diff --git a/public/js/map-ui.js b/public/js/map-ui.js
index 9f6fe67..cb10e4b 100644
--- a/public/js/map-ui.js
+++ b/public/js/map-ui.js
@@ -247,13 +247,13 @@ document.querySelector(".popup-close").onclick = () => {
 document.querySelectorAll(".building").forEach((building) => {
   building.addEventListener("mouseenter", async (e) => {
     try {
-      const id = building.dataset.id;
+      // data-id bevorzugen, sonst ID aus href extrahieren (z.B. "/building/5" → "5")
+      const id = building.dataset.id || building.getAttribute("href")?.split("/").pop();
+      if (!id) return;
 
       if (!tooltipCache[id]) {
         const res = await fetch("/api/building/" + id);
-
         if (!res.ok) throw new Error("API Fehler");
-
         tooltipCache[id] = await res.json();
       }