Sketch didn't attach.

Having some counterspace on both sides of the range is safer. But adding your scetch would probably make clear what your question is. Is it a jpg file?

Unfortunately, the sketch isn't a jpg; it's a PDF. Basically, the area is L-shaped. Facing the area, from left to right is a dishwasher, then a 24" base cabinet with a sink. I'm closing off the dead corner and just putting a counter there, then to the right is a 12" base cabinet and the range. This is just for my family room, so I don't need a lot of counter space. I only use the kitchen area as a back-up for holidays and parties.

bojaby, do you have a picture that you can share? It would help to see a real example. I've seen some photos of older kitchens with free-standing ranges with no cabinets anywhere and they look fine to me. I also took another look at my range, and it's black with a textured finish, which matches the microwave that will be above it.

And I finally got smart and took a picture of the sketch with my phone. It's attached (twice, sorry). The only difference is that I squared off the sink instead of putting in a corner sink.

Hello---yes, do as your contractor suggests and add the cabinet. That extra counter/storage is a must have in such a small space... Good Luck!
[houzz=]

Rosalie, sorry I don't have a picture as the kitchen is in our summer home and we have not opened it yet this year. From your sketch I can tell that it is a similar situation. I cannot remember if there is a panel on the side of the microwave above the stove or not but if your microwave is black I think it would work either way. If this is a mini-kitchen for convenience I think you have a very useful and efficient plan without an additional base cupboard. Go with your original plan.