Yep, although our agents suggested we may want to widen the staircase a bit. They think it was originally intended to be a 2-flat (there is an enclosed back staircase with separate entrances onto both floors, and other design quirks that made them think so), but maybe the original builders ran out of cash to build a brick second floor and cut their losses by making it a single-family house. Maybe the basement ceiling is also extra-high for the same reason and was intended to be a garden apartment? Who knows.
I’ve gotten estimates for significant home construction projects including adding 2nd stories, additions, attic build outs, as well as HVAC and rewiring. In my experience pricing can vary widely. Like, I had one project quoted at $80K, and the same project from another contractor quoted at $220K. It’s bizarre. I assume some element of quality, labor costs, and materials factor into this but I couldn’t predict based on the conversations I had with the different contractors. I’d recommend getting several estimates which is a pain in the ass and be up front about that - ask them each to evaluate the other’s proposals.
Power consumption now is much higher than it was when a lot of older homes were built. When you are reworking your panel make sure you communicate that you plan to expand and need to have a higher load, as well as additional circuits. Even existing circuits could need replacement due to wear.
Good luck.
Cool, to have all the “space buildout” done for you like that. I grew up in a house that was apparently planned to be much larger, and then the builder ran out of time or money and did all kinds of bizarre things to finish it off and make it livable. Over the years, we found the original front door framing (in the master bedroom wall) and stopped plumbing in odd places. Weird house. Half adobe and half postwar salvage. You could read the crate markings on some of the attic lumber…
I think it would be better to cross that bridge now and remodel so that the master bedroom is on the first floor and kids/guest bedrooms and less frequent usage space is on the second floor. Thus when you retire you have the option of living almost entirely on the first floor (the second being used for guests and storage of little used stuff).
There are no kids, and I am not knocking down walls and ruining beautiful vintage woodwork on the first floor. The main reason we want to do a master suite on the second floor is that there’s no room in the first-floor bedrooms for a king-sized bed (and we want to add a second bathroom somewhere anyway), but if we need to use a queen-sized bed for a while in one of the first-floor bedrooms, that’s fine. But I will talk to whatever general contractor we end up with about adaptability/accessibility issues, for sure.
Building codes change over time, and she might be held to the new code if she’s converting attic space to living space.
How wide is the staircase now? If it doesn’t meet code (and there are a lot of code issues around a staircase), you’ll have to bring it up to code during the remodel.
Code issues:
Width.
Handrails
Height of risers (absolute height and variation from step to step)
Depth of the treads
If there are turns, then the landing has to be a certain size and if it’s a winding staircase, that’s a whole other matter
Headroom from stairs to ceiling
Probably more, but that’s just off the top of my head.
You mentioned three first-floor bedrooms. Are two adjacent to each other? Perhaps they can be combined to make a comfortable master suite (with a nice walk-in closet and full bath).
But you mentioned that you’ve got an architect whom you know and intend to hire, so he will be able to advise you better than a bunch of strangers on the internet.
True, even if some grandfathered points remain. (The house I mentioned above had some knob-and-tube wiring in the extensions, which can legally be repaired and extended in most jurisdictions; my dad of course ripped it right out… modern code is mostly common sense and good engineering.)
Isn’t that… you know… these days… elitist? 
You’ll be glad you did it that way. I was in the construction and facilities business almost all my working life, but when we had a small laundry room added on, I went with a small A/E firm (one person, actually), which took all the pressure off of us as quality control managers. He made sure the city signed off on permits and that they did the required inspections for electrical/mechanical/structural. Worth every penny. I may have been able to do it myself, but with someone else contracted to do it, I had recourse in case anything went south with the project.
I’ll second the idea that you ought to get an architect to draw up plans if you’re doing more than just reworking existing work.
I’d think that if I were you, I’d roll the other stuff (painting, electrical box, etc…) into your project with the GC; he’s likely to already need to have those subs come out to do that kind of stuff on your attic anyway, so having them put in a new box, paint, etc… is probably actually less trouble than trying to wrangle that yourself.
When we got our kitchen remodeled, our exterior painted and spiffed up, and later our master bath redone, we just tacked on some other stuff, like a new box and some minor demolition outside. Much easier and faster than trying to set it up ourselves.
You’ll need someone to draw up plans for your permit. This is not something a first time home remodeler can do. You might even need the services of a structural engineer, depending on the scope of work. Your architect or designer can tell whether you will need one or not. But no way you’ll get a building permit without a well-drawn up set of plans.
They are all three in a row. It’s a typical Chicago bungalow floor plan, with living and dining room on one side in the front, kitchen in the back, and three bedrooms in a row on the other side of the first floor. The front staircase to the attic leads down into the middle bedroom. I am really reluctant to mess with the floor plan on the first floor; I love my vintage stuff!
Well, let’s see if I can afford him, first 
I had a very nice chat with him for the first time in almost 30 years at lunchtime, and he totally remembered me, but was running out the door. I forwarded him the listing and the inspection report, and we will chat in more substantive detail later. I’m fairly sure that he will give me some good ideas and questions to ask, and I know he’s an honest guy. Looking forward to it!
