You have verified that the lower level of the house/foundation can support the loading for a finished second floor?

@millworkman Yes, I'm working with a structural engineer to make sure all the load is transfered correctly down to the foundation.

@User The pitch of the roof is very steep fortunately so most of the game room is 8' ceilings. The shed dormer will slant from 8' down to 7'. The bedroom area has at least 50% of 7' ceiling height. There are egress windows in the two dormers. Not sure how we would add additional natural light besides adding sky lights, which I hear are problematic for leaks.

The rise of the stairs is 120" from floor to floor and we're planning on a total 150" run based on 7.5" rise and 10" run per step.

A quality skylight installed properly doesn't leak. We had one in our previous house that DH installed (to replace an old one) and it didn't leak at all during the 16 years we lived there and we have plenty of rain and high winds. Certainly a pro should be able to have as good or better results than even an expert DIYer. Have you thought about how you're going to get plumbing and HVAC up there? Is your current HVAC system going to be able to serve the additional load?

Show the 5' high kneewalls and the sloped ceilings up to the 8' ceiling height, because that changes your footprint of rooms. Show areas where HVAC will interfere (chases, etc). Verify whether sistering or building a new floor plane above to support the floor will not affect stair rise.

Other than that, the layout is not very good. You are not limited to walls having to bear over walls downstairs. And, I am very surprised that with this layout of hip roof, on a ranch, is stick built and not trusses. A stick-built roof of this layout would have some beams and posts to account for.

I think the bedroom, closet and bath space needs some more work. Consider bringing the closet into the bedroom entry area and enlarging the bathroom with some of the closet space shown in your drawing.  Perhaps have a separate closet with door and hallway to the bathroom. As is, that bedroom seems disproportionately large compared to the bathroom.

Skylights should be easy to add in a steeply pitched roof as many of the leaks occur with placement in low pitch roofs.

We’re planning on a two zone mini split that will come up from the right wall.

@3onthetree What specifically about the layout is not very good? We are primarily limited by where the staircase has to go. I’m open to suggestions for how to better use the space.

Basically when you come up the stair, that is a bottleneck. I can't really make suggestions as I don't know the sloped ceilings, but the bedroom is probably compromised about where a bed can go and where you can walk without hitting your head.

Have you actually talked to a structural engineer, or are you just dreaming? If not, are you able to evaluate structure, measure things, understand about insulation requirements, spans, etc? An attic conversion is a very difficult undertaking in a house that wasn't designed for it.

Who is this bedroom for? Is it to be a new master bedroom? Is that a landing at the top of the stairs with 3 doors? I would prefer to walk up the stairs into an open area. Is it possible on the right of the games room to create a large full wall dormer with clear story windows? If it is for a master bedroom I would consider switching the two areas to create a great master suite. There are a few other changes but till I know who this room is for I will hold off in adding too much at this time.

The three doors at what I assume is the top of the stairs seems claustrophobic and tight. If possible, I'd take more of the bedroom space to make a larger landing with an opening (not a door) to the game room. In my opinion it's never inviting to trek up/down stairs and be greeted by a series of doors rather than an open landing into a living space.

IMO we will wait until you get the proper go ahead for this project . In the meantime who is going to be using this space ? I am not sure why 2 closets . How old is the original house ? When we coverted our attic we had a lot of work to be done before we even becan to plan the space . We did a large dormer to house a abthroom. When we mentioned a sky light we were told if we touchedd the roof it would all have to brought up to code so no skylight .We had our master up there and an office with a really nice sized bathroom.

Thanks everyone for the feedback. I'll try to address all the questions and provide more insight below.

@3onthetree I am working with a structural engineer. We will be sistering 2x8's to all of the existing 2x6 floor joists. We barely have 36" width for the staircase so the staircase will have to be an open design. In order to accommodate that and support the load we'll be putting in a 4x4 post at the top right of the staircase on the floor plan.

@User The roof system is stick framed and the structural engineer and framer have confirmed that the design as-is is workable with some small modifications.

@pricklypearcactus I agree that the three doors at the top of the staircase is less than ideal. I considered having the landing open up to the game room, but we are really wanting the noise isolation between the upstairs and downstairs. We can't full enclose the staircase since we wouldn't have a 36" width after adding an outside wall. Our living area downstairs where the staircase starts is open to the dining and kitchen areas so one of the main benefits of having this upstairs will be to have a play area for our kids that's isolated from the rest of the house.

@Patricia Colwell Consulting @Lorraine Leroux The bedroom will be for our kids. We have a nice master bedroom suite on the downstairs floor (I'm attaching that floor plan). There's an 18" LVL on the right side of the game room so that space can't easily be used. I plan to have an door from the game room to use that as attic space. We may end installing a traditional HVAC instead of a mini-split and in that case, the air handler would also go there.

So, structurally we have everything figured out to make this work. The main question I have is whether we could improve how the space is divided up. Obviously, the staircase is set, but everything else could be moved around for the most part. We mainly want to get a bedroom, bathroom, and game room out of the project. There's not a lot of closet space downstairs, which is part of why we have the larger closets upstairs. I imagine we could use the closet off the game room as an office.

How would you get a games table into the games rooms or anything else into the games room? You have no room to move furniture in or out of that room. And to use it as storage you would have to make sure it will make it up the stairs and be able to be turned. You have created a bottle neck at the top of the stairs with no turning radius to get anything upstairs. Furniture nightmare.

