I'm in the planning stages but have put tons of thought into this. Hopefully I won't have to tweak it too much when I do the framing walkthrough. (You really should walk though the framed house before finalizing the locations.) No Christmas package (don't decorate for holidays) or intercom. Outlets at a few locations specifically for nighlights (in bathrooms and in hallways) so we don't have to flip on the overhead lights in order to use the facilities in the middle of the night. Switch for the bathroom fan between the toilet and the vanity (instead of with the other switches near the door) so that it is accessible from the toilet and standing in front of the vanity. Duplex outlets near the TV area. Duplex outlet mounted higher on the wall than normal for the main phone area which will be a nich in the wall. Duplex outlets to either side of all potential bed headboards. Oulets dedicated for cell phone charging in an elevated nich. Duplex outlet, tv cable (for internet) and phone (for fax) anywhere that I plan to (or even might) have a computer. Outlet immediately beside the loft railing in case we ever want to put lights across the railing we can plug them in without a tripping hazzard. Although we probably won't need them, I am putting one oulet just inside each WIC. In my workshop, I'll put an outlet 5' high so that I can put a shelf under it to hold a small radio and clock but still be able to put tables or work space under it. Outlets closer together than Code requires so that it's more convenient. Switches for a room at EVERY entrance into that room. (Our current house doesn't have switches at every entrance and it's a pain.) We will have a small vestibule (for guest entry) and small mudroom for our entry from the garden that are beside each other. Their lights will be on the same switch so that when we walk from outside, into the mudroom, into the entry (from interior access) and then finially into the main house we don't have to flip lights on and off every few steps. Just once when we enter the mudroom and again when we enter the main house. Don't forget electrical service for any undercabinet lights. There are past threads about outlets that are mounted so that they are accessible from inside cabinet drawers so that clothing irons or hairdryers can be left plugged in all of the time and stored in the drawers. I'm considering that, too. In a similar manner, outlet inside of mixer lifter kitchen cabinet for mixer. Outlets and switch for pendant lights on the kitchen island. Outlet for microwave that will be raised above countertop height. Exterior grade outlets at multiple places outside that are easily accessible from the porch and patio areas (not for Christmas lights). Outlet at attic access incase I need to plug in a light there since we will have minimal lighting there.

Lots of good suggestions have already been posted. Here are a couple I don't think anyone has mentioned... Lights in our walk-in closets will be wired to door switches so that the light comes on automatically when you open the door and goes out automatically when you close the door - like a refrigerator light. I'm hoping this set-up will also help me train DH to CLOSE his closet door instead of leaving it standing open all the time! Several outlets in the soffits way around the house for plugging in Christmas lights - all are wired to a single switch for ease in turning lights on/off. Extra lights in our stick-built attic space with a switch by the access door so we don't have to use flashlights to find stuff stored up there. Everyplace I've ever lived had one light in the attic at most. Even with it on, the thing you're looking for is always in some other corner that is dark. Mirror defoggers in the bathrooms (a very inexpensive luxury!) Outdoor lights specially positioned for reading when one is sitting on our porch swing. A floodlight positioned to shine up and into the stained glass window that is in our the stairwell so we can enjoy it at night. Lots of extra electrical outlets around the exterior of the house.

We installed 6 in our kitchen last year. Each has 2 regular outlets, 2 USB, and 1 USB-c. All the usb are in between the 2 3-prongs. It was an up charge but i don’t remember how much. Overall I’m pleased to have them but would not do the ones on island again (no need — guests either bring the whole charging thing or nothing, no one carries around just the wire. Also I didn’t pick the ones I have. I asked for Lutron brand but they installed something cheaper. It’s fine so far but the spacing is such that I cannot use the usb AND a 3-prong plug at the same time. Maybe it’s by design to avoid overcharge but it’s annoying.

Apart from the code requirements & possible updating of wiring, you will need a space/area of roughly 3" wide to fit an electrical box. That can be achieved by locating it on the side of an end-of-run cabinet, behind a drawer, if you have one in that location. Of course that will also depend on how deep the drawer is. You can also add on a 3" filler or column box somewhere in the island design. This can be between cabinets or on the end of a run. I do this often when a peninsula has a DW at the very end of the run. I place the 3" column box at the end & that's where the electrical box is placed. Bring the wiring up from the basement or crawl space into the the filler/column box or at the back of the drawer cabinet. The fact that you have a finished basement is unfortunate as there is no other way to run wiring to the island. You can not just run it along the floor. Now, what has been pointed out is that building code requires certain things that you really should consult an Electrician about. Unless you are familiar with building code & electrical, this is not a DIY project. Leave it to the certified professionals.