The sun plays a big part in how our flooring looks. When you walk into our house, there is a huge hallway, approx. 9'W x 20" long that leads into the great room. The far wall in the great room is covered with windows, so when you walk in, you see the wall of windows ahead of you. The model of our house had the floor boards going the length of the hallway. We thought it looked like a bowling alley, so we asked that the floor be installed diagonally (with the strong approval of the builder's designer). At night the floor looks gorgeous...the diagonal takes away that long, bowling alley look. However, the daytime is a different story. The light from the wall of windows shines into the house and if you look at the floor, it looks choppy because you see where all the boards end and you also see every defect. Our floor is natural maple, so the edges where the boards meet are very noticeable. You no longer see the long line which I now believe would look better, at least in the daytime. So, sunlight does play a part because it does show every defect. I know tigerwood has a lot of variation so maybe it wouldn't make as much of a difference as it does in our house. So, the point of this entire ramble is to say that where the sunlight hits can be a factor.

I think it depends, actually. In our living room the tongue and groove ceiling and the floor will run the same direction (floor not yet installed). Big room. On our original porch on older part of the house, as in most porches, the tongue and groove runs longways, the floor runs shortway, typical for an older home (though not always). Looking at your drawings, I would run them to the fireplace and I'm assuming that your ceiling is running the same direction. I can feel the movement/energy from top to bottom (fireplace to range), the other direction would feel static to me.

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.

I would go the long way with the hallway and continuous throughout. Having a hallway with the floor the wrong way just looks plain odd. If there is a separate room that is not continuous with that floor, then go the long way with that room. Example, a connecting breezeway with stairs to enter house is longer west to east, but inside the house there is a hallway and room that are longer north to south. You want to go long with the space however it applies. Also the direction you lay LVP does not affect structure, you need a solid base for it anyhow.