diff --git a/src/app/properties.rs b/src/app/properties.rs
index 1bfa1bc9e..f7a40df88 100644
--- a/src/app/properties.rs
+++ b/src/app/properties.rs
@@ -93,6 +93,11 @@ impl OpenCADStudio {
                 crate::entities::common::UnitContext::from_header(h),
             );
         }
+        {
+            // Which text styles fix their own height — the height rows read it
+            // to decide whether they are editable.
+            crate::entities::common::set_fixed_text_heights(&self.tabs[i].scene.document);
+        }
 
         let layer_names: Vec<String> = self.tabs[i]
             .scene
diff --git a/src/entities/attribute.rs b/src/entities/attribute.rs
index 0d9d2aca6..b0910983d 100644
--- a/src/entities/attribute.rs
+++ b/src/entities/attribute.rs
@@ -468,7 +468,13 @@ impl PropertyEditable for AttributeDefinition {
                         .collect(),
                 },
             },
-            edit(t!("Height").as_ref(), "att_h", self.height),
+            // Fixed by the style when the style fixes its height.
+            crate::entities::common::num_prop(
+                t!("Height").as_ref(),
+                "att_h",
+                self.height,
+                crate::entities::common::style_fixed_height(&self.text_style).is_none(),
+            ),
             edit_angle(t!("Rotation").as_ref(), "att_rot", self.rotation.to_degrees()),
             edit(t!("Width factor").as_ref(), "att_wf", self.width_factor),
             edit_angle(t!("Obliquing").as_ref(), "att_ob", self.oblique_angle.to_degrees()),
@@ -739,7 +745,13 @@ impl PropertyEditable for AttributeEntity {
                         "atte_annotative",
                         bool_yn(self.flags.annotative),
                     ),
-                    edit(t!("Height").as_ref(), "atte_h", self.height),
+                    // Fixed by the style when the style fixes its height.
+                    crate::entities::common::num_prop(
+                        t!("Height").as_ref(),
+                        "atte_h",
+                        self.height,
+                        crate::entities::common::style_fixed_height(&self.text_style).is_none(),
+                    ),
                     edit_angle(t!("Rotation").as_ref(), "atte_rot", self.rotation.to_degrees()),
                     edit(t!("Width factor").as_ref(), "atte_wf", self.width_factor),
                     edit_angle(t!("Obliquing").as_ref(), "atte_ob", self.oblique_angle.to_degrees()),
diff --git a/src/entities/common.rs b/src/entities/common.rs
index 6d1315ceb..8a18702c5 100644
--- a/src/entities/common.rs
+++ b/src/entities/common.rs
@@ -53,6 +53,38 @@ thread_local! {
     }) };
 }
 
+thread_local! {
+    /// Text styles that fix their own height, by lowercased name.
+    ///
+    /// A style with a non-zero height fixes the size of everything drawn in it
+    /// — the CAD that writes the file skips the height prompt for such a style,
+    /// and the properties palette shows the height without letting it be
+    /// changed. The panel builders are handed an entity, not the document it
+    /// came from, so the lookup rides here beside the unit context, seeded from
+    /// the same place.
+    static FIXED_TEXT_HEIGHTS: std::cell::RefCell<rustc_hash::FxHashMap<String, f64>> =
+        std::cell::RefCell::new(rustc_hash::FxHashMap::default());
+}
+
+/// Record which text styles fix their height, from the drawing's style table.
+pub fn set_fixed_text_heights(document: &acadrust::CadDocument) {
+    FIXED_TEXT_HEIGHTS.with(|cell| {
+        let mut map = cell.borrow_mut();
+        map.clear();
+        for style in document.text_styles.iter() {
+            if style.height > 0.0 {
+                map.insert(style.name.to_ascii_lowercase(), style.height);
+            }
+        }
+    });
+}
+
+/// The height `style` fixes, or `None` when it leaves the height to the entity.
+pub fn style_fixed_height(style: &str) -> Option<f64> {
+    let key = style.trim().to_ascii_lowercase();
+    FIXED_TEXT_HEIGHTS.with(|cell| cell.borrow().get(&key).copied())
+}
+
 /// Set the per-thread unit context. Properties helpers consult it when
 /// they format f64 values into display strings.
 pub fn set_unit_context(ctx: UnitContext) {
diff --git a/src/entities/mtext.rs b/src/entities/mtext.rs
index 74b2dfcbb..0abf0adef 100644
--- a/src/entities/mtext.rs
+++ b/src/entities/mtext.rs
@@ -311,7 +311,13 @@ fn properties(t: &MText, text_style_names: &[String]) -> Vec<PropSection> {
                             .collect(),
                     },
                 },
-                edit(t!("Text height").as_ref(), "height", t.height),
+                // Fixed by the style when the style says so — see Text.
+                crate::entities::common::num_prop(
+                    t!("Text height").as_ref(),
+                    "height",
+                    t.height,
+                    crate::entities::common::style_fixed_height(&t.style).is_none(),
+                ),
                 edit_angle(t!("Rotation").as_ref(), "rotation", t.rotation.to_degrees()),
                 edit(t!("Line space factor").as_ref(), "line_spacing", t.line_spacing_factor),
                 edit(t!("Line space distance").as_ref(), "line_space_distance", line_space_distance),
diff --git a/src/entities/text.rs b/src/entities/text.rs
index 7b47673ea..e8eed635e 100644
--- a/src/entities/text.rs
+++ b/src/entities/text.rs
@@ -325,7 +325,14 @@ fn properties(t: &Text, text_style_names: &[String]) -> Vec<PropSection> {
                         .collect(),
                     },
                 },
-                edit(t!("Height").as_ref(), "height", t.height),
+                // A style that fixes its height fixes this text's too, so the
+                // value shows but cannot be changed here.
+                crate::entities::common::num_prop(
+                    t!("Height").as_ref(),
+                    "height",
+                    t.height,
+                    crate::entities::common::style_fixed_height(&t.style).is_none(),
+                ),
                 edit_angle(t!("Rotation").as_ref(), "rotation", t.rotation.to_degrees()),
                 edit(t!("Width factor").as_ref(), "width_factor", t.width_factor),
                 edit_angle(t!("Obliquing").as_ref(), "oblique_angle", t.oblique_angle.to_degrees()),