Separating a duplex attic to become an independent apartment
So, I got a duplex a few years ago and finally got around looking at the Columbus zoning map, it turns out that the building is already zoned for three units, not two, I want to turn the attic into the third unit, I’m thinking to add a proper staircase fire escape and run independent utilities up to the unit through one side that’s currently under construction. I don’t know anything about this process and am hoping someone has some insight. I know that if I put a door between the units, I’ll meet the square footage requirements for headroom, but other than that, I’m not sure how to proceed.
Quote from @Walker Furpahs:
So, I got a duplex a few years ago and finally got around looking at the Columbus zoning map, it turns out that the building is already zoned for three units, not two, I want to turn the attic into the third unit, I’m thinking to add a proper staircase fire escape and run independent utilities up to the unit through one side that’s currently under construction. I don’t know anything about this process and am hoping someone has some insight. I know that if I put a door between the units, I’ll meet the square footage requirements for headroom, but other than that, I’m not sure how to proceed.
Do you need to raise the roof? I would check with zoning for the area your property is in. You do not want to start on the outside without getting the permits you might need. Another thought is to run the numbers and see with how much you spend on this if it will be worth it? Would it be better to just buy another property with all the money you will spend to fix this up?
If your structure isn't built for having a 3rd living unit (not just a simple extra room up there), your dead from the start! Unless of course you change it ... :)
I would start by finding an engineer who can tell you if your floor system and lower level framing can support a 3rd apartment. then figuring out egress and best way to run utilities up there. another thing to think about is if you can support parking for 3 units i.e. street, back of lot, etc.
Quote from @Walker Furpahs:
So, I got a duplex a few years ago and finally got around looking at the Columbus zoning map, it turns out that the building is already zoned for three units, not two, I want to turn the attic into the third unit, I’m thinking to add a proper staircase fire escape and run independent utilities up to the unit through one side that’s currently under construction. I don’t know anything about this process and am hoping someone has some insight. I know that if I put a door between the units, I’ll meet the square footage requirements for headroom, but other than that, I’m not sure how to proceed.
What are attic conversions similar in size in your area renting for? How about the value of similar properties that have the attic conversion compared to those that don't? I'd want to know that to get a rough idea if the expense of the conversion is worthwhile and better than building an add-on or purchasing another property entirely. If making it an independent unit isn't feasible or efficient, I'd consider if there's any value improving it enough to at least add sq ft to one or both units.
I'd also consider what impact if any, would adding a third unit have on the other two tenants as now that's three families sharing common areas and parking if applicable. I don't mean in terms of feeling sorry for them rather, does it make the other two units less desirable and command less rent.
After that, as everyone mentioned, is getting familiar with zoning requirements relative to your attic, and how many livable square feet area allowed on your lot for its size.
That's a short list, but I'd want to know all that before getting estimates.
i want to thank everyone for their thoughtf replies, I’m in the midst of getting ahold of architects and engineers. With regard to parking, everyone on the block is street parking, I have a huge backyard for my neighborhood, long term plan is build a garage with an apartment on top. Short term plan is finish demo/reno the other side. Between the two attics I’d have close to 800-850 sqft which in my area is renting for 1300+ It’s an old house with a large flat roof, so the attic ceilings are almost 10’. I’m planning on doing two master baths on the other side with large bedrooms, this will easily fetch 3000+ likely more by the time I’m done. So after my appointments with engineers and architects I’ll know more. My plan is to refinance after having the renovations to build a big ole garage. But there’s still a lot to figure out.