diff --git a/docs/changelog.txt b/docs/changelog.txt
index 032ca52ad..81a0f4f60 100644
--- a/docs/changelog.txt
+++ b/docs/changelog.txt
@@ -37,6 +37,8 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 - `prospector`: prospector tool in fort mode is now available. embark prospect is not yet available and is disabled at this time.
 
 ## Fixes
+- `buildingplan`: filters are now properly applied to planned stairs
+- `buildingplan`: existing carved up/down stairs are now taken into account when determining which stair shape to construct
 - `buildingplan`: upright spike traps are now placed extended rather than retracted
 - `buildingplan`: you can no longer designate constructions on tiles with magma or deep water
 - `buildingplan`: fixed material filter getting lost for planning buildings on save/reload
diff --git a/plugins/buildingplan/buildingplan.cpp b/plugins/buildingplan/buildingplan.cpp
index 1e2d2c80e..fd77194e5 100644
--- a/plugins/buildingplan/buildingplan.cpp
+++ b/plugins/buildingplan/buildingplan.cpp
@@ -9,6 +9,7 @@
 
 #include "modules/World.h"
 
+#include "df/construction_type.h"
 #include "df/item.h"
 #include "df/job_item.h"
 #include "df/world.h"
@@ -282,6 +283,18 @@ static void clear_state(color_ostream &out) {
     call_buildingplan_lua(&out, "reload_pens");
 }
 
+static int16_t get_subtype(df::building *bld) {
+    if (!bld)
+        return -1;
+
+    int16_t subtype = bld->getSubtype();
+    if (bld->getType() == df::building_type::Construction &&
+            subtype >= df::construction_type::UpStair &&
+            subtype <= df::construction_type::UpDownStair)
+        subtype = df::construction_type::UpDownStair;
+    return subtype;
+}
+
 DFhackCExport command_result plugin_load_data (color_ostream &out) {
     cycle_timestamp = 0;
     config = World::GetPersistentData(CONFIG_KEY);
@@ -315,7 +328,7 @@ DFhackCExport command_result plugin_load_data (color_ostream &out) {
             pb.remove(out);
             continue;
         }
-        BuildingTypeKey key(bld->getType(), bld->getSubtype(), bld->getCustomType());
+        BuildingTypeKey key(bld->getType(), get_subtype(bld), bld->getCustomType());
         if (pb.item_filters.size() != get_item_filters(out, key).getItemFilters().size()) {
             WARN(status).print("loaded state for building %d doesn't match world\n", pb.id);
             pb.remove(out);
@@ -604,11 +617,15 @@ static bool isPlannedBuilding(color_ostream &out, df::building *bld) {
 
 static bool addPlannedBuilding(color_ostream &out, df::building *bld) {
     DEBUG(status,out).print("entering addPlannedBuilding\n");
-    if (!bld || planned_buildings.count(bld->id)
-            || !isPlannableBuilding(out, bld->getType(), bld->getSubtype(),
-                                    bld->getCustomType()))
+    if (!bld || planned_buildings.count(bld->id))
         return false;
-    BuildingTypeKey key(bld->getType(), bld->getSubtype(), bld->getCustomType());
+
+    int16_t subtype = get_subtype(bld);
+
+    if (!isPlannableBuilding(out, bld->getType(), subtype, bld->getCustomType()))
+        return false;
+
+    BuildingTypeKey key(bld->getType(), subtype, bld->getCustomType());
     PlannedBuilding pb(out, bld, get_heat_safety_filter(key), get_item_filters(out, key));
     return registerPlannedBuilding(out, pb);
 }
diff --git a/plugins/lua/buildingplan/planneroverlay.lua b/plugins/lua/buildingplan/planneroverlay.lua
index e92824f5f..8231a8f46 100644
--- a/plugins/lua/buildingplan/planneroverlay.lua
+++ b/plugins/lua/buildingplan/planneroverlay.lua
@@ -782,7 +782,7 @@ function PlannerOverlay:get_stairs_subtype(pos, bounds)
         if opt == 'auto' then
             local tt = dfhack.maps.getTileType(pos)
             local shape = df.tiletype.attrs[tt].shape
-            if shape ~= df.tiletype_shape.STAIR_DOWN then
+            if shape ~= df.tiletype_shape.STAIR_DOWN and shape ~= df.tiletype_shape.STAIR_UPDOWN then
                 subtype = df.construction_type.UpStair
             end
         else
@@ -793,7 +793,7 @@ function PlannerOverlay:get_stairs_subtype(pos, bounds)
         if opt == 'auto' then
             local tt = dfhack.maps.getTileType(pos)
             local shape = df.tiletype.attrs[tt].shape
-            if shape ~= df.tiletype_shape.STAIR_UP then
+            if shape ~= df.tiletype_shape.STAIR_UP and shape ~= df.tiletype_shape.STAIR_UPDOWN then
                 subtype = df.construction_type.DownStair
             end
         else