diff --git a/apps/desktop/src/components/grid/DataGrid.vue b/apps/desktop/src/components/grid/DataGrid.vue
index c68b1d9848..2d65052a37 100644
--- a/apps/desktop/src/components/grid/DataGrid.vue
+++ b/apps/desktop/src/components/grid/DataGrid.vue
@@ -196,6 +196,7 @@ import type { DataGridSortDirection, DataGridSortMode } from "@/lib/dataGrid/dat
 import { DATA_GRID_COMPACT_TOPBAR_WIDTH, type DataGridReloadIntent, type DataGridToolbarActionCapability, type DataGridToolbarAutoRefreshCapability, type DataGridToolbarSaveCapability } from "@/lib/dataGrid/dataGridToolbar";
 import { getTableMetadataCapabilities } from "@/lib/table/tableMetadataCapabilities";
 import { getTableStructureCapabilities } from "@/lib/table/tableStructureCapabilities";
+import { reserveDataGridHeaderLine } from "@/lib/dataGrid/dataGridHeaderLayout";
 import { supportsTableStructureEditing } from "@/lib/database/databaseCapabilities";
 import { rememberDataGridConditionHistory } from "@/lib/dataGrid/dataGridConditionHistory";
 import { effectiveDatabaseTypeForConnection } from "@/lib/database/jdbcDialect";
@@ -441,6 +442,10 @@ function headerColumnType(column: string, actualColIdx: number): string {
   return resolved ? shortTypeName(compactHeaderColumnType(resolved)) : "";
 }
 
+const reserveColumnTypeLine = computed(() => reserveDataGridHeaderLine(showColumnTypesInHeader.value, props.result.columns, (column, index) => headerColumnType(column, index)));
+// Match the rendered header columns so comments from unprojected metadata cannot add an empty row.
+const reserveColumnCommentLine = computed(() => reserveDataGridHeaderLine(showColumnCommentsInHeader.value, props.result.columns, (column) => headerColumnComment(column)));
+
 function shortTypeName(t: string): string {
   const s = t.toLowerCase();
   if (s === "character varying") return "varchar";
@@ -7769,6 +7774,8 @@ const gridContextMenuItems = computed<ContextMenuItem[]>(() => {
                     :tooltip-disabled="columnHeaderTooltipsDisabled"
                     :column-type="headerColumnType(col.name, col.actualColIdx)"
                     :column-comment="headerColumnComment(col.name)"
+                    :show-type-line="reserveColumnTypeLine"
+                    :show-comment-line="reserveColumnCommentLine"
                     :tooltip-column-type="columnTypeMap.get(col.name)"
                     :tooltip-column-comment="columnCommentMap.get(col.name)"
                     :type-class="typeColorClass(headerColumnType(col.name, col.actualColIdx))"
diff --git a/apps/desktop/src/components/grid/DataGridColumnHeader.vue b/apps/desktop/src/components/grid/DataGridColumnHeader.vue
index 5dbf51c9c7..d1b98a348b 100644
--- a/apps/desktop/src/components/grid/DataGridColumnHeader.vue
+++ b/apps/desktop/src/components/grid/DataGridColumnHeader.vue
@@ -15,6 +15,8 @@ defineProps<{
   columnComment?: string;
   tooltipColumnType?: string;
   tooltipColumnComment?: string;
+  showTypeLine?: boolean;
+  showCommentLine?: boolean;
   typeClass?: HTMLAttributes["class"];
   dragClass?: HTMLAttributes["class"];
   columnStyle?: CSSProperties;
@@ -51,8 +53,10 @@ const emit = defineEmits<{
       <span class="flex min-w-0 items-center gap-1 overflow-hidden">
         <span class="flex min-w-0 flex-1 flex-col overflow-hidden">
           <span class="min-w-0 truncate leading-4">{{ name }}</span>
-          <span v-if="columnType" class="min-w-0 truncate text-[10px] font-normal leading-3" :class="typeClass" :title="columnType">{{ columnType }}</span>
-          <span v-if="columnComment" class="min-w-0 truncate text-[10px] font-normal leading-3 text-muted-foreground" :title="columnComment">{{ columnComment }}</span>
+          <span v-if="showTypeLine" data-grid-header-type-line class="h-3 min-w-0 truncate text-[10px] font-normal leading-3" :class="[typeClass, { invisible: !columnType }]" :title="columnType || undefined" :aria-hidden="columnType ? undefined : true">{{ columnType }}</span>
+          <span v-if="showCommentLine" data-grid-header-comment-line class="h-3 min-w-0 truncate text-[10px] font-normal leading-3 text-muted-foreground" :class="{ invisible: !columnComment }" :title="columnComment || undefined" :aria-hidden="columnComment ? undefined : true">{{
+            columnComment
+          }}</span>
         </span>
         <slot name="actions" />
       </span>
diff --git a/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts b/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
index b8f83fe147..963fad13d9 100644
--- a/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
+++ b/apps/desktop/src/components/grid/__tests__/DataGridSurfaces.spec.ts
@@ -212,6 +212,67 @@ describe("DataGridColumnHeader", () => {
     dispatch(handle, "dblclick");
     expect(autoFit).toHaveBeenCalledOnce();
   });
+
+  it("keeps configured type and comment lines mounted for columns without values", () => {
+    const empty = mountComponent(DataGridColumnHeader, {
+      name: "id",
+      actualColumnIndex: 0,
