diff --git a/Makefile b/Makefile
index a1c4f67..ac96b22 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ test:
 	lua ./unittest/run.lua
 
 doc:
-	ldoc -f markdown -a mods/vxl/
+	ldoc -f markdown -a mods/stm/
 
 check:
-	luacheck mods/vxl/
+	luacheck mods/stm/
diff --git a/mods/stm/build_order.lua b/mods/stm/build_order.lua
index 0ac7fc1..561b4be 100644
--- a/mods/stm/build_order.lua
+++ b/mods/stm/build_order.lua
@@ -14,24 +14,41 @@ end)
 local TASK_TIMEOUT = 3 * stm.TIME_SCALE
 
 --- Creates a build order from a schematic function.
--- @param min vector for the bounding rectangle's min point
--- @param max vector for the bounding rectangle's max point
--- @param fn callback function taking arguments `(x,y,z)` and returning a
---   string such as "default:dirt" or "air"
+-- @param bounding rectangle's min point
+-- @param rectangle's max point
+-- @param spec function, table, or string describing the nodes to be set
+-- during construction.
+-- If `spec` is a string it must be a filename relative to /schematics/.
+-- If the file ends in .lua, the file is evaluated with dofile and its result
+-- is expected to be one of the other supported spec types (a function or
+-- table).
+-- 
+-- If `spec` is a table it is assumed to have values of the following form,
+-- specifying positions and node names for the build order:
+--
+--     { pos = <vector>, name = <string> }
+--
+-- If `spec` is a function, it must take arguments of the form `(min, max)`, where:
+--
+--   - `min` is the minimum position of the build order in world coords
+--   - `max` is the maximum position of the build order in world coords
+--   - the function is expected to return a table as described above
 -- @return the newly created BuildOrder
-function BuildOrder.create(min, max, fn)
+function BuildOrder.create(min, max, spec)
   local result = BuildOrder.new()
+  if type(spec) == 'string' then
+    spec = dofile(stm.base_path .. "/schematics/" .. spec)
+  end
+
+  if type(spec) == 'function' then
+    spec = spec(min,max)
+  end
+
   result.min = min
   result.max = max
-  for x = min.x,max.x do
-    for y = min.y,max.y do
-      for z = min.z,max.z do
-        local name = fn(x,y,z)
-        if name then
-          result:push(vector.new(x,y,z), name)
-        end
-      end
-    end
+  -- TODO: truncate spec to given min/max extents?
+  for k,v in pairs(spec) do
+    result:push(v.pos, v.name)
   end
   return result
 end
diff --git a/mods/stm/character.lua b/mods/stm/character.lua
index c973b94..14ecc70 100644
--- a/mods/stm/character.lua
+++ b/mods/stm/character.lua
@@ -51,6 +51,7 @@ function Character:simulate(dt)
   if not ok then
     print('error performing task', err)
     stm.dump(self.tasks)
+    assert(false)
   end
   self:update_physics(dt)
 end
diff --git a/mods/stm/schematics/flatland.lua b/mods/stm/schematics/flatland.lua
new file mode 100644
index 0000000..877936c
--- /dev/null
+++ b/mods/stm/schematics/flatland.lua
@@ -0,0 +1,8 @@
+return function(min,max)
+  local build_fn = function(x,y,z)
+    if y >= min.y then return 'air' end
+    return 'default:dirt'
+  end
+
+  return stm.walk_aabb(min, max, build_fn)
+end
\ No newline at end of file
diff --git a/mods/stm/schematics/house.lua b/mods/stm/schematics/house.lua
new file mode 100644
index 0000000..6de25ca
--- /dev/null
+++ b/mods/stm/schematics/house.lua
@@ -0,0 +1,23 @@
+return function(min,max)
+  local build_fn = function(x,y,z)
+    if x == min.x or x == max.x or
+       y == max.y or
+       z == min.z or z == max.z
+    then
+      return "air"
+    elseif
+       x == min.x+1 or x == max.x-1 or
+       y == max.y-1 or
+       z == min.z+1 or z == max.z-1
+    then
+      local midx = math.floor(min.x + (max.x - min.x)*.5)
+      local midz = math.floor(min.z + (max.z - min.z)*.5)
+      if x == midx and z > midz and y <= min.y + 1 then
+        return "air"
+      end
+      return "default:stone"
+    end
+    return "air"
+  end
+  return stm.walk_aabb(min, max, build_fn)
+end
diff --git a/mods/stm/tasks/establish_municipality.lua b/mods/stm/tasks/establish_municipality.lua
index d4c0870..94ad47d 100644
--- a/mods/stm/tasks/establish_municipality.lua
+++ b/mods/stm/tasks/establish_municipality.lua
@@ -32,18 +32,13 @@ return {
 
