26 inches of clearance is fine IF you pay attention to the arrangement of the units and the electric/water/discharge/venting. The hinges of the units should be such that, with both doors open, you can transfer the wet clothes into the dryer. Make sure that all hoses etc. are recessed into the walls to allow the units to be "fully back against the wall". Having the water shut-offs located where they can be accessed without having to move the washer is a good idea. A water emergency is terrible if you're not strong enough to move the (fully loaded) washer.

Looks too cramped for me. You won't get 26 inches, 24 to 25 if the ductwork and hoses are recessed. If you choose a front load washer, you will need room for the door to swing open completely. I looked up some Samsung machines and the marketing info said they were designed for a 40 inch install depth. When the door is open all the way, the washer is 55 inches deep. If you do not have the space to widen that area, I suggest stacking the units and placing then lengthwise with the space in the corner

Hi lyndee, I'm afraid the walls and utilities are already in place so no possibility of widening or shifting the appliances. There will be approx 11" left infront of the door when its fully open. It just means that you can not walk around someone if they are doing laundry. Was looking at the GE front loads