Lots of talk at KBIS 2017 about smaller appliances for downsizing and living small.
This doesn't mean you can't seamlessly integrate your kitchen, you indeed can with a "built-in" microwave and a trim kit in tiny houses
TrimKits USA builds more 24" wide trim kits than all others combined.
In regards to the microwaves, you can get them as small as a .8 cu. ft. Panasonic, model # NN-SD372S.
Check out our web site at: http://www.trimkitsusa.com/pnnsd372seu2420873
We also have 24" microwave trim kits for many other microwaves as well