     -- found a good spot
     local loc = Location.new({ type = Location.TYPE_MUNICIPALITY })
-    loc.pos = MapData.get_surface_pos(pos)
+    loc.pos = vector.new(pos.x, y_min, pos.z)
     loc.min = vector.new(pos.x - size, y_min, pos.z - size)
     loc.max = vector.new(pos.x + size, y_max, pos.z + size)
     Location.register(loc)
 
-    local build_fn = function(x,y,z)
-      if y >= loc.pos.y then return 'air' end
-      return 'default:dirt'
-    end
-
     -- create initial build orders for this location
-    local order = BuildOrder.create(loc.min, loc.max, build_fn)
+    local order = BuildOrder.create(loc.min, loc.max, 'flatland.lua')
     BuildOrder.register(order)
     loc:add_order(order)
 
diff --git a/mods/stm/tasks/find_residence.lua b/mods/stm/tasks/find_residence.lua
index fac92c1..72c7720 100644
--- a/mods/stm/tasks/find_residence.lua
+++ b/mods/stm/tasks/find_residence.lua
@@ -23,10 +23,6 @@ return {
       end
 
       char.municipality = loc.id
-      char:push_task('move', { dest = loc:get_position(), distance = 5 })
-      state.state = MOVE
-
-    elseif state.state == MOVE then
       state.state = REQUEST_LOCATION
 
     elseif state.state == REQUEST_LOCATION then
@@ -43,29 +39,11 @@ return {
       if not residence then return false end
       residence.type = Location.TYPE_RESIDENCE
       char.residence = residence.id
-      char:push_task('move', { dest = residence:get_position() })
       state.state = ENQUEUE_RESIDENCE
 
     elseif state.state == ENQUEUE_RESIDENCE then
       local residence = Location.get(char.residence)
-      local order = BuildOrder.create(residence.min, residence.max, function(x,y,z)
-        if x == residence.min.x or x == residence.max.x or
-           y == residence.max.y or
-           z == residence.min.z or z == residence.max.z
-        then
-          return "air"
-        elseif
-           x == residence.min.x+1 or x == residence.max.x-1 or
-           y == residence.max.y-1 or
-           z == residence.min.z+1 or z == residence.max.z-1
-        then
-          if x == residence.pos.x and z > residence.pos.z and y <= residence.min.y + 1 then
-            return "air"
-          end
-          return "default:stone"
-        end
-        return "air"
-      end)
+      local order = BuildOrder.create(residence.min, residence.max, 'house.lua')
 
       BuildOrder.register(order)
       char:push_task("build_lazily", { order = order.id })
diff --git a/mods/stm/util.lua b/mods/stm/util.lua
index d53a7e9..cd70d8b 100644
--- a/mods/stm/util.lua
+++ b/mods/stm/util.lua
@@ -126,4 +126,30 @@ function stm.count_pairs(t)
   return result
 end
 
+--- Iterates over all integer positions between `a` and `b`, applying `fn`
+-- @param a min extents of the aabb
+-- @param b max extents of the aabb
+-- @param fn callback function taking arguments `(x,y,z)` and returning a string
+-- @return an array of tables where each element has the form `{ pos = <vector>, name = <result for that position> }`
+function stm.walk_aabb(a,b,fn)
+  local result = { }
+  for x = math.min(a.x,b.x),math.max(a.x,b.x),1 do
+    for y = math.min(a.y,b.y),math.max(a.y,b.y),1 do
+      for z = math.min(a.z,b.z),math.max(a.z,b.z),1 do
+        local name = fn(x,y,z)
+        if name then
+          table.insert(result, { pos = vector.new(x,y,z), name = name }) 
+        end
+      end
+    end
+  end
+  return result
+end
+
+if minetest then
+  stm.base_path = minetest.get_modpath('stm')
+else
+  stm.base_path = './mods/stm/'
+end
+
 math.randomseed(os.time())
\ No newline at end of file
diff --git a/unittest/test_character.lua b/unittest/test_character.lua
index 7249ec6..0ba2c6e 100644
--- a/unittest/test_character.lua
+++ b/unittest/test_character.lua
@@ -101,5 +101,5 @@ function TestCharacter:testGravity()
     c:simulate(step)
   end
 
-  assert(math.abs(c.pos.y - 0.5) < 0.0001)
+  assert(math.abs(c.pos.y - 0.5) < 0.015)
 end
\ No newline at end of file