Are you saying the staircase terminates in a bedroom? That’s crazy.
And if you can’t afford your architect friend, perhaps he can recommend someone else.
Well, technically it doesn’t have to be a bedroom, I guess; we were contemplating making it into a den/office. And I have obviously never hired an architect and have no idea what it will cost, but I am guessing he will be decent to me. But it looks like he does a lot of projects that are much higher-end than what we are contemplating. But we shall see.
Sounds like a fun project.
I only have my general advice that there are three factors involved: price, time and hassle. You generally have to trade off one for another.
I don’t want to discourage you … but would we all please bend our heads in prayer …
"OH LORD, hear our beseeching, cast Your great eyes upon Your mortal subject and grant her the patience of Job, the wherewithall of Caesar and the wisdom of Solomon. Your humble servant is beginning a GREAT and DANGEROUS task that only You, the Most Holy, can so guide her steps to fulfillment. PROTECT her in her desperate need and shun those of the tribe of Bozoness and those who would fly by night.
In the name of the Father, the Son and the Holy Ghost …
Amen …"
Eh, I deal with various immigration authorities for a living. A remodeling project is, I think, not going to be the largest test that my patience has ever had!
I live in a older home and wouldn’t give up my radiators for anything. Love them so much.
We remodeled and the marriage survived. I’ve often said, “if you can make it through that, you’ll never divorce.” But we were living in it and doing a ton of the work ourselves.
Just speaking as a layman, but agree with this. You’ve said you want to keep some of the vintage features of the house, well radiators are definitely a vintage feature. Tune up the boiler, replace the vents on the radiators, maybe have new covers built for them (old busted radiator covers are definitely an eyesore, admittedly). Steam or hot water heat is just so much more comfortable than forced air IMO. In terms of air quality, forced air might even be worse for those lungs of yours. It’s drier for sure. Filtration can also be done separately.
And, save yourself a bunch of money on new HVAC and ductwork.
I grew up in a NW side bungalow. Most of the ones I’ve seen are solid as a rock. Which is a good thing. What general neighborhood will you be in? (Just curious.)
We just did something similar. We decided where we wanted to live. Our options were to either build new, buy something that had been rehabbed, or rehab ourselves. The problem with buying something already rehabbed, is that it will not be done to your preferences, and you can’t guarantee the quality.
We found a very solid split-level on a great lot in a perfect location in the western burbs. IMO it is hard to beat optimal location. We bought it as-is. Other than the furnace/water heater/AC, we gutted every single room. Today, in fact, workmen started on the sub-basement - the last remaining room that hasn’t been redone.
On the one hand, it was an incredible pain in the ass. On the other, we now have exactly the house we want in our perfect location, where we expect to remain for a long time. Rehabbing is expensive, but I don’t think we could have built new for less.
Most important, realize that it is a VERY LONG, and VERY CONFUSING process. You can get 3 different quotes, and they will be all over the map. Moreover, they won’t assess the project identically, so you can’t easily compare them. And they may not break out individual costs, so you can’t see where your money is being spent or where the savings are.
So approach the bidding process as an education. Have the contractors educate you as to what will work, and how much it can cost. Then you can use what contractor A says to negotiate with B, and so on. The contracting/negotiating process is protracted, with a lot of back and forth. And no matter how careful you are, surprises will arise. And expect that YOU to have to pay for them!
Another thing to decide is whether you go with a single design/build firm, or piece it out to different contractors. The first will likely cost more, but could be an easier process. Realize, however, that you can pay top dollar for a highly recommended contractor, and you STILL have to keep on the workmen to inspect the job daily and insist on compliance with your wishes.
Realize that the best of schedules will be only “guidelines,” so prepare to be flexible. Don’t be surprised if contractors fail to even return your calls, or inspect the job and never submit a quote.
See how much of the project can be staged. Maybe do the first third this year, and then the remaining 2/3 over the next 2 yrs.
Get a clear idea of what needs to be done in what order. For example, we did windows, siding, and landscaping. What order would you do those in? Do you know how long it takes to order windows?
At some point, you just have to decide that you are close enough to a decision you can live with, and you have to pull the trigger. Otherwise, you’ll spend the rest of your live negotiating with contractors, and never get the work done.
I’d strongly recommend asking neighbors and friends for recommendations. Someone who has worked on similar houses in similar neighborhoods will have a good idea of what might arise. And anyone who bids should give you references which you should check.
Also, ask about permitting. There is IMO - a grey area in terms of what absolutely must be permitted and inspected in most jurisdictions. I’m not suggesting that you violate the law. But inspections may cause delay, and will definitely be reflected in your assessments.
Happy to share any other thoughts. Have no doubt, it will be a horribly expensive pain in the ass. But if you love the location and bones of the house, and can afford the $, you’ll love the outcome in the long run!