Only upgrade the bones of the home or things not easily changed. Developers/Tract Home Builders make the bulk of their money on upgrades and change order.

I regret not splurging on fancier railings/glass for our main staircase. At the time the additional 5k seemed astronomical. Now I realize it was not. I regret not getting landscape lighting, well actually I did ask for it and it wasn't done, I regret not checking more carefully before the landscaping was all done. I regret not getting a fireplace longer than our TV so it was more visually appealing. I regret not choosing an entry chandelier because we are still paralyzed by indecision on this one spot 2.5 years later. I regret getting a kitchen sink that is flat and square. Such a pain to clean.!!

I do not regret getting all drawers in our kitchen. I love it. I also do not regret going with better appliances than I thought we would because I love them all working together. The second oven is a dream I didn't know I had and now can't imagine not having. I do not regret splurging on the master bathroom. Every time I walk in I appreciate it. I also do not regret splurging on a custom live edge vanity in the powder room as it is a well used room by all and every guest we have. I also am super happy we got custom closet organizers in all rooms, even our basement suite, mudroom and laundry. So easy to not do and well worth it to do.

Skip builder upgrades, exactly as @millworkman said. The dollar return is less than 1:1.

Make sure all bathrooms have natural lighting. If not add a window or skylight now if you can.

I do not regret upgrading the front door.

I regret having white windows instead of black although white probably does look best with the style of the home. I had black windows in my old home and miss them. I thought I wanted a change and truly didn't. I can live with the white nonetheless.

I do not regret making the open floor plan model a little less open by making changes to our layout.

I do regret keeping the builder "custom" drywall finishes. I knew I didnt like most of them but wasn't sure which way to go. I ended up paying money to have builtins, columns, plant shelves, etc removed. Some of the fussy finishes I did not include during construction but some I missed or just went with.

def spend money on things you can't change basement windows bonus room plumbing rough-ins 3rd car etc. don't follow trends. think 10 years down the road will you still like blue cabinets? or busy flower tile? etc.

We are in the midst of building and already have some regrets - no matter how much you try it's impossible to get it all right! But we've spend the last few days on electrical. It's not flashy and just added an extra $9000 to our total but it was important that we did all wiring now. Think - plugs for holiday lights, motion sensors in walk in pantry, step lights on dark stairs and hallways etc. We also added in extra lights in closets, and switched plugs outside in 3 areas where we might want party lights. Wiring for tv's, switches on two sides of rooms for convenience. I regret not adding an additional bathroom although we would rarely need it (3 1/2 instead of 4 1/2). Cheap to do now, hard later. We maximized storage - hallway closets were made into walk ins for example. Tried to keep big things classic, not trendy - I agree with the blue cabinets - I LOVE them! But probably won't in 2 years. Pulls, lighting, etc, can all be changed easily and cheaply. Same with paint But cabinets, tile and counters are much harder and more expensive. Good luck!

I agree with the builder upgrades. Only get what you can't do easily later. We did upgrade the cabinets, we had wood flooring installed, etc. But things like nicer faucets, paint, window coverings, etc, we did ourselves after moving in. We saved a lot of money, and got what we really wanted because although he offered many options, not all of them were something I would have picked.

I decided to get everything that I wanted in my home. The only thing I stepped down on was foam insulation for the outer walls but I got it for the roof.

Things we made sure were done ahead and glad we did

blocking in walls for Artwork

grab bars in shower

hand held faucet in shower and tub. Makes cleaning a breeze

floor plugs for lamps

electrical outlets in wall for inside cabinet lighting

hose bibs on all corners of garage

enough exterior lights to see around all exterior

sink in garage

Things we spent money on and wish we hadn't

Skylights in covered patio. They are too small to make that much of a difference.

We are in framing/roofing stage. Already have a couple of regrets, no where for microwave in kitchen, have to go with a drawer microwave in island, or move it to walk in pantry. Custom builder pricing did not include kitchen cabinets to ceiling so that’s an expensive upgrade. We incorrectly assumed we were getting stone up to mantel on interior fireplace, found out no stone included, only a granite surround.
In general our rear elevation is not what we expected. From our veranda to ground level is at least 5, maybe 6 steps, we hoped for 3 max.

Things I love about our new house, to name a few:

*Orientation (front faces about 20 degrees west of north which allows for amazing fews of our farm from the rear and for a ton of natural sunlight into our living spaces)

*Our full basement (about 1/2 of 2700 sf is garage and the rest is a living/tv/game area, bathroom, storm shelter room, DH's office and my junk/craft supply room)

*Our flooring (7.5" engineered white oak in a light/natural finish)

*Our back porches/carport

*DH was a genius in putting a hot/cold water spigot at our basement garage but I wish we had them at every location

*Walk-in pantry - ours is ~7 by 14 and I LOVE, LOVE, LOVE it! It's large enough to house an upright freezer, extra fridge, tons of shelving, and a 6 ft section of upper and lower cabs. I use the counter space for our countertop appliances, the lower cabs for large appliances like crockpots, pressure cooker, griddle, etc. and my uppers have glass doors so I have my china and crystal stored there. It's amazing :)

Misses:

*Windows - wish we'd done more research on the windows the builder typically uses, which are vinyl. We are already having trouble with 3-4 windows not latching correctly :/

*Size - after living in pretty cramped conditions for 2.5 years with 4 kids, one would think I'd relish all the space (3200ish sf plus the full basement) but 2500 would've been about right.

*White exterior - we live on a farm and I'm already semi-regretting our white board and batten because of all the dirt and bugs. I foresee having to hose the house off a couple of times a year...ugh. Wish we'd gone darker but I had my heart set on a white farmhouse ;)

Haven't gotten a custom house built (yet!!) but think super hard about the electrics and other wiring needs. So easy now, so hard later. If you live near people I’d highly recommend running low voltage to windows you want to install blinds/curtains on. I put in automatic curtains (plugged into an outlet) on a giant living room bay window I have and it was the best $$$ I’ve ever spent. They open and close automatically everyday and it’s honestly eliminated 5 minutes of frustration from my day, everyday, forever, as operating them previously involved climbing on my couch. I now wish every window had automatic blinds but am limited by nearby plugs...

Think "inside the walls" - wiring, insulation, and plumbing. Extra outlets in every room and several on the exterior. Hose bibs (exterior spigots), at least one at each end of the house, both front and rear. Sloped floor to drain in the garage if you live in snow country. Get the "softener loop", inexpensive now - costly to add later. Sprayed-in foam insulation in all exterior walls (garage too), because energy costs will always rise.