diff --git a/coordinator/renderer.lua b/coordinator/renderer.lua
index 9c29c4b..0948e67 100644
--- a/coordinator/renderer.lua
+++ b/coordinator/renderer.lua
@@ -3,29 +3,21 @@ local util = require("scada-common.util")
 
 local core = require("graphics.core")
 
-local displaybox = require("graphics.elements.displaybox")
-local textbox = require("graphics.elements.textbox")
+local main_layout = require("coordinator.ui.main_layout")
+local unit_layout = require("coordinator.ui.unit_layout")
 
 local renderer = {}
 
-local gconf = {
-    -- root boxes
-    root = {
-        fgd = colors.black,
-        bkg = colors.lightGray
-    }
-}
-
 -- render engine
 local engine = {
     monitors = nil,
     dmesg_window = nil
 }
 
--- UI elements
+-- UI layouts
 local ui = {
-    main_box = nil,
-    unit_boxes = {}
+    main_layout = nil,
+    unit_layouts = {}
 }
 
 -- reset a display to the "default", but set text scale to 0.5
@@ -64,22 +56,18 @@ end
 
 -- start the coordinator GUI
 function renderer.start_ui()
-    local palette = core.graphics.cpair(gconf.root.fgd, gconf.root.bkg)
+    ui.main_layout = main_layout(engine.monitors.primary)
 
-    ui.main_box = displaybox{window=engine.monitors.primary,fg_bg=palette}
-
-    textbox{parent=ui.main_box,text="Nuclear Generation Facility SCADA Coordinator",alignment=core.graphics.TEXT_ALIGN.CENTER,height=1,fg_bg=core.graphics.cpair(colors.white,colors.gray)}
-
-    for _, monitor in pairs(engine.monitors.unit_displays) do
-        table.insert(ui.unit_boxes, displaybox{window=monitor,fg_bg=palette})
+    for id, monitor in pairs(engine.monitors.unit_displays) do
+        table.insert(ui.unit_layouts, unit_layout(monitor, id))
     end
 end
 
 -- close out the UI
 function renderer.close_ui()
     -- clear root UI elements
-    ui.main_box = nil
-    ui.unit_boxes = {}
+    ui.main_layout = nil
+    ui.unit_layouts = {}
 
     -- reset displays
     renderer.reset()
diff --git a/coordinator/util/dialog.lua b/coordinator/ui/dialog.lua
similarity index 100%
rename from coordinator/util/dialog.lua
rename to coordinator/ui/dialog.lua
diff --git a/coordinator/ui/main_layout.lua b/coordinator/ui/main_layout.lua
new file mode 100644
index 0000000..96d0a45
--- /dev/null
+++ b/coordinator/ui/main_layout.lua
@@ -0,0 +1,21 @@
+--
+-- Main SCADA Coordinator GUI
+--
+
+local core   = require("graphics.core")
+local layout = require("graphics.layout")
+
+local style = require("coordinator.ui.style")
+
+local displaybox = require("graphics.elements.displaybox")
+local textbox    = require("graphics.elements.textbox")
+
+local function init(monitor)
+    local main = layout.create(monitor, displaybox{window=monitor,fg_bg=style.root})
+
+    textbox{parent=main,text="Nuclear Generation Facility SCADA Coordinator",alignment=core.graphics.TEXT_ALIGN.CENTER,height=1,fg_bg=style.header}
+
+    return main
+end
+
+return init
diff --git a/coordinator/ui/style.lua b/coordinator/ui/style.lua
new file mode 100644
index 0000000..a148130
--- /dev/null
+++ b/coordinator/ui/style.lua
@@ -0,0 +1,11 @@
+
+local core = require("graphics.core")
+
+local style = {}
+
+-- MAIN LAYOUT --
+
+style.root = core.graphics.cpair(colors.black, colors.lightGray)
+style.header = core.graphics.cpair(colors.white,colors.gray)
+
+return style
diff --git a/coordinator/ui/unit_layout.lua b/coordinator/ui/unit_layout.lua
new file mode 100644
index 0000000..45884ca
--- /dev/null
+++ b/coordinator/ui/unit_layout.lua
@@ -0,0 +1,21 @@
+--
+-- Reactor Unit SCADA Coordinator GUI
+--
+
+local core   = require("graphics.core")
+local layout = require("graphics.layout")
+
+local style = require("coordinator.ui.style")
+
+local displaybox = require("graphics.elements.displaybox")
+local textbox    = require("graphics.elements.textbox")
+
+local function init(monitor, id)
+    local main = layout.create(monitor, displaybox{window=monitor,fg_bg=style.root})
+
+    textbox{parent=main,text="Reactor Unit #" .. id,alignment=core.graphics.TEXT_ALIGN.CENTER,height=1,fg_bg=style.header}
+
+    return main
+end
+
+return init
diff --git a/graphics/core.lua b/graphics/core.lua
index 91e7915..4bd0d9e 100644
--- a/graphics/core.lua
+++ b/graphics/core.lua
@@ -1,3 +1,7 @@
+--
+-- Graphics Core Functions and Objects
+--
+
 local core = {}
 
 local events = {}
diff --git a/graphics/layout.lua b/graphics/layout.lua
new file mode 100644
index 0000000..fe91cdd
--- /dev/null
+++ b/graphics/layout.lua
@@ -0,0 +1,71 @@
+local core = require("graphics.core")
+local util = require("scada-common.util")
+
+local displaybox = require("graphics.elements.displaybox")
+
+local layout = {}
+
+---@class stem
+---@field element graphics_element
+---@field children table
+
+function layout.create(window, default_fg_bg)
+    local self = {
+        root = displaybox{window=window,fg_bg=default_fg_bg},
+        tree = {}
+    }
+
+    -- recursive function to search layout tree for an element
+    ---@param id string element ID to look for
+    ---@param tree table tree to search in
+    ---@return stem|nil
+    local function lookup(id, tree)
+        for key, stem in pairs(tree) do
+            if key == id then
+                return stem
+            else
+                stem = lookup(id, stem.children)
+                if stem ~= nil then return stem end
+            end
+        end
+
+        return nil
+    end
+
+    ---@class layout
+    local public = {}
+
+    -- insert a new element
+    ---@param parent_id string|nil parent or nil for root
+    ---@param id string element ID
+    ---@param element graphics_element
+    function public.insert_at(parent_id, id, element)
+        if parent_id == nil then
+            self.tree[id] = { element = element, children = {} }
+        else
+            local parent = lookup(parent_id, self.tree)
+            if parent ~= nil then
+                parent.children[id] = { element = element, children = {} }
+            end
+        end
+    end
+
+    -- get an element by ID
+    ---@param id string element ID
+    ---@return graphics_element|nil
+    function public.get_element_by_id(id)
+        local elem = lookup(id, self.tree)
+---@diagnostic disable-next-line: need-check-nil
+        return util.trinary(elem == nil, nil, elem.element)
+    end
+
+    -- get the root element
+    ---@return graphics_element
+    function public.get_root()
+        return self.root
+    end
+
+    return public
+end
+
+return layout