diff --git a/src/yamlbuilder/TensegrityModel.cpp b/src/yamlbuilder/TensegrityModel.cpp
index a9f4b7f9d..57641ab3a 100644
--- a/src/yamlbuilder/TensegrityModel.cpp
+++ b/src/yamlbuilder/TensegrityModel.cpp
@@ -72,10 +72,13 @@ void TensegrityModel::setup(tgWorld& world) {
 
 void TensegrityModel::addChildren(tgStructure& structure, const std::string& structurePath, tgBuildSpec& spec, const Yam& children) {
     if (!children) return;
+    std::string structureAttributeKeys[] = {"path", "rotation", "translation", "scale", "offset"};
+    std::vector<std::string> structureAttributeKeysVector(structureAttributeKeys, structureAttributeKeys + sizeof(structureAttributeKeys) / sizeof(std::string));
 
     // add all the children first
     for (YAML::const_iterator child = children.begin(); child != children.end(); ++child) {
         Yam childAttributes = child->second;
+        yamlContainsOnly(childAttributes, structurePath, structureAttributeKeysVector);
         // multiple children can be defined using the syntax: child1/child2/child3...
         // (add a slash so that each child is a string with a its name and a slash at the end)
         std::string childCombos = child->first.as<std::string>() + "/";
@@ -187,6 +190,12 @@ void TensegrityModel::addChildTranslation(tgStructure& childStructure, const Yam
 
 void TensegrityModel::buildStructure(tgStructure& structure, const std::string& structurePath, tgBuildSpec& spec) {
     Yam root = YAML::LoadFile(structurePath);
+    // Validate YAML
+    std::string rootKeys[] = {"nodes", "pair_groups", "builders", "substructures", "bond_groups"};
+    std::vector<std::string> rootKeysVector(rootKeys, rootKeys + sizeof(rootKeys) / sizeof(std::string));
+    yamlContainsOnly(root, structurePath, rootKeysVector);
+    yamlNoDuplicates(root, structurePath);
+
     addChildren(structure, structurePath, spec, root["substructures"]);
     addBuilders(spec, root["builders"]);
     addNodes(structure, root["nodes"]);
@@ -471,8 +480,8 @@ tgStructure& TensegrityModel::getStructure(tgStructure& parentStructure, const s
 
 void TensegrityModel::addBuilders(tgBuildSpec& spec, const Yam& builders) {
     for (YAML::const_iterator builder = builders.begin(); builder != builders.end(); ++builder) {
-
         std::string tagMatch = builder->first.as<std::string>();
+        if (!builder->second["class"]) throw std::invalid_argument("Builder class not supplied for tag: " + tagMatch);
         std::string builderClass = builder->second["class"].as<std::string>();
         Yam parameters = builder->second["parameters"];
 
@@ -602,6 +611,32 @@ void TensegrityModel::addKinematicActuatorBuilder(const std::string& builderClas
     // add more builders that use tgKinematicActuator::Config here
 }
 
