diff --git a/src/3.4_pont_thermique.js b/src/3.4_pont_thermique.js
index 1d7f902..2be9c08 100644
--- a/src/3.4_pont_thermique.js
+++ b/src/3.4_pont_thermique.js
@@ -19,7 +19,7 @@ function tv_k(di, de, du, pc_id, enveloppe) {
     if (desc.match(/(.+) \/ (.+)/)) {
       desc_1 = desc.match(/(.+) \/ (.+)/)[1];
       desc_2 = desc.match(/(.+) \/ (.+)/)[2];
-    } else if (desc.match(/(.+)-(.+)/)[1]) {
+    } else if (desc.match(/(.+)-(.+)/)) {
       desc_1 = desc.match(/(.+)-(.+)/)[1];
       desc_2 = desc.match(/(.+)-(.+)/)[2];
     } else {
@@ -27,11 +27,20 @@ function tv_k(di, de, du, pc_id, enveloppe) {
       return;
     }
 
-    de.reference_1 = mur_list.find(
+    let ptMur = mur_list.find(
       (mur) =>
         mur.donnee_entree.description.includes(desc_1) ||
         mur.donnee_entree.description.includes(desc_2)
-    ).donnee_entree.reference;
+    );
+    if (ptMur) {
+      de.reference_1 = ptMur.donnee_entree.reference;
+    } else {
+      console.error(
+        `BUG: descriptions '${desc_1}' ou '${desc_2}' du pont thermique non reconnue dans les descriptions des murs`
+      );
+      return;
+    }
+
     let list_2;
     switch (type_liaison) {
       case 'refend / mur':
@@ -49,11 +58,19 @@ function tv_k(di, de, du, pc_id, enveloppe) {
         break;
     }
     if (list_2) {
-      de.reference_2 = list_2.find(
+      ptMur = list_2.find(
         (men) =>
           men.donnee_entree.description.includes(desc_2) ||
           men.donnee_entree.description.includes(desc_1)
-      ).donnee_entree.reference;
+      );
+      if (ptMur) {
+        de.reference_2 = ptMur.donnee_entree.reference;
+      } else {
+        console.error(
+          `BUG: descriptions '${desc_1}' ou '${desc_2}' du pont thermique non reconnue dans '${type_liaison}'`
+        );
+        return;
+      }
     }
   }
 
@@ -95,6 +112,10 @@ function tv_k(di, de, du, pc_id, enveloppe) {
           plancher.donnee_entree.reference === de.reference_1 ||
           plancher.donnee_entree.reference === de.reference_2
       );
+      if (!plancher) {
+        console.error('Did not find plancher reference:', de.reference_1, de.reference_2);
+        return;
+      }
       const isolation_plancher = requestInput(
         plancher.donnee_entree,
         plancher.donnee_utilisateur,
diff --git a/src/3_deperdition.js b/src/3_deperdition.js
index 13e276a..c6fd746 100644
--- a/src/3_deperdition.js
+++ b/src/3_deperdition.js
@@ -71,7 +71,7 @@ export default function calc_deperdition(cg, zc, th, ej, enveloppe, logement) {
   const porte_list = enveloppe.porte_collection.porte || [];
   const bv_list = enveloppe.baie_vitree_collection.baie_vitree || [];
   const pt_list = enveloppe.pont_thermique_collection.pont_thermique || [];
-  const vt_list = logement.ventilation_collection.ventilation;
+  const vt_list = logement.ventilation_collection.ventilation || [];
 
   mur_list.forEach((mur) => calc_mur(mur, zc, pc, ej));
   pb_list.forEach((pb) => calc_pb(pb, zc, pc, ej, pb_list));
@@ -87,14 +87,14 @@ export default function calc_deperdition(cg, zc, th, ej, enveloppe, logement) {
     calc_ventilation(vt, cg, th, Sdep, mur_list, ph_list, porte_list, bv_list);
   });
 
-  const d_mur = mur_list.reduce((acc, mur) => acc + Umur(mur), 0);
-  const d_pb = pb_list.reduce((acc, pb) => acc + Upb(pb), 0);
-  const d_ph = ph_list.reduce((acc, ph) => acc + Uph(ph), 0);
-  const d_bv = bv_list.reduce((acc, bv) => acc + Ubv(bv), 0);
-  const d_porte = porte_list.reduce((acc, porte) => acc + Uporte(porte), 0);
-  const d_pt = pt_list.reduce((acc, pt) => acc + Upt(pt), 0);
-  const hvent = vt_list.reduce((acc, vt) => acc + vt.donnee_intermediaire.hvent, 0);
-  const hperm = vt_list.reduce((acc, vt) => acc + vt.donnee_intermediaire.hperm, 0);
+  const d_mur = mur_list.reduce((acc, mur) => acc + Umur(mur) || 0, 0);
+  const d_pb = pb_list.reduce((acc, pb) => acc + Upb(pb) || 0, 0);
+  const d_ph = ph_list.reduce((acc, ph) => acc + Uph(ph) || 0, 0);
+  const d_bv = bv_list.reduce((acc, bv) => acc + Ubv(bv) || 0, 0);
+  const d_porte = porte_list.reduce((acc, porte) => acc + Uporte(porte) || 0, 0);
+  const d_pt = pt_list.reduce((acc, pt) => acc + Upt(pt) || 0, 0);
+  const hvent = vt_list.reduce((acc, vt) => acc + vt.donnee_intermediaire.hvent || 0, 0);
+  const hperm = vt_list.reduce((acc, vt) => acc + vt.donnee_intermediaire.hperm || 0, 0);
 
   return {
     hvent,
diff --git a/src/engine.js b/src/engine.js
index e0119ce..39772fe 100644
--- a/src/engine.js
+++ b/src/engine.js
@@ -36,9 +36,15 @@ export function calcul_3cl(dpe) {
   if (logement.enveloppe === undefined) {
     console.warn('vide: logement.enveloppe');
     return null;
-  } else if (logement.enveloppe.mur_collection === undefined) {
+  } else if (!logement.enveloppe.mur_collection) {
     console.warn('vide: logement.enveloppe.mur_collection');
     return null;
+  } else if (!logement.enveloppe.plancher_haut_collection) {
+    console.warn('vide: logement.enveloppe.plancher_haut_collection');
+    return null;
+  } else if (!logement.enveloppe.plancher_bas_collection) {
+    console.warn('vide: logement.enveloppe.plancher_bas_collection');
+    return null;
   }
 
   add_references(logement.enveloppe);