Chicago people, what's the rough cost of finishing an attic?

Question

Space is about 800 square feet, duplex up from the second floor. It has already been dormered and ceilings/walls insulated. Two stair cases already in place. Would need to add a few walls to create 2 bedrooms and build a budget bathroom. Needs flooring. I don't need walls painted (wife and I love painting).

I know this is a very open-ended question, just looking to get a ballpark. Am I looking at like $40k or more like over $100k?

Or anyone have a GC in the area that they'd recommend that I can chat with?

Crystal Smith · Answer

We budget $15K for planning purposes.

Crystal Smith · Answer

Since it's already been dormer and ceilings/walls insulated I'm going to assume that the MEP is already in place. Your major cost will be adding the bathroom. No such thing as adding a budget bathroom in Chicago anymore. Because you will be using more water the city will add requirements for the extra bathroom that will drive up your cost. With that said, unless you get a contractor that is ridiculously expensive, you should be able to do it for less than $40K. Since you'll be doing the painting, why not do the flooring or have a handyman do the flooring.

Daniel C. · Answer

@Crystal Smith Hi Crystal - I've been wondering about something you mentioned and did ask an Architect over a virtual meetup but didn't get a super clear answer as it pertains to the ADU Ordinance. Does this part of your message basically equate to having to upgrade the water service? I.E. digging up the trench along the property, sidewalk and potentially the street to run a larger water line?Because you will be using more water the city will add requirements for the extra bathroom that will drive up your cost

Crystal Smith · Answer

That’s exactly right. You’ll have to upgrade the water service to the home when you add the new bathroom. We added many bathrooms to homes without having to do this at a reasonable cost. This requirement drove up our cost significantly

Eudith Vacio · Answer

Hi @Bradley Koerner - $40k sounds about right but I would guess those estimates would change depending on type of materials. Check with @Jonathan Klemm, he's a local GC and he can probably give you an idea of the cost to build.

Jonathan Klemm · Answer

@Daniel C. - Try checking with @Prashanth Mahakali or @Samuel Pavlovcik regarding Chicago architect questions. If you are adding space to a property you are typically going to be required to get drawings and permits, especially if you are adding any bathrooms or electrical features.

Daniel C. · Answer

@Crystal Smith Thanks for confirming! I have a similar building to the OP where I have an attic with enough space for duplex up or add third unit as part of the ADU ordinance and doing some initial investigation if either option is worth it in terms of the cost/work involved Assuming the work to run the new water line is another 20 - 40k from a few older comments on BP I remember reading through? I think one person had called out what side of the street you were on would dictate a portion of the cost because it would be significantly more expensive if you had to dig up and replace that as well. The water line in the basement is about in the middle of the lot, not sure if that varies much across Chicago properties and some come in through the front of the basement/building

John Warren · Answer

@Bradley Koerner you already have a lot of great advice here. Really you will need to be more specific with your scope of work to get more information. It this a flip or a rental? Are you holding onto this for a long time? You will need to determine what types of permits you will use as well. If you don't do a bathroom then you will save probably 7-10k based on plumbing and electrical needs for a bathroom. If you are doing this on the cheap, then you are likely not going to use a full blow GC. Instead, you will use "a guy' who will have a small crew that can knock out framing, flooring, drywall, etc. There just won't be enough margin in there for a pro like @Jonathan Klemm. If you are doing full plans and permits, you are probably closer to that 80k mark if I had to guess. You are adding a few grand for drawings, you are adding all the rough inspections and final inspections for the trades, and you are adding all the trades like plumbing and electrical.

Jonathan Klemm · Answer

@Eudith Vacio thanks for the tag! Hey @Bradley Koerner - I think you are in the right ballpark assuming there are not a lot of MEPs (Mechanical, electrical, & plumbing) going into the area. You'll definitely need mechanical and electrical but maybe no plumbing as long as there isn't a bathroom.Is this a project you are planning to pull Chicago permits? Because a lot of times that can cause you to do more work than you were originally planning.