I rarely write reviews but this game... it did a good job to seriously upset me.
First of all, Build-A-Sim lost Create-A-Style. Sims 3 was a revelation among the releases because it gave player complete control of the creation. With Sims 4 all you get is "choose crap that we've pre-selected for you". No more customisation.
Ok. I will stop here for a second. If you're looking to play just like... well, create dramas and interactions - go ahead and get Sims 4. But personally, I was interested in the storyline as well as design.
Now, talking about build mode... Looking at the whole Sims timeline, I'd say that build mode was taken from Sims 0.5. Seriously. I've been playing Sims since the first one. It was fun. It was intuitive (kinda) from the first minute. After building with Sims 4 I got annoyed within 5 minutes. Again, if you just wanna drag-and-drop - this game is for you. If you want to build everything your way, don't expect it to be even a bit like The Sims 3. You build one wall. Fine. Rise foundation. Fine. Once you create a foundation and put one of pre-selected styles (no, you can't change colour to the one you want)... you won't be able to change it easily. Personally, I haven't found out how to remove the style or apply a new one (a person who played Sims since day one).
Ok. I got over the initial upset about the foundations. Fine. If you change the height of your walls, don't think all the doors will fit in. Only ones dedicated to the height of the wall (if you build high walls you get selection of two doors). Fine. Second floor. Hmm... I didn't like closed floor over the whole floor. I wanted an opening in the floor in the hallway. Removed the floor from the whole room (didn't find how to remove tile-by-tile) and... I wish I haven't. I wasn't allowed to place floor again (only at the floor below).
Oh! Did I mention that camera doesn't have 360 degree rotation? Just 90 degree around. And you can select top view which smoothly transits from 45 degree angle to top (and you think "why on earth can't I rotate in 360 degrees????").
One thing on the good side - you can now move entire house around or room without need to delete it first and move to somewhere else. But thats it. Those beautiful different size walls... Maxis finally realised what people want. Ability to adjust wall height and join different heights. But they never realised the reason for that. You would think "OMG! Finally I will be able to build L-shaped stairs inside the house!!!" forget it because you won't. Actually, the wall size doesn't even make any sense in the game.
And actually I could go on and on, and on about this game. Personally (PERSONALLY!!!) I didn't find anything even a bit interesting. I have more excitement when I go back to Sims 1 every now and then.
Seriously. Biggest Sims flop in the history!