+      visibleColumnIndex: 0,
+      showTypeLine: true,
+      showCommentLine: true,
+      copyColumnNameLabel: "copy",
+      columnNameLabel: "name",
+      columnTypeLabel: "type",
+      columnCommentLabel: "comment",
+    });
+    const emptyType = findOne(empty.root, (node) => node.props["data-grid-header-type-line"] === "");
+    const emptyComment = findOne(empty.root, (node) => node.props["data-grid-header-comment-line"] === "");
+
+    expect(String(emptyType.props.class)).toContain("h-3");
+    expect(String(emptyType.props.class)).toContain("invisible");
+    expect(emptyType.props.title).toBeUndefined();
+    expect(String(emptyComment.props.class)).toContain("h-3");
+    expect(String(emptyComment.props.class)).toContain("invisible");
+    expect(emptyComment.props.title).toBeUndefined();
+
+    const populated = mountComponent(DataGridColumnHeader, {
+      name: "status",
+      actualColumnIndex: 1,
+      visibleColumnIndex: 1,
+      columnType: "varchar",
+      columnComment: "Current status",
+      showTypeLine: true,
+      showCommentLine: true,
+      copyColumnNameLabel: "copy",
+      columnNameLabel: "name",
+      columnTypeLabel: "type",
+      columnCommentLabel: "comment",
+    });
+    const populatedType = findOne(populated.root, (node) => node.props["data-grid-header-type-line"] === "");
+    const populatedComment = findOne(populated.root, (node) => node.props["data-grid-header-comment-line"] === "");
+
+    expect(String(populatedType.props.class)).not.toContain("invisible");
+    expect(populatedType.props.title).toBe("varchar");
+    expect(String(populatedComment.props.class)).not.toContain("invisible");
+    expect(populatedComment.props.title).toBe("Current status");
+  });
+
+  it("omits optional header lines when both display settings are off", () => {
+    const mounted = mountComponent(DataGridColumnHeader, {
+      name: "id",
+      actualColumnIndex: 0,
+      visibleColumnIndex: 0,
+      columnType: "number",
+      columnComment: "Identifier",
+      copyColumnNameLabel: "copy",
+      columnNameLabel: "name",
+      columnTypeLabel: "type",
+      columnCommentLabel: "comment",
+    });
+
+    expect(findAll(mounted.root, (node) => node.props["data-grid-header-type-line"] === "")).toHaveLength(0);
+    expect(findAll(mounted.root, (node) => node.props["data-grid-header-comment-line"] === "")).toHaveLength(0);
+  });
 });
 
 describe("DataGridFilterBuilder", () => {
diff --git a/apps/desktop/src/lib/__tests__/dataGrid/dataGridHeaderLayout.spec.ts b/apps/desktop/src/lib/__tests__/dataGrid/dataGridHeaderLayout.spec.ts
new file mode 100644
index 0000000000..392b9613cb
--- /dev/null
+++ b/apps/desktop/src/lib/__tests__/dataGrid/dataGridHeaderLayout.spec.ts
@@ -0,0 +1,36 @@
+import { describe, expect, it } from "vitest";
+import { reserveDataGridHeaderLine } from "@/lib/dataGrid/dataGridHeaderLayout";
+
+describe("reserveDataGridHeaderLine", () => {
+  it("reserves a line only when the setting and full-column content require it", () => {
+    const values = [{ text: "" }, { text: "later column" }];
+
+    expect(reserveDataGridHeaderLine(false, values, (value) => value.text)).toBe(false);
+    expect(reserveDataGridHeaderLine(true, values, (value) => value.text)).toBe(true);
+    expect(reserveDataGridHeaderLine(true, [{ text: "" }, { text: "  " }], (value) => value.text)).toBe(false);
+    expect(reserveDataGridHeaderLine(true, [], (value: { text: string }) => value.text)).toBe(false);
+  });
+
+  it("resolves all columns rather than relying on the currently rendered window", () => {
+    const visited: number[] = [];
+    const reserved = reserveDataGridHeaderLine(true, ["", "", "comment"], (value, index) => {
+      visited.push(index);
+      return value;
+    });
+
+    expect(reserved).toBe(true);
+    expect(visited).toEqual([0, 1, 2]);
+  });
+
+  it("does not reserve a comment line for a comment on an unprojected column", () => {
+    const comments = new Map([["internal_id", "Not selected"]]);
+
+    expect(reserveDataGridHeaderLine(true, ["id", "name"], (column) => comments.get(column))).toBe(false);
+  });
+
+  it("reserves a comment line when a projected column has a comment", () => {
+    const comments = new Map([["name", "Display name"]]);
+
+    expect(reserveDataGridHeaderLine(true, ["id", "name"], (column) => comments.get(column))).toBe(true);
+  });
+});
diff --git a/apps/desktop/src/lib/dataGrid/dataGridHeaderLayout.ts b/apps/desktop/src/lib/dataGrid/dataGridHeaderLayout.ts
new file mode 100644
index 0000000000..69417827f7
--- /dev/null
+++ b/apps/desktop/src/lib/dataGrid/dataGridHeaderLayout.ts
@@ -0,0 +1,4 @@
+/** Resolve header height from the full column set so virtual-window changes cannot resize it. */
+export function reserveDataGridHeaderLine<T>(enabled: boolean, values: readonly T[], resolveText: (value: T, index: number) => string | null | undefined): boolean {
+  return enabled && values.some((value, index) => Boolean(resolveText(value, index)?.trim()));
+}