Although this is a dispute between Beis Shammai and Beis Hillel, according to the answer posted here it appears the dispute regarding this particular halacha is based on Rav and Shmuel in Pesachim (106b).
Nonetheless, see Rema on (271:12) or here
וי"א דלכתחלה יש ליטול ידיו קודם הקידוש ולקדש על היין (הרא"ש ומרדכי פרק
ע"פ (ורשב"א) והגה"מ פכ"ט, והטור). וכן המנהג פשוט במדינות אלו (סב) ואין
לשנות רק בליל פסח, כמו שיתבאר סי' תע"ג
Rema: There are those that say that in the first place (l'khatchila) one should wash the hands before Kiddush, then make the Kiddush on the wine [presumably followed by the blessing on the bread]. And this is the obvious custom in these lands, and one should not change except on the eve of Passover [at the seder, when we say the Kiddush first and wash for the matzah considerably later].
Washing ones hands before or after kiddush is a machlokes rishonim which the Rema follows the Rishonim (Rosh, Rashba, Mordechai, etc) who hold to wash before kiddush. Yekkes seem to follow the Rema the vast majority of the time. It doesn't appear to be a question of following Beis Shammai or Beis Hillel. The Yekkes are following the Rema, who in turn follows rishonim who hold to wash before kiddush.