diff --git a/src/rfc3986/builder.py b/src/rfc3986/builder.py
index 85469ed..4cb6129 100644
--- a/src/rfc3986/builder.py
+++ b/src/rfc3986/builder.py
@@ -114,3 +114,23 @@ class URIBuilder(object):
             query=self.query,
             fragment=self.fragment,
         )
+
+    def add_host(self, host):
+        """Add hostname to the URI.
+
+        .. code-block:: python
+
+            >>> URIBuilder().add_host('google.com')
+            URIBuilder(scheme=None, userinfo=None, host='google.com',
+                    port=None, path=None, query=None, fragment=None)
+
+        """
+        return URIBuilder(
+            scheme=self.scheme,
+            userinfo=self.userinfo,
+            host=normalizers.normalize_host(host),
+            port=self.port,
+            path=self.path,
+            query=self.query,
+            fragment=self.fragment,
+        )
diff --git a/tests/test_builder.py b/tests/test_builder.py
index a2e8043..b10ffc2 100644
--- a/tests/test_builder.py
+++ b/tests/test_builder.py
@@ -65,3 +65,15 @@ def test_add_credentials_requires_username():
     """Verify one needs a username to add credentials."""
     with pytest.raises(ValueError):
         builder.URIBuilder().add_credentials(None, None)
+
+
+@pytest.mark.parametrize('hostname', [
+    'google.com',
+    'GOOGLE.COM',
+    'gOOgLe.COM',
+    'goOgLE.com',
+])
+def test_add_host(hostname):
+    """Verify we normalize hostnames in add_host."""
+    uribuilder = builder.URIBuilder().add_host(hostname)
+    assert uribuilder.host == 'google.com'