diff --git a/infrastructure/solar/__init__.py b/infrastructure/solar/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/infrastructure/solar/google_solar_api_client.py b/infrastructure/solar/google_solar_api_client.py
new file mode 100644
index 00000000..5e4698e9
--- /dev/null
+++ b/infrastructure/solar/google_solar_api_client.py
@@ -0,0 +1,22 @@
+from typing import Any, Literal
+
+
+class BuildingInsightsNotFoundError(Exception):
+    pass
+
+
+class GoogleSolarApiClient:
+    base_url: str = "https://solar.googleapis.com/v1"
+    MAX_RETRIES: int = 5
+    ENTITY_NOT_FOUND_ERROR: str = "Requested entity was not found."
+
+    def __init__(self, api_key: str) -> None:
+        raise NotImplementedError
+
+    def get_building_insights(
+        self,
+        longitude: float,
+        latitude: float,
+        required_quality: Literal["HIGH", "MEDIUM", "LOW"] = "MEDIUM",
+    ) -> dict[str, Any]:
+        raise NotImplementedError
diff --git a/tests/infrastructure/solar/__init__.py b/tests/infrastructure/solar/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/infrastructure/solar/test_google_solar_api_client.py b/tests/infrastructure/solar/test_google_solar_api_client.py
new file mode 100644
index 00000000..b7a7e45d
--- /dev/null
+++ b/tests/infrastructure/solar/test_google_solar_api_client.py
@@ -0,0 +1,33 @@
+from typing import Any
+from unittest.mock import MagicMock, patch
+
+import pytest
+import requests
+
+from infrastructure.solar.google_solar_api_client import (
+    BuildingInsightsNotFoundError,
+    GoogleSolarApiClient,
+)
+
+
+# ---------------------------------------------------------------------------
+# Slice 1: Successful response returns parsed JSON
+# ---------------------------------------------------------------------------
+
+
+def test_get_building_insights_returns_parsed_json() -> None:
+    # Arrange
+    client = GoogleSolarApiClient(api_key="test-key")
+    payload: dict[str, Any] = {"solarPotential": {"maxArrayPanelsCount": 20}}
+    mock_response = MagicMock()
+    mock_response.json.return_value = payload
+
+    with patch("requests.get", return_value=mock_response) as mock_get:
+        mock_response.raise_for_status.return_value = None
+
+        # Act
+        result = client.get_building_insights(longitude=-0.1278, latitude=51.5074)
+
+    # Assert
+    assert result == payload
+    mock_get.assert_called_once()