Major changes to a 1-1/2 story 20X30

[MushCreek]

I'm thinking about using the plans here for the 20X30, but have a lot of changes I'd like to make. I didn't post in plans support, because I also want feedback on the floor plan, etc, and there's more traffic here. I'm posting a sketch of the floor plan below to help explain. Looking at the plan, the main house is 20X40, and this part would be over a full basement. There are 12X16 wings on each side, one for the parlor, and one for the master BR. Since there is no plumbing in those rooms, I figured I could save money by either putting them on piers, or maybe a crawl space. I don't really need the whole house to be basement. I'm guessing that I would use an LVL of some type to support the parlor opening, which is 15'. This beam would have to support the main roof, the upstairs, and a shed roof over the parlor, so there's quite a bit going on there, although it is a light snow load area (10-15 lbs). I also added a bump-out in the dining area, although I'm not married to that idea- just something I'm trying out. If I do the bump-out, the floor would be cantilevered, rather than complicating the foundation. The master wing has more opportunities for support with the various walls there. As drawn, the eaves on the main house would be 14', with the first floor having 10' ceilings, and about a 3' knee wall upstairs. We probably won't use the upstairs much; actually it's mostly for access to a second floor deck over the back porch (not shown).

Now for all of the questions- Since I haven't bought the plans yet, I don't know if my changes would work with the original design, or have I added on too much stuff? I already figure I'll need a ridge beam since the side walls are taller.

Is the bump-out going to be a big hassle with the cantilever floor?

Do you think the design is inefficient? I know a square house is ideal, and this house has a lot of linear wall for the square footage, but it's a mild climate (SC) and I like the idea of my major rooms having light and ventilation on three sides. I figure the additional $$$ spent on materials will be more than saved in labor. I'm also trying to keep the square footage down for the tax man.

Rather than a more complicated cross gable (which would look prettier) I'm planning on shed roofs over the two wings. The main roof will be 12/12 pitch, and the wings will be 4/12.

Like everyone, I'm on a tight budget, and I have an alternate 800 sq ft box that I can build very cheaply if money fails us, but this design is what I really want!

[MountainDon]

First I just want to comment on the square house thing. I don't know anyone who lives in a square house, that is a larger house than say 14 x 14 or something small. I think it would be a boring or impractical design if it was something like 34x34 (about the same sq ft as your drawing if I did my quick mental math correctly.) One must be happy with the design and if that includes a couple extensions then so be it.

... need time to think now...

[cbc58]

are you looking for feedback on design?  as far as cost is concerned... i would think that anytime you create a "wing" or bumpout, it would add to the cost to build.  imho, i think in a house of this size you should consider going with a smaller master closet.. and maybe being more economical on seldom-used space to free-up daily livable/usable area... but that's just me.   for instance... you could probably just have one bath on the first floor with two accesses and integrate the laundry...

[MushCreek]

A couple things- The wife HAS to have two bathrooms. Period. The big closet gives up some space, since it is a walk-through. If I don't make it walk-through, you have to go all the way around the house w/ laundry. This is our retirement home, so storage space is important, and there's really only the one closet, although I'll rig something up near the laundry area. I enclosed the laundry (probably bi-folds) since it is near the front door. At the top of the page will be a 1-1/2 car garage. I've tried it fully attached, and also with an enclosed breezeway/mudroom, which is what I'll probably go with. SC has enough sloppy weather that it's nice to have the family car accessible without going outside, esp. as we get older. That's the only place the garage can go due to the slope of the land. We have plenty of acreage for outbuildings; in fact, the barn will be the first building built, and it will be bigger than the house.

I did put this up for design feedback, but I'm mostly interested in the feasibility of building this house from the stock 20X30 1-1/2 story designed offered here, or am I better off designing from scratch? We have a 360 degree view, but the best view (mountains) is at the bottom of the drawing, where the kitchen is. The Parlor, Kitchen, and Master BR will all have this view, plus the aforementioned light and ventilation, which is how the design evolved to what it is now. Due to the slope of the land, the basement will be a walk-out, again, at the bottom of the sketch, so the kitchen area will essentially be like the second story in the back. There will be decks and porches out the back, too.

[Onkeludo2]

First, I fully understand the two bath rule...I am the one who instigated it at our house because I like a tidy bath and my wife has too much junk.

For your large openings you can use garage door headers to save cash and engineering.  Keep in mind you may have to upgrade the footers where those point-loads are at the edges of the openings.

