diff --git a/public/js/map-ui.js b/public/js/map-ui.js
index 755c478..0914ad4 100644
--- a/public/js/map-ui.js
+++ b/public/js/map-ui.js
@@ -1,6 +1,22 @@
 const popup = document.getElementById("building-popup");
 const title = document.getElementById("popup-title");
 
+function resetTabs() {
+  document
+    .querySelectorAll(".tab")
+    .forEach((t) => t.classList.remove("active"));
+  document
+    .querySelectorAll(".tab-content")
+    .forEach((c) => c.classList.remove("active"));
+
+  // erster Tab aktiv
+  const firstTab = document.querySelector(".tab");
+  const firstContent = document.querySelector(".tab-content");
+
+  if (firstTab) firstTab.classList.add("active");
+  if (firstContent) firstContent.classList.add("active");
+}
+
 document.querySelectorAll(".building").forEach((b) => {
   b.addEventListener("click", async (e) => {
     e.preventDefault();
@@ -17,6 +33,7 @@ document.querySelectorAll(".building").forEach((b) => {
     popup.style.top = "50%";
 
     popup.style.display = "block";
+    resetTabs();
 
     // AJAX Gebäudedaten laden
     const res = await fetch("/api" + url);