diff --git a/api/booking-sheet.js b/api/booking-sheet.js
index 7657d09..1d873f7 100644
--- a/api/booking-sheet.js
+++ b/api/booking-sheet.js
@@ -6,6 +6,10 @@ const fs = require('fs');
 
 let sheetsClient = null;
 
+// In-memory cache for parsed booking sheet (2-min TTL)
+let sheetCache = { data: null, timestamp: 0 };
+const CACHE_TTL_MS = 2 * 60 * 1000;
+
 // Accommodation criteria mapping — maps accommodation_type to sheet matching rules
 const ACCOMMODATION_CRITERIA = {
   'ch-multi': {
@@ -164,6 +168,38 @@ async function parseBookingSheet() {
   return beds;
 }
 
+/**
+ * Cached wrapper around parseBookingSheet().
+ */
+async function getCachedBeds() {
+  const now = Date.now();
+  if (sheetCache.data && (now - sheetCache.timestamp) < CACHE_TTL_MS) {
+    return sheetCache.data;
+  }
+  const beds = await parseBookingSheet();
+  if (beds) {
+    sheetCache.data = beds;
+    sheetCache.timestamp = now;
+  }
+  return beds;
+}
+
+/**
+ * Check availability of all accommodation types for the given weeks.
+ * @param {string[]} selectedWeeks - e.g. ['week1', 'week2'] or ['week1','week2','week3','week4'] for full month
+ * @returns {object|null} Map of accommodation type → boolean (available)
+ */
+async function checkAvailability(selectedWeeks) {
+  const beds = await getCachedBeds();
+  if (!beds) return null;
+
+  const availability = {};
+  for (const type of Object.keys(ACCOMMODATION_CRITERIA)) {
+    availability[type] = !!findAvailableBed(beds, type, selectedWeeks);
+  }
+  return availability;
+}
+
 /**
  * Find an available bed matching the accommodation criteria for the given weeks.
  * A bed is "available" only if ALL requested week columns are empty.
@@ -257,6 +293,10 @@ async function assignBooking(guestName, accommodationType, selectedWeeks) {
       });
     }
 
+    // Invalidate cache after successful assignment
+    sheetCache.data = null;
+    sheetCache.timestamp = 0;
+
     console.log(`[Booking Sheet] Assigned ${guestName} to ${bed.venue} Room ${bed.room} (${bed.bedType}) for weeks: ${selectedWeeks.join(', ')}`);
 
     return {
@@ -271,4 +311,4 @@ async function assignBooking(guestName, accommodationType, selectedWeeks) {
   }
 }
 
-module.exports = { assignBooking, parseBookingSheet, findAvailableBed, ACCOMMODATION_CRITERIA };
+module.exports = { assignBooking, parseBookingSheet, findAvailableBed, checkAvailability, ACCOMMODATION_CRITERIA };
diff --git a/api/mollie.js b/api/mollie.js
index c1255d9..7654dc9 100644
--- a/api/mollie.js
+++ b/api/mollie.js
@@ -371,9 +371,10 @@ async function handleWebhook(req, res) {
               };
 
               try {
+                const bookingAlertEmail = process.env.BOOKING_ALERT_EMAIL || 'jeff@jeffemmett.com';
                 await smtp.sendMail({
                   from: process.env.EMAIL_FROM || 'Valley of the Commons <contact@valleyofthecommons.com>',
-                  to: 'team@valleyofthecommons.com',
+                  to: bookingAlertEmail,
                   subject: bookingNotification.subject,
                   html: bookingNotification.html,
                 });
diff --git a/apply.html b/apply.html
index bca26d9..0a40726 100644
--- a/apply.html
+++ b/apply.html
@@ -177,6 +177,28 @@
         .week-card .dates { font-size: 0.8rem; color: #666; margin-bottom: 0.5rem; }
         .week-card .desc { font-size: 0.85rem; color: #555; }
 
+        .week-card.sold-out {
+            opacity: 0.5;
+            pointer-events: none;
+            position: relative;
+        }
+
+        .week-card.sold-out::after {
+            content: 'Sold Out';
+            position: absolute;
+            top: 1rem;
+            right: 1rem;
+            background: rgba(200, 50, 50, 0.12);
+            border: 1px solid rgba(200, 50, 50, 0.4);
+            color: #c83232;
+            font-size: 0.75rem;
+            font-weight: 600;
+            padding: 0.2rem 0.6rem;
+            border-radius: 6px;
+            text-transform: uppercase;
+            letter-spacing: 0.05em;
+        }
+
         /* Select-all card */
         .select-all-card {
             border-style: dashed;
@@ -1329,6 +1351,34 @@
         }
 
