diff --git a/OpenRa.TechTreeTest/Building.cs b/OpenRa.TechTreeTest/Building.cs
deleted file mode 100644
index 1c2d13b9f8..0000000000
--- a/OpenRa.TechTreeTest/Building.cs
+++ /dev/null
@@ -1,126 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using OpenRa.FileFormats;
-using System.Drawing;
-using System.IO;
-
-namespace OpenRa.TechTreeTest
-{
-	[Flags]
-	public enum Race
-	{
-		None = 0,
-		Allies = 1,
-		Soviet = 2
-	}
-
-	class Building : IRAUnit
-	{
-		readonly string friendlyName;
-		readonly string tag;
-
-		public string FriendlyName
-		{
-			get { return friendlyName; }
-		}
-
-		public string Tag
-		{
-			get { return tag; }
-		}
-
-		string[] prerequisites;
-
-		public string[] Prerequisites
-		{
-			get { return prerequisites; }
-			set { prerequisites = value; }
-		}
-
-		int techLevel;
-
-		public int TechLevel
-		{
-			get { return techLevel; }
-			set { techLevel = value; }
-		}
-
-		Race owner;
-
-		public Race Owner
-		{
-			get { return owner; }
-			set { owner = value; }
-		}
-
-		public Building(string tag, string friendlyName)
-		{
-			this.friendlyName = friendlyName;
-			this.tag = tag;
-		}
-
-		public bool ShouldMakeBuildable(IEnumerable<string> buildings)
-		{
-			if (techLevel > 10 || techLevel < 0)
-				return false;
-
-			if (prerequisites.Length == 0)
-				return true;
-
-			List<string> p = new List<string>(prerequisites);
-			foreach (string b in buildings)
-				p.Remove(b);
-
-			return p.Count == 0;
-		}
-
-		public bool ShouldMakeUnbuildable(IEnumerable<string> buildings)
-		{
-			if (prerequisites.Length == 0)
-				return false;
-
-			List<string> p = new List<string>(prerequisites);
-			foreach (string b in buildings)
-				p.Remove(b);
-
-			return p.Count == prerequisites.Length;
-		}
-
-		bool buildable = false;
-		public bool Buildable { get { return buildable; } }
-
-		public void CheckPrerequisites(IEnumerable<string> buildings, Race currentRace)
-		{
-			if ((buildable && ShouldMakeUnbuildable(buildings)) || !((owner & currