What's the motivation behind the expansion?

A trash compactor may fit your needs.

Some families use two full size dishwashers. The drawer dishwashers are small and ideal for small, very neat families.

In some ways it depends on if you are messy because you are very busy, or messy because of procrastination, forgetfulness or just don't care. One of my sisters had four of her five children involved in year round sports and spent a few years constantly driving to games and practices and her house was very messy. She was crazy busy. Now, things are better. However, if your dishwasher doesn't get turned on because no one bothered to put the dishes in and hit the start button - that problem will not be solved by a second dishwasher. I won't lecture on simple messiness because it is hardly a big moral problem - unless the health and even sanity of others in the family are affected - then "we are who we are" doesn't work. So, you need to decide whether it is a lifestyle trade off - busy, active family, or procrastination, forgetfulness - maybe I should see a psychologist problem. I say that because I have a couple of children with diagnosed disorders that include short term / working memory problems and they really have had to make neatness a priority for their own well being.

Many are using drawers for lower cabinetry instead of traditional cabinets. I could see a nice large drawer being a good place for breads. A pull out cabinet that contains room for two trash wastebaskets close to the sink is a good idea - but trash should be taken out nearly every night to reduce concern with critters. A designated recycling center, perhaps in the mudroom or garage can take pressure off the kitchen. Two dishwashers if needed. A pantry room if possible, or a row of pantry cabinets - it is easier to put things away if they are all headed to the same place.

Consider a different place for mail altogether - separate from the kitchen. Sort mail every day right away when you bring it in and have a paper recycling basket near this area. Important mail goes into another basket.

Hiring someone to clean every week or two could work in your situation.

LOL. This is a great challenge! Can you post your floor plan?

Stainless steel cabinets, concrete counters, tile floors with epoxy grout. And a floor drain. Hook up a hose to the sink and spray it all down every night, just like a dairy barn.

Or, raise children. Not wolves.

These are some judgmental people. Well my family is messy also. I'm about to go through a whole house renovation myself. I looked around to see where the clutter was and what was in the clutter. Garbage is a big issue for us so I'm installing a trash compactor and pull out under sink drawers for daily recycle. Also vertical storage is key. My problem is things don't have an actual home in my house. They just get put away in any open space. That will end with this renovation. Go through and think of how you will actually live in your space and design based on those needs. Not what's trendy.

When we redesigned my kitchen I kept in mind that one of the things that never worked well for us was that open surfaces attracted clutter. Mail, school papers, newpapers, backpacks, purses, stacks of coupons, etc, etc. We had a peninsula that was just an open surface that was often the most likely drop off place for junk when entering the house, as well as a fair amount of counter space along a back wall that was not useful for food prep. So when we redesigned, we moved the sink to the peninsula - creating a useful area that doesn't attract "stuff" so easily since the area now has another dedicated use (and since anything left there likely will get wet), and we eliminated most of the back counter by relocating the fridge and replacing some of the cabinetry with floor-to-ceiling pantry with pullouts - so increasing storage while decreasing open areas to attract clutter. Now I have a small landing area on one side of fridge that is where our mail goes as well as extra keys, bowl of change, phone (landline), cell charger, and misc papers - by keeping the area for this stuff small, I must keep the pile of clutter small! Moving the sink left us with a nice long uninterrupted counter in the kitchen for workspace, and because of its location it no longer attracts stuff so easily. Also consider placement of things ... like our bread drawer is under our knife drawer with cutting boards and toaster oven nearby, and it is easy to unload the dishwasher because all the cabinets are nearby and easily reachable when dishwasher is open.

Much of keeping things clean is discipline, time, and making it a priority, but if you set up your space properly, it can help you with your goals. The other half is creating habits that work for you - for me, it's to go through the mail as it enters the house, immmediately chuck a good deal into the recycling bin that lives in our mudroom closet adjacent to kitchen, put rest in my husband's box or in mine (in the small landing area I mentioned earlier). When papers stack up you have to find the time to go through them. Be ruthless in throwing things away, though this is a hard one I admit.

Some of the messiest kitchens I've seen belong to people appear (to me) to have some issues with ADD/ADHD, as well. But others just belong to people that have very busy lives and other priorities. Most kitchens won't look magazine ready most of the time, as they are working, functional spaces.

Even the best most ingenious design can't help without good daily habits and routines. When kids were younger, our routine was to empty the dishwasher first thing in the morning while making the coffee. If the dishwasher is full of clean dishes, people will just stack dirty dishes on the counter or in the sink. If emptying the dishwasher seems like a dreaded chore, consider if you have too many dishes and glasses in your cupboards. Cull them down to only what fits neatly and the chore goes much faster.

Take the trash out once a day on your way to work. Make it a part of your habit so it's ingrained. Like full dishwashers, people tend to drop trash all over the house if the trash can is overflowing. If you make a lot of trash, take it out twice a day - morning and after dinner.

Clean up after dinner. Wash any pots and pans that won't fit in the dishwasher. Walk through the house and collect any dishes that haven't made their way back to the kitchen. Set the dishwasher on automatic to start around bedtime. Wipe down the kitchen counters and dry out the sink. A clean kitchen sends a psychological message to your family and they may be less apt to snack at night and leave that last glass in the sink. Start over in the morning with emptying the dishwasher and taking out the trash...

Sort mail at the door, toss junk away immediately, and have a basket for anything that needs attention. Sign homework papers and school notices and put them back in your child's backpack. Keep the backpacks near the door, not in the kitchen, if you can.

Bread: after living in a crappy rental that had a horrible mouse problem, I got into the habit of storing the bread in the refrigerator. Yes I know that's not ideal for bread, but it beats having mice! There's nothing like a mouse infestation to teach you to clean every last crumb off your kitchen counters, load the dishwasher, take out the trash, put away the food each and every night before bed!!!