Plan it out carefully, headroom would be a concern.

I avoid treads that are not rectangular in shape.

Some comments just looking at stairs:

• The winder treads are not to code for the U.S. That changes the entire stair layout.
• I haven't drawn it in section, but the 'U' shape stair in the basement (the 2nd part of the 'U') does not look like it will have the headroom required, and it appears the builder has not drawn a section either to verify that extra turn.
• I would assume with the original stair, that a portion of the Living Room wall was open at the bottom flight (3 treads) to make the room more open and feel larger towards the front entryway. On second thought, looking closer, the strange location of the Pantry and bar cabinet would not have allowed that.
• The porch stoop appears to not be labeled adequately on the drawing for your review. It is drawn as level with the first floor (required to be no lower than 1 1/2" of the top of door threshold). However, I would assume the stoop's "5 risers" label makes it a step down from the front door (making it a total of 6 risers to grade). That qualifies as no more than 7 3/4" from the top of threshold (not the first floor). Some people prefer a "flush" stoop rather than a step, please note it is what you prefer. The 6 risers is important to the next comment.
• The Garage step landing appears to not be labeled adequately on the drawing for your review. It indicates "6 risers" of the flight. However, I would assume the step landing has a step down from the garage door. If so there are then 7 risers total, that makes the garage lower than the front stoop. On a flat lot, that will not jive, on a sloped lot, that is possible. The "top of concrete" on the foundation plan has not been adequately labeled either to confirm.

Other unsolicited comments, just a cursory review:

- It appears this is a common duplex design that is being built as a freestanding detached structure. It might be nice to introduce windows in the Dining Room and Entry, and Walk-In Pantry wall (transom).

- There seems to be some half-baked things here, I am not sure if they have built this plan design yet. Like the chase (which would only be for HVAC) from the basement to the middle of the Loft ("Bonus Room") that can go no where in the floor. Or the lack of beams shown (which also affects HVAC).

Are all the windows upstairs fixed? The sizes make them look like they will not be operable to allow fresh air when the weather is favorable.

Actually the bedroom windows being shown as 48" tall will not meet egress anywhere in the US if they are operable units.

I am in Canada so we must have different codes up here