Hi Dgr,
To allow the left door to open completely, this model needs some extra space on the left side. When positioned flush against a wall, the door may not open all the way, making it more difficult to access certain areas inside the refrigerator.
For exact clearance measurements, please review the Product Specification Sheet:
https://images.samsung.com/is/content/samsung/p6pim/us/rf25c5551sr-aa/specsheet/us-specsheet-rf25c5551sr-aa-550360024.pdf
We also recommend having the refrigerator professionally installed to help ensure proper placement and required clearances are met.
Your trust in Samsung means a great deal to us.
Nicole
Samsung Care