diff --git a/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Apartment.java b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Apartment.java
new file mode 100644
index 0000000..4c26f68
--- /dev/null
+++ b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Apartment.java
@@ -0,0 +1,25 @@
+package com.example.apartment_predictor.lab01;
+
+public class Apartment extends Property {
+
+    protected int numberOfRooms;
+
+    public Apartment(double area, int locationRating, int numberOfRooms) {
+        super(area, locationRating);
+        if (numberOfRooms <= 0) {
+            throw new IllegalArgumentException("numberOfRooms must be > 0. Provided: " + numberOfRooms);
+        }
+        this.numberOfRooms = numberOfRooms;
+    }
+
+    @Override
+    public String getPropertyType() {
+        return "Apartment";
+    }
+
+    @Override
+    public double calculatePrice() {
+        double basePrice = area * 120 + (numberOfRooms * 8000);
+        return basePrice * (1 + (locationRating * 0.04));
+    }
+}
diff --git a/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Duplex.java b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Duplex.java
new file mode 100644
index 0000000..c119bf1
--- /dev/null
+++ b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Duplex.java
@@ -0,0 +1,25 @@
+package com.example.apartment_predictor.lab01;
+
+public class Duplex extends Apartment {
+
+    private boolean hasSeparateUtilities;
+
+    public Duplex(double area, int locationRating, int numberOfRooms, boolean hasSeparateUtilities) {
+        super(area, locationRating, numberOfRooms);
+        this.hasSeparateUtilities = hasSeparateUtilities;
+    }
+
+    @Override
+    public String getPropertyType() {
+        return "Duplex (2 Units)";
+    }
+
+    @Override
+    public double calculatePrice() {
+        double basePrice = area * 220 + (numberOfRooms * 12000);
+        if (hasSeparateUtilities) {
+            basePrice *= 1.15;
+        }
+        return basePrice * (1 + (locationRating * 0.09));
+    }
+}
diff --git a/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/House.java b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/House.java
new file mode 100644
index 0000000..2539a84
--- /dev/null
+++ b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/House.java
@@ -0,0 +1,25 @@
+package com.example.apartment_predictor.lab01;
+
+public class House extends Apartment {
+
+    private boolean hasGarage;
+
+    public House(double area, int locationRating, int numberOfRooms, boolean hasGarage) {
+        super(area, locationRating, numberOfRooms);
+        this.hasGarage = hasGarage;
+    }
+
+    @Override
+    public String getPropertyType() {
+        return "Single-Family House";
+    }
+
+    @Override
+    public double calculatePrice() {
+        double basePrice = area * 180 + (numberOfRooms * 15000);
+        if (hasGarage) {
+            basePrice += 25000;
+        }
+        return basePrice * (1 + (locationRating * 0.06));
+    }
+}
diff --git a/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Property.java b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Property.java
new file mode 100644
index 0000000..59e4be9
--- /dev/null
+++ b/ApartmentPredictor/src/main/java/com/example/apartment_predictor/lab01/Property.java
@@ -0,0 +1,24 @@
+package com.example.apartment_predictor.lab01;
+
+public abstract class Property {
+
+    protected double area;
+    protected int locationRating;
+
+    protected Property(double area, int locationRating) {
+        if (area <= 0) {
+            throw new IllegalArgumentException("area must be > 0. Provided: " + area);
+        }
+        if (locationRating < 0 || locationRating > 5) {
+            throw new IllegalArgumentException("locationRating must be between 0 and 5. Provided: " + locationRating);
+        }
+        this.area = area;
+        this.locationRating = locationRating;
+    }
+
+    // Lab Variant 1
+    public abstract String getPropertyType();
+
+    // Lo dejamos porque el enunciado base lo tenía (aunque no lo uses ahora)
+    public abstract double calculatePrice();
+}
diff --git a/ApartmentPredictor/src/test/java/com/example/apartment_predictor/lab01/PropertyTypePolymorphismTest.java b/ApartmentPredictor/src/test/java/com/example/apartment_predictor/lab01/PropertyTypePolymorphismTest.java
new file mode 100644
index 0000000..4bf2086
--- /dev/null
+++ b/ApartmentPredictor/src/test/java/com/example/apartment_predictor/lab01/PropertyTypePolymorphismTest.java
@@ -0,0 +1,36 @@
+package com.example.apartment_predictor.lab01;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class PropertyTypePolymorphismTest {
+
+    @Test
+    void getPropertyType_returnsCorrectType_forEachSubclass() {
+        Property apartment = new Apartment(90.0, 3, 2);
+        Property house = new House(80.0, 3, 3, true);
+        Property duplex = new Duplex(250.0, 3, 6, false);
+
+        assertEquals("Apartment", apartment.getPropertyType());
+        assertEquals("Single-Family House", house.getPropertyType());
+        assertEquals("Duplex (2 Units)", duplex.getPropertyType());
+    }
+
+    @Test
+    void getPropertyType_polymorphismWorks_insideAListOfProperty() {
+        List<Property> properties = List.of(
+                new Apartment(90.0, 3, 2),
+                new House(80.0, 3, 3, true),
+                new Duplex(250.0, 3, 6, false)
+        );
+
+        List<String> types = properties.stream()
+                .map(Property::getPropertyType)
+                .toList();
+
+        assertEquals(List.of("Apartment", "Single-Family House", "Duplex (2 Units)"), types);
+    }
+}