Final answer:
The Basilica of Sant'Andrea in Mantua, designed by Alberti, showcases his appreciation for Roman architectural space with its grand interior and large barrel vault. Alberti's use of classical elements in the Palazzo Rucellai also reflects his admiration for Roman design.
Step-by-step explanation:
The building of Leon Battista Alberti that demonstrates an appreciation of the spatial character of Roman imperial architecture is the Basilica of Sant'Andrea in Mantua, Italy. This structure is particularly noted for its monumental interior space, clearly influenced by Roman architecture. The grand barrel vault of the nave in the Basilica of Sant'Andrea is reminiscent of the large vaults characteristic of ancient Rome, indicating Alberti's reverence for classical architecture. He applied the principles of classical architecture to create a space that conveys a feeling of grandeur and monumentality, reflecting the greatness of the Roman architectural tradition in a Christian context. Furthermore, Alberti's use of classical architectural elements like columns and pilasters in his designs, as seen in the Palazzo Rucellai, also expresses his appreciation for Roman architectural aesthetics and spatial arrangements.