         // ===== Week selection =====
+        // Fetch and apply accommodation availability based on selected weeks
+        async function fetchAndApplyAvailability() {
+            const weeks = getSelectedWeeks();
+            if (weeks.length === 0) return;
+            try {
+                const res = await fetch(`/api/accommodation-availability?weeks=${encodeURIComponent(weeks.join(','))}`);
+                if (!res.ok) return;
+                const availability = await res.json();
+                document.querySelectorAll('input[name="room_type"]').forEach(radio => {
+                    const type = radio.value;
+                    const card = radio.closest('.week-card');
+                    if (type in availability && !availability[type]) {
+                        card.classList.add('sold-out');
+                        card.classList.remove('selected');
+                        radio.checked = false;
+                        if (document.getElementById('accommodation_type').value === type) {
+                            document.getElementById('accommodation_type').value = '';
+                            updatePriceSummary();
+                        }
+                    } else {
+                        card.classList.remove('sold-out');
+                    }
+                });
+            } catch (e) {
+                // Network error — leave all options enabled
+            }
+        }
+
         function toggleWeek(card) {
             const cb = card.querySelector('input');
             cb.checked = !cb.checked;
@@ -1336,6 +1386,8 @@
             syncSelectAll();
             updatePriceSummary();
             saveFormData();
+            // Re-check availability when weeks change
+            if (document.getElementById('need_accommodation').checked) fetchAndApplyAvailability();
         }
 
         function toggleAllWeeks(card) {
@@ -1350,6 +1402,7 @@
             });
             updatePriceSummary();
             saveFormData();
+            if (document.getElementById('need_accommodation').checked) fetchAndApplyAvailability();
         }
 
         function syncSelectAll() {
@@ -1376,6 +1429,8 @@
                     document.querySelectorAll('input[name="room_type"]').forEach(r => { r.checked = false; r.closest('.week-card').classList.remove('selected'); });
                     document.getElementById('ch-rooms').style.display = 'none';
                     document.getElementById('hh-rooms').style.display = 'none';
+                } else {
+                    fetchAndApplyAvailability();
                 }
             }
 
@@ -1402,6 +1457,10 @@
         }
 
         function selectRoom(roomType) {
+            // Prevent selecting sold-out rooms
+            const radio = document.querySelector(`input[name="room_type"][value="${roomType}"]`);
+            if (radio && radio.closest('.week-card').classList.contains('sold-out')) return;
+
             document.querySelectorAll('input[name="room_type"]').forEach(r => {
                 r.checked = (r.value === roomType);
                 r.closest('.week-card').classList.toggle('selected', r.checked);
diff --git a/server.js b/server.js
index 96091fd..2f58c48 100644
--- a/server.js
+++ b/server.js
@@ -50,6 +50,30 @@ app.post('/api/mollie/webhook', vercelToExpress(handleWebhook));
 app.all('/api/mollie/status', vercelToExpress(getPaymentStatus));
 app.get('/api/mollie/resume', vercelToExpress(resumePayment));
 
+// Accommodation availability check
+const { checkAvailability } = require('./api/booking-sheet');
+const VALID_WEEKS = new Set(['week1', 'week2', 'week3', 'week4']);
+app.get('/api/accommodation-availability', async (req, res) => {
+  try {
+    const weeksParam = (req.query.weeks || '').trim();
+    if (!weeksParam) {
+      return res.status(400).json({ error: 'weeks parameter required (e.g. week1,week2)' });
+    }
+    const selectedWeeks = weeksParam.split(',').filter(w => VALID_WEEKS.has(w));
+    if (selectedWeeks.length === 0) {
+      return res.status(400).json({ error: 'No valid weeks provided' });
+    }
+    const availability = await checkAvailability(selectedWeeks);
+    if (!availability) {
+      return res.status(503).json({ error: 'Booking sheet not configured' });
+    }
+    res.json(availability);
+  } catch (error) {
+    console.error('Availability check error:', error);
+    res.status(500).json({ error: 'Failed to check availability' });
+  }
+});
+
 // Static files
 app.use(express.static(path.join(__dirname), {
   extensions: ['html'],