Why do Saber and Rin sound disappointed when they see inside Shiro's shed?
Tohsaka is probably disappointed because the shed is like Shirou's workshop. Tohsaka is a professional magus; her workshop probably has magical items and books and scrolls, but Shirou has broken junk.

Maybe, it's the same for Saber (but we do not know if Saber knows what a workshop should be like).