Now for my soapbox(es):

If this is a retirement home, put serious thought into designing it for aging-in-place also know as universal design.  This does not have to cost extra money but requires a lot of thought and planning.  36" doorways are best.  All "primary living space" must be on one floor.  Entry to the home should include at least one place that can be made ramp accessible.  Blocking in multiple area of the bath and layout that allows the retrofit of a roll-in shower or a seated tub.  Light switch and outlet heights that vary from what is considered "normal."

Simple home shapes make for easy building.  They also make for easy to detailing for waterproofing and roofing.  More corners make houses more expensive.

Finally, wet walls are your friend.  If there is any way to swap the master bath and master closet and get the laundry located so it shares a a vent stack with the rest of the plumbing, that is a good thing.

I hate to repeat what another member mentioned to me...both you and your wife will be happier if you move up to 24' wide house.  They, of course, were right.  So I have gone back to my 24' wide designs.  You might consider it as well.  Your bump outs would then be more modest and packaging would be easier.

Also, consider moving the "front" bump to one side or the other and make a large porch where the bump is not.

Mike

[MushCreek]

Thanks! The doorways are all 36", and all of our needs would be met on one floor. I've known too many people who couldn't get around their own house after injury or surgery.

I originally drew the main gable 24' wide, while keeping the overall width at 44'. I was afraid I would need really ma$$ive floor joists, or have support columns/walls in the basement. I know 20' is pretty easy to span. As I said, I'm trying to whittle down the square footage as well, since that's what they tax you on. It's interesting that there is no change in the linear feet of wall if you make it 24' (or anything up to 44')

Some good points about the wet walls and the garage door headers. Since there will be a continuous basement wall under the point loads, I figured they would be OK, but I'll have an engineer check my work. I hadn't thought of moving the parlor one way or the other to have a bigger porch (why hadn't I thought of that?) Originally, it was going to be a cross-gable design, so I was going to keep the two wings in line with each other. With a shed roof, it's not really necessary. I had planned for both a front porch and a back porch on the side, but I could move the Parlor closer to the garage, and have a bigger back porch, with just a covered entry for the front door.

This house lacks a 'grand entrance', but due to the slope, it's hard to fit in any entrance. I also wanted it to look like a funky old cottage that may have been added on to over the years. We do very little entertaining except close friends and family, so the outside appearance is secondary. We just want to be comfortable on a small budget.

[John Raabe]

Mush:

I actually think the layout is pretty good. You can tighten things up a bit (back by the bottom of the stairs), but you have identified the major structural changes. You will need beams to carry the loads over the openings (your dotted lines). You will want a local check from an engineer on these and the possible stiffening of the walls that are now not tied with balloon framing all the way to the floor.

I might suggest exploring this with gable roofs over the two additions and a hip over the dining area bay. I expect it would look rather classic.

If you are doing a concrete basement for the main portion I would do a crawlspace at the additions.

[Onkeludo2]

Regarding floor joist sizing.  If you are not adverse to a center beam below the floor joist (I am) you can reduce the depth of the floor joists considerably.  Again, depending on your feeling about posts (I hate them, but they are standard practice on older basements) or a central load-bearing wall, this could be a relatively modest built up beam or a massive but reasonably priced steel I-beam.  You can even hang your joists off a steel beam to avoid the headroom issue but we are starting to get complicated for a text-based explanation...

Mike

[MushCreek]

I planned on having the upstairs mostly on the back (kitchen) side of the house, since I want access to a second floor deck I have planned in the back. I was thinking about making the other end (foyer/laundry/bath) one story, and maybe even go to an 8' ceiling. I was trying to figure out how to connect the two shed roofs with a shed roof there, making a shallow hip roof wrapping around the second story gable. It's easy enough to do, except for trying to connect a garage to it. The shed roof over the parlor will run the full length of the house, making a covered entrance, and a screen porch in the back.

The second floor deck will certainly brace the upper walls at the 10' level, and the lower shed roof sheathing will have considerable skin strength to keep the upper walls from bowing out over the openings, but I'm not sure if they'll buy that without some fancy engineering that I can't afford. It should be enough with a ridge beam and collar ties. The ridge beam can get some intermediate support through to the basement along the way so it doesn't have to be so massive. The left side of the stairwell is on the centerline of the house for that reason. I've also thought about getting quotes on load-bearing attic trusses, since I'm not after a very big room upstairs.

One of my earlier iterations of this design had a shed roof just about all the way around the first floor, like a wrap-around porch with some areas enclosed for living space. But then I realized that very little sunshine would ever get in with all of those porches, so I removed some. I may have an open deck off the back, wrapping around to the porch on the parlor side, and the master BR on the other side. The BR is the east side, so I want to let morning sun in. The parlor is on the west, so I want to shield more sun on that side.