Here's an informative thread that you might appreciate. It was started in 2012 and has been bookmarked over 150 times, which gives you some idea how helpful people find it to be!

http://ths.gardenweb.com/discussions/2286771/small-things-that-get-forgotten

towel warming drawer for the bathroom. have had for 19 years. Thermidor had a special TWD designation when we built in 1997. LOVE A TOASTY TOWEL! New house will have an "outdoor" (wet rated) warming drawer to keep towels toasty in master.

Omelet...TY..I just bookmarked it as well. How can you tell how many times it has been bookmarked? Curious.

Never mind...just realized there is a #

Thanks ILoveRed - I was just going to answer but see that you've got it!

Hot/cold water bibs in garage. More outlets than standard/code.

Central vacuum. Our current home for the past 20 years has one, and we plan for a Vacuflo with Hide-a-Hose for our new home. I have been very happy with our current central vac, but anticipate the same vacuum with Hide-A-Hose in our new home will be even better.

Many items are 'broad stroke' items, such as lay-out and land, as compared to details. We certainly put a lot of thought into the land, orientation, construction, floor plan, etc.

As for more detailed items, #1 has to be two sinks in the kitchen. With two cooks, it is SO nice!

In 60+ years, I've never lived in a fully insulated house before. The comfort level is amazing, aside from the energy savings. We used PEX plumbing using a 'home run' system. It's the first house I've ever lived in where all of the plumbing worked well, all of the time. No slow drains. No problem taking a shower when someone else in the house uses the water. I also went overboard on electrical- many outlets, all 20 amp, so there's never an issue.

Our house is full of small details that we could certainly live without, but they add a lot of enjoyment. I used antique doors, doorknobs, and backplates throughout. Antique light fixtures as well. Even the pulls in the kitchen are re-purposed antique typesetting tray handles. The floors are reclaimed pine from a 120 year-old textile mill. The kitchen ceiling is old-fashioned tin. I did all of my own work, so everything you see in the house is custom. I made my own trim and moldings, so they are unique as well.

Some of these might be obvious or previously mentioned, but sometimes we forget the obvious.

Outlets in bathroom drawers and linen closets. With toothbrushes, razors, and water picks to charge it keeps me from having to leave clutter out on the counter. We also put a floor outlet in the living room to plug in a lamp and the laptop when needed. We added an outlet outside by the roof to plug in Christmas lights. We put an outlet in the master closet to plug in the iron. I guess we put a lot of thought into outlets.

A bench in the master shower for shaving legs.

We ditched the formal dinning for a larger eat in kitchen area. It still fits an 8 foot farmhouse table that can expand to 10 feet and I feel it saves a lot of square feet. I never really got the need to have multiple eating areas.

Walk in pantry... just do it. With he space saved from ditching the dinning room we were able to add a walk in pantry and mudroom. We use those everyday vs a dinning room that would get used a handful of times a year.

- Hot/cold outdoor shower. It was just a whim but it's surprising how much we enjoy it.

- Instant hot water dispenser. Quickly boil water, cup of tea, instant oatmeal, soup, soak greasy pans/utensils, etc.

- hose bibs on every corner of the house.

- Closet light jamb switches. Light comes on when the door opens. We have a problem with turning lights off so I love it.

- Whole house audio system with speakers in the main rooms and porches. Great for parties.

- Wide enough garage so each vehicle's doors and be completely open without hitting.

This may date me but when we built our first house in '86 we almost didn't put in a microwave. Couldn't get along without one now.

And in our current house which we built in '08 we put in a beverage fridge in the kitchen. Love it and it makes for so much more room in the regular fridge!

bathrooms: a lot of counter space next to the basin is incredibly useful.
so is a bench in the shower. storage must not be neglected. space must not be neglected (its a house, not a public bath, size and planning are important)
include at least one entrance allowing easy access for disabled or aged people.
pay attention to window positioning, regarding the usage of the room and the view the window lets in/out. Also pay attention to lighting of internal rooms/areas
have a guest bathroom near to some sort of storage for coats, shoes, bags, etc.

picture living in the house. do a mental "walk-through" from the entrance to the property, imagining yourself getting back from work, shopping, etc or your kids getting back from school, and proceeding through the house as you usually would. picture walking through as a guest, child, picture walking through in the dark, whatever you deem necessary, and you will notice what aspects cause inconvenience/ can be improved.
hypothetical and exaggerated example, you generally get back from work, get a coffee, get a book, and head to the living room, but the design has the kitchen, library and living room in the furthest corners from each other...