and the other with the full commission) we received their support and recommendation. This recommendation wasn’t completely a walk in the park. We had to speak to neighbors and other community members, hear from dissenters and get questioned by people who didn’t quite understand why we wanted to do this project in the first place.
In the end, we received the neighborhood commission recommendation which was forwarded to the city to ultimately allow our case to be presented in front of the city council, which was also a nerve-wracking experience. But after four months of paper-pushing, getting recommendations, and going through all the motions, we finally received planning approval for the project.
Because we had to submit a site plan and elevations already for planning approval, we only needed to finalize the plans, sections, wall sections, and schedules to submit to the building department for permitting. Within a matter of a few weeks, we received our building permit!
Construction
There will be a lot to learn, but we’re eager to jump in. Fortunately, we deliberately kept the design fairly conservative and straight-forward so as not to over-complicate things. We’ll be personally doing as much of the construction as we can along with a few friends and family members, and then will subcontract the stuff we can’t (or don’t want to) do like utility connections, MEP systems, concrete, and masonry.
This means that I’ll be stretched pretty thin for the rest of the spring and summer, sacrificing some design time to build and manage the construction. The goal is to finish in August.
And did I mention our construction budget? It’s $65,000, which is VERY ambitious so we’ll have to get creative with how we spend the money. We’ve made some compromises already, but are also choosing to splurge in a few places so this won’t be a cheap-looking build by any means. So far, our biggest splurges are on glazing, stairs and railing. And our biggest savings are due to networking, bartering, and sweat equity (design, construction management, and construction labor – most of which we are doing ourselves).
Here’s a quick breakdown of our budget:
We’ll see how close we get to this budget. We’re expecting some overages and splurges but we’re also trying to be smart about it.
Summary
In the end, we’re happy with the design and decisions we’ve made.
We’re excited to move forward with this project because it checks off boxes in so many areas of interest for us… adaptive reuse, repurposing materials, small space design, cost-saving strategies, sustainable community development, and architect-led design build just to name a few.
Because this will be our home, we’re designing it to meet our specific needs but also remembering that it will one day house someone else. It’s not our forever home, but it will be one that we will enjoy for the years we’re in it.
What type of slab are you using. I have been looking at frost protect shallow slab foundations. I have been speaking with the Mono Slab EZ Form people and their distributor Brock White here in Wisconsin. Fully insulated under slab for energy efficiency and simplicity.
Hi James,
Yes, we will have a frost-protected shallow slab foundation under the existing garage door openings since there is no foundation there. The residential code prescribes the size, depth, and insulation requirements for the thickened slab edge. In our location, we need a 12″ deep thickened slab edge along this opening and then it can taper back to the standard 4-5″ thickness everywhere else. The entire edge and underside of the slab will be wrapped in R-5 insulation board. All of this is something our concrete sub can easily do when he pours the slab so its a much more cost-effective solution to a traditional footing and foundation wall (which would have required more excavation, more materials, and a few thousand dollars more). Thanks for the comment, Cheers!