Can you scan the plans in as bigger files? I zoomed to 400 and had trouble working them out.

It is also best to put the plans in the post. I'm sure you will get help after that.

Thanks. I tried to do both of those things, but I'll keep trying ! :)

It looks like you are not using the squares at the same scale consistently. For a schematic drawing like this you can use 2 squares per foot (each = 6") which = 1/8 scale.

For more detailed drawings I would make 4 squares per foot (each = 3") which = 1/4 scale.

You need to take into account wall thickness even at this stage. Standard construction interior walls are 4-1/2" thick, walls with pipes or ducts may be 6" or more.

I know that sounds like work but inches can count.

Right now I see areas that if you are using 1 square = 1 foot you are way undersized in allowances.

I lose the detail when I expand the photos so I can�t see everything but some things I would think about.

Is your foundation 30x40? Exterior measurement?

A door between your mud room and kitchen.
A coat closet in your entry way.
Do you guys watch TV? Where would you put the TV?
I would think about putting the w/d upstairs. Hauling laundry for a family of 5 up and down the stairs is a lot of work.
You may not be able to span that much space with your joists, without major expense (kitchen and LR).
I would turn the other closets into walk in�s, you can never have enough closet space.
That upstairs hall makes me feel like the walls are closing in. How wide do you have it planned?

A box is not necessarily cheap. Long span I-joist are costly.

Framing should be in multiples of 16" or 24" to save on lumber. (In reality 4'). E.g. your rooms should be close to 12x16, 16x16, 20x24 etc. You need to plan wet walls for plumbing and chase-ways to run ductwork. You absolutely can not run plumbing in exterior walls. You need support walls. Everything you pay for is per sq ft. So simple box and not so simple box may be identical in price. You do pay extra for bumpouts for foundation (per corner). But not that much.

My neighbor has house that some one build using 41x41 "plan", it took another 100k to rework it into livable space. And now he has lolly column in the middle of kitchen island, to support second story. Good luck hiding that one.

Learn on mistakes of others and not yours.

Thank y'all! This is exactly the kind of things I need to know! And that I had no idea of. So is 30 x 40 a workable plan, or do I need to completely change it?

I have to respectfully disagree with some of what shifrbv writes.

1) Yes, long span joists are costly, but a rectangular box is still the least expensive shape to build. I do agree with shifrbv tho that you appear to be going overboard on the "open floor plan" idea. Some interior walls that could also serve as support walls for the second floor would reduce your costs significantly by allowing you to use much smaller joists. And, some interior walls would make your home much more liveable. As it is now, your downstairs lacks any areas where a person could have a little bit of privacy or a couple could hold a quiet private conversation. Imagine adults trying to visit in the great room while a bunch of kids play in the playroom? Or part of the family trying to watch TV while someone in the kitchen is using the blender? Total chaos! Too much openness can be a very bad thing. Studies have even shown that productivity in the workplace is significantly lower in "open plan" offices as compared to traditional offices with walls separating offices. I think it is better to have a nice mix of open spaces and some "quiet niches."

2) Framing in multiples of 16" or 24" to save on lumber really doesn't save all that much. No matter how carefully, you design your exterior walls to perfectly fit 4ft wide sheets of plywood and/or OSB, the interior walls WON'T perfectly fit 4ft wide sheets of drywall so you wind up wasting drywall. Size your home to fit drywall sheets, and you waste exterior plywood/OSB. Bottom line, size your home to fit your needs, not the standard dimensions of lumber.

3) Yes, you do pay extra for bumpouts. And the extra cost is not just for the foundation. Bumpouts force a more complicated roof line - which is more costly to build. Plus, bumpouts result in a lower ratio of "exterior surface" to "interior square footage" so your cost per square foot goes up. Not saying you shouldn't have any bumpouts. Appropriately used, bumpouts lend style and allow you to design a more elegant home...but they do come at a price.

4) The statement that "You absolutely cannot run plumbing in exterior walls" is not necessarily true. It depends on how cold it gets where you live and how much insulation you're willing to wrap around the plumbing. Here in central Texas where the temp drops below 32F all of about two dozen nights per year and it almost never stays below freezing for more than about 24 hours, it is actually quite common to run plumbing lines through exterior walls.

I agree with bevangel on the plumbing thing. While it isn't recommended to have plumbing in exterior walls, it's definitely possible. We live in northwestern ontario where it's freezing at least 6 months out of the year, and we currently have almost all of our plumbing in exterior walls.

Overall the plan looks alright, but you'll need to draw a more detailed drawing with wall thickness, etc. to get a better idea.

I can't really tell your scale, but I think it is about 1 square for 2 feet.

If that is the case, you have some very oddly sized master closets that will waste a lot of space.
Additionally, it will be difficult to get furniture upstairs, as anything long will run into the exterior wall (front).

Generally speaking you'll want your doors to open against a wall, rather than against air (in bedrooms 1 and 3, they should be reversed. I'd also switch the location of the closets of bedrooms 2 and 3.)

Oddly, while it doesn't necessarily make sense to plan your space to lumber dimensions, it can make sense to plan your flooring to flooring dimensions. Most carpet rolls have a 12 dimension, for example. If you can get your accessory bedrooms to have a 12' dimension, it is better in this sense...

And, I am concerned with where you will place your plumbing stack for the upstairs hall bathroom. But, it is difficult to tell, for the small size of the pictures, as mentioned before.

Will there be a basement? (if not, don't forget to plan for the space under the stairs). What about a garage?

a possibility ...