The term 'Architectural Add-Ons' refers to features that are added to a building's design to enhance its aesthetic appeal. The crossword solution for this term is 'ELLS, ' which stands for 'Extended Length Logs.' These logs are typically used to create a rustic look and are often seen in log cabins or other structures with a country-style design. They are also used to add height to a building, creating an impressive and eye-catching effect.