Our newly remodeled kitchen holds a temperature that averages about 5 degrees cooler than the remainder of the house. The house thermostat is set at 70 degrees, and the kitchen has been as low as 63. The furnace servicemen measured the temperature of the outside wall at 65 degrees. They believe that is a bit cool, even for an outside wall. They increased the furnace fan speed, but it has not helped. I am wondering if the drywall contractors neglected to install insulation before they attached the drywall. Could the lack of insulation on one outside wall and one wall between the kitchen and garage account for the temperature difference? I should add that we are new owners of this house and have no history or way to discovery if this was true of the house before we moved in or had the kitchen remodeled.
I use a Black and Decker Thermal Leak Detector to compare the temperature of the walls around rooms, windows, floors, etc. With it you can determine whether an outside wall in the kitchen is colder than one in another part of the house. Also, you can remove the cover plate on an outlet on a suspected wall and use a flashlight to check for insulation.
Increasing the fan speed is an indication of a not-very good furnace serviceman. Whatever that did, it did it everywhere in the house, so the kitchen would have the same relative temperature.
An energy consultant can help you, and bring an IR camera that can "see" if a wall is insulated. You'll also want to "balance" the vents, which means turning down dampers in overheated rooms. You can sometimes add floor insulation to bring up a particular room's perceived temperature.
The space under your cabinets might be extra cold, as it may be bare floor boards with no finished floor.