I can give you my opinion on a few of these points. I've heard, and it stands to reason, that the planks should be laid perpendicular to the joists, giving them a firmer anchor. However, on a heavily travelled hall floor between our entry, kitchen and LR, we laid the t & g planks in the same direction as the joists for aesthetic reasons. They've held up every bit as well as, and have had no more squeaks than, the other floors. They were installed 12 years ago. I think the direction of the floors can change at the thresholds with no aesthetic problem. I've seen planks run both directions relative to the room dimensions. I think if a room is very elongated it looks wrong to have the boards run across the short way. With your 11 x 13 room, the dimensions are similar enough that I think it would look absolutely fine. Not sure with your 12 x 17 room. It probably depends on which wall the doorway is on (long wall or short one), and where the door is within that wall. I've spent way too many hours analyzing this type of thing in the 15 years we've been remodeling our house. The floors are one thing we did right.

Thanks. I know that was a little confusing. I'd post a photo of the layout but the photos are on a computer that is inaccessible right now. Anyway, it sounds like you are both recommending laying the floors in the same direction as existing ones(was my instinct, too) despite the thresholds - the opposite of what the builder wants to do. My Q about the island was really whether or not it's preferable to have wood planks go parallel to the island. The fireplace is opposite the kitchen (hood and fireplace face each other at end of a "great room". and the island is between the two. Wood can either be parallel to the island or to the length of the room leading to fireplace, but not both. Doing the latter also runs the floors the same way as existing. Hope that clarifies somewhat! The thresholds are to adjust for a 3/4" or so difference in floor height. busybme, Good question as to what material we are using. Existing floors are prefinished hardwood, but addition needs to be an engineered product, since it's on a slab. Complicating things are that my existing floors(Mirage) are an unusual width and set of lengths and I really want to match the look. The existing floors also have a microbevel, something i'm not sure I want in a kitchen. I hear it's hard to match old prefinished to new, since the colors will be off after a few years. The answer seems to be to put in site finished engineered floors and stain both floors to match. Still not sure what to do about matching the planks for size and bevel, though.

Where are the windows in the game room? I'd run the wood lengthwise down the hallway following the same way through the game room (parallel to your "attic storage" wall) and curved hall.

Can you show us where the doors are on each wall. It is hard to visualize how you access each room. My guts feel right now is that if the laundry has its own room with a door closed and there is no way to walk directly from the leaving room to the hallway, I would put the wood floor the same direction as the hallway. I don't know the dimension of your hallway but you might end-up with many partial planks to fit the angles when you get close to the corners. I also believe that your brain might want to walk the direction the planks are laid out if the space is long and narrow. It think the brain would not have problem with a 0 or 90 or 45 degrees but it might have trouble to deal with other odd angles.