I would create a landing area at the top of the stairs where you have the closet so you can move the bathroom door and create new entrances into the games room and bedroom AND be able to move furniture around when needed. It can be a nice reading nook or study and you can still keep a wall of closets on the same wall you have it on now just a reach in rather than a big walk in.

@Lorraine Leroux Good point about moving furniture in and out of that room. Let me see what I can come up with.

Something like this? The only problem is that we lose closet space for the bedroom.

Put your bedroom closet space into the games room. Make it as deep as you want or a simple reach in or even built ins but use the games room space. Here is a rough of my thoughts so you do not loose bedroom space. It takes all the doors out of the landing completely.

The three doors at what I assume is the top of the stairs seems claustrophobic and tight.

And dangerous.

@Lorraine Leroux Thanks for the suggestion. Below is my next iteration. I was able to maintain the size of the two rooms while still getting a closet attached to the bedroom (I need to check headroom to make sure a door can fit there).

Thoughts on this anyone?

I’d say this is an improvement.

Architecture 101: “walk towards light”. I’d try to get a skylight in the bedroom and bathroom. In my last house I built an attic office and always deeply regretted that I did not put in 6 skylights (I did 0) when I had the attic to the studs.

I like it Aaron. I would however work on the bathroom. The space between toilet and edge of vanity looks really tight. Usually in small bathrooms you put all the fixtures on the wall opposite the door so you have walking room. Also check with your builder on the stair opening needed. You may be able to still put a closet at the end behind the bathroom if you can make the stair opening shorter so you can use that storage space in some capacity.

My sister and I shared an attic bedroom, no games room of course but it was set up with no doors in between the bedroom spaces just a book case it was awesome . Maybe get some feed bacl from the kids . I would never have had agames room next to my kids bedrooms and for sure not on the floor above my bedroom Yo don't mention the sexes or the ages. I do agree the attic is great space for sure in a small house.

Draw yourself a building section, including the new sistered joist height with floor sheathing, to get the exact distance under the roof where the 5' kneewall and 8' ceiling height perimeter is.

@3onthetree Can you show me an example?

That is starting to flow really nice Aaron.

Also, a 2x8 floor joist can only span around 12' (not considering if fastened sufficiently to a sistered 2x6 ceiling joist), so the existing main floor walls and slab become critical in carrying those loads. The attic floor walls do not necessarily have to mirror the main floor walls, like the bedroom wall is proposed, so that might be limiting you in your layout. Also, the toilet is critical to placement so the 3" waste line can connect directly to the main stack within a floor joist space, unless you want soffits on the ceiling below.

None of the current 2x6 or 2x8 floor joists span more than 12’. All 2x6s will have a 2x8 sistered and every other 2x8 will have a 2x8 sistered. We’re adding an LVL along the staircase with a post at the end to support the floor joists after cutting out the staircase.

I understand that upstairs walls do not need to align with downstairs walls. However, the bedroom location is limited by the existing 18” LVL running where the right wall of the game room is. Were there specific layout improvements you had in mind?

I do need to look at the toilet placement again. The floor joists run left-right so with the current toilet placement we may have to run the 3” pipe down the outside wall. Thoughts on that?

Find the 4" main vent stack in the attic going through the roof. Place toilet next to it. With 2x8s you only have 7 1/4" to slope a 3" sanitary pipe to the toilet, which includes the elbow up to the flange. So you are very limited in how far the toilet is away from the vertical connection.

As far as the Bedroom wall, I know there is an LVL that you are using to delineate the Game Room wall. But the whole landing area is just too notchy and complicated, as is the rest of plan. Simple is better and more flexible. Have yet to indicate where the slope of the ceiling will hit your head.

@3onthetree I’m gonna have to work on the bathroom. I get that you don’t like the plan, but I haven’t heard any specific suggestions for improvement.

Here's my latest floor plan for anyone interested. I reworked the bathroom to move the toilet near the wall where the drain pipe will need to be dropped.

This is a very important criteria (5th mention by me) used which will determine a layout under the roof of an attic:

I don’t have the capability of creating a side view like that. The game room area will all be 8’. I’ve labeled the knee wall heights on the outside walls. In the bedroom there’s a marker showing where the ceiling reaches 7’.

If I use that marker (bubbled in GREEN), then your 7'-0" ceiling height is shown similar to the RED dashed line, with another at 8'-0" guesstimated. You can physically measure this conceptual 7'-0" line by getting in the attic and get a dimension to the exterior walls.

If you look at the shaded YELLOW in the bedroom and bathroom, that is approximately the area that is usable (to 6'-8" or so ceiling height). So, conflicts with a usable bedroom without any dormer access, and possibly an unusable toilet placement. Understand the 5' kneewall height is the extent that your assessment would consider the square footage, as you can actually use a short height area to place a dresser or have a closet, but for walkable circulation it is obviously too short.

Thanks for drawing this out. The collar ties for the bedroom dormer are 7’ 2” and are about 1.5’ wide. Won’t have any problem accessing it from the bedroom. We’re planning to have the front wall of the game room dormer at 8’ so that the ceiling there will all be 8’. I need to verify the ceiling height above the toilet, but I think there should be plenty of headroom there.