+void TensegrityModel::yamlNoDuplicates(const Yam& yam, const std::string structurePath) {
+    std::set<std::string> keys;
+    for (YAML::const_iterator iter = yam.begin(); iter != yam.end(); ++iter) {
+        Yam child = iter->second;
+        if (child.Type() == YAML::NodeType::Map) {
+            yamlNoDuplicates(child, structurePath);
+        }
+        std::string keyName = iter->first.as<std::string>();
+        if (keys.find(keyName) == keys.end()) {
+            keys.insert(keyName);
+        }
+        else {
+            throw std::invalid_argument(structurePath.substr(structurePath.rfind("/") + 1) + " contains duplicate key: " + keyName);
+        }
+    }
+}
+
+void TensegrityModel::yamlContainsOnly(const Yam& yam, const std::string structurePath, const std::vector<std::string> keys) {
+    for (YAML::const_iterator key = yam.begin(); key != yam.end(); ++key) {
+        std::string keyName = key->first.as<std::string>();
+        if (std::find(keys.begin(), keys.end(), keyName) == keys.end()) {
+            throw std::invalid_argument(structurePath.substr(structurePath.rfind("/") + 1) + " contains invalid key: " + keyName);
+        }
+    }
+}
+
 void TensegrityModel::step(double timeStep) {
     if (timeStep <= 0.0) {
         throw std::invalid_argument("time step is not positive");
diff --git a/src/yamlbuilder/TensegrityModel.h b/src/yamlbuilder/TensegrityModel.h
index b360ca683..c24dd7359 100644
--- a/src/yamlbuilder/TensegrityModel.h
+++ b/src/yamlbuilder/TensegrityModel.h
@@ -57,76 +57,76 @@ class TensegrityModel : public tgSubject<TensegrityModel>, public tgModel
     /*
      * Default rod radius.
      */
-    const double rodRadius = 0.5;
+    const static double rodRadius = 0.5;
     /*
      * Default rod density.
      */
-    const double rodDensity = 1.0;
+    const static double rodDensity = 1.0;
     /*
      * Default rod friction.
      */
-    const double rodFriction = 1.0;
+    const static double rodFriction = 1.0;
     /*
      * Default rod roll friction.
      */
-    const double rodRollFriction = 0.0;
+    const static double rodRollFriction = 0.0;
     /*
      * Default rod restitution.
      */
-    const double rodRestitution = 0.2;
+    const static double rodRestitution = 0.2;
 
     /*
      * Default string stiffness.
      */
-    const double stringStiffness = 1000.0;
+    const static double stringStiffness = 1000.0;
     /*
      * Default string damping.
      */
-    const double stringDamping = 10.0;
+    const static double stringDamping = 10.0;
     /*
      * Default string pretension.
      */
-    const double stringPretension = 0.0;
+    const static double stringPretension = 0.0;
     /*
      * Default string radius.
      */
-    const double stringRadius = 1.0;
+    const static double stringRadius = 1.0;
     /*
      * Default string motor friction.
      */
-    const double stringMotorFriction = 0.0;
+    const static double stringMotorFriction = 0.0;
     /*
      * Default string motor intertia.
      */
-    const double stringMotorInertia = 1.0;
+    const static double stringMotorInertia = 1.0;
     /*
      * Default string back drivable (boolean).
      */
-    const double stringBackDrivable = 0;
+    const static double stringBackDrivable = 0;
     /*
      * Default string history (boolean).
      */
-    const double stringHistory = 0;
+    const static double stringHistory = 0;
     /*
      * Default string max tension.
      */
-    const double stringMaxTension = 1000.0;
+    const static double stringMaxTension = 1000.0;
     /*
      * Default string target velocity.
      */
-    const double stringTargetVelocity = 100.0;
+    const static double stringTargetVelocity = 100.0;
     /*
      * Default string min actual length.
      */
-    const double stringMinActualLength = 0.1;
+    const static double stringMinActualLength = 0.1;
     /*
      * Default string min rest length.
      */
-    const double stringMinRestLength = 0.1;
+    const static double stringMinRestLength = 0.1;
     /*
      * Default string rotation.
      */
-    const double stringRotation = 0;
+    const static double stringRotation = 0;
 
     /*
      * YAML-encoded structure path.
@@ -322,6 +322,17 @@ class TensegrityModel : public tgSubject<TensegrityModel>, public tgModel
      * Responsible for adding a builder that uses the tgKinematicActuator config
      */
     void addKinematicActuatorBuilder(const std::string& builderClass, const std::string& tagMatch, const Yam& parameters, tgBuildSpec& spec);
+
+    /*
+     * Ensures YAML node contains only keys from the supplied vector
+     */
+    void yamlContainsOnly(const Yam& yam, const std::string structurePath, const std::vector<std::string> keys);
+
+    /*
+     * Ensures that YAML has all unique keys within each map
+     */
+    void yamlNoDuplicates(const Yam& yam, const std::string structurePath);
+
 };
 
 #endif  // TENSEGRITY_MODEL_H