We did something similar, but on the cheap end and over a few years. Our attic was technically finished but was a disaster. We live in a 1920 bungalow.

1. Installed mini splits throughout the entire house, including the attic. $12K for everything, IIRC

2. Put in a staircase. There was an old staircase to the attic but it was a deathtrap ladder. $6K

3. Redid the attic bathroom. Gutted the old bathroom, knocked down a wall to expand, reinforced joists. Existing plumbing was present, but got new electrical, new toilet, nice glass enclosed shower, marble sinks, etc. $13K

4. New attic windows (wood). $6K

5. Gut remaining attic, new drywall, some electrical work. We didn’t add more walls - just opened the space to make it a big master. $12K

Wow, this seems much cheaper than I was expecting.

We are in a 1 story Cape Cod with an unfinished attic. I had a GC come through and estimate 200-250k to finish the attic and put a full bathroom and 2 bedrooms up there.

Who are you going through for quotes? I went with a big design and build firm in Arlington that specializes in gut remodeling. So I can see how they went big on the estimate. But this is definitely something a handyman can't handle if I need structural work done as well

much will depend on how hard it will be to extend your current heating/cooling system. You could consider putting in mini splits if it would be too complicated. It is not clear how large the space is, but I would think about 40k. The 90k someone quoted is crazy. You will surely find someone happy to charge you that much but you can certainly get it done for less. I would also suggest that you consider splitting the job in tasks and hiring the trades yourself separately if you are in no rush to get it done. It will be cheaper, but it will also take longer and you will be in charge of figuring out any hiccups along the way rather than a GC.

OP, I got two quotes for something similar. We already put the a full staircase in. Both were between 65-70K.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

Get several quotes. I am considering the same and hiring a carpenter for stairs, my electrician for wiring, adding vents for existing ac (system can handle additional load) and a handyman for insulation, drywall and refinish pine floor. I hope this would be no more than 20k.

No way.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

Get several quotes. I am considering the same and hiring a carpenter for stairs, my electrician for wiring, adding vents for existing ac (system can handle additional load) and a handyman for insulation, drywall and refinish pine floor. I hope this would be no more than 20k.

This is a project that will need permits. You will need to hire someone to draw plans and get them approved with wherever you live. Do not try this without permits.

And the existing attic space will have to be brought up to code - ceiling/ head heights, minimum insulation per code that might lower the ceiling height depending on where you live.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

Get several quotes. I am considering the same and hiring a carpenter for stairs, my electrician for wiring, adding vents for existing ac (system can handle additional load) and a handyman for insulation, drywall and refinish pine floor. I hope this would be no more than 20k.

This is a project that will need permits. You will need to hire someone to draw plans and get them approved with wherever you live. Do not try this without permits.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

Get several quotes. I am considering the same and hiring a carpenter for stairs, my electrician for wiring, adding vents for existing ac (system can handle additional load) and a handyman for insulation, drywall and refinish pine floor. I hope this would be no more than 20k.

I had an unfinished walk up attic in my previous house that we finished. There were already stairs to it and we added kneewalls, insulated the ceiling, added 2 skylights, drywalled, and added recessed can lights and electrical outlets and it was $20k 10 years ago.

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

What type of professional did this for you?

Not OP, but a structural engineer will be able to determine this.

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

What type of professional did this for you?

Anonymous wrote:

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

Get several quotes. I am considering the same and hiring a carpenter for stairs, my electrician for wiring, adding vents for existing ac (system can handle additional load) and a handyman for insulation, drywall and refinish pine floor. I hope this would be no more than 20k.

Anonymous wrote:The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

Had someone check the joists, they're sufficient. And yes, as long as we do zig-zag on the stairs we can get 36" across. But man I didn't realize it would be that much, we may have to rethink this project.

The stair needs to be a minimum of 36" per code. Do you have that width in the closet on the second floor? Also - you need to make sure that the attic joists are sufficient to carry the loads for a living space. Many attics were built just to accomodate light loads for storage. That said, you're probably looking at $40k to $50k.

That sounds super expensive. Maybe 90k?

We're looking to add space in the existing footprint of our home. We have a sloped attic that runs the length of the house, with about 10 feet wide in the middle that's high enough for just about anyone to stand up and walk around.

We'd love to split the space: half for living, half for continued storage (all our crap is up there now.) We have pull-down stairs, so figuring costs as follows:

Use the space in hallway and linen closet to build real stairs.
Insulate the attic.
Heat and cool the space.
Drywall and carpet.
Optional: cut another small window so there's light on both sides

Any idea how big of a project this would be, and what we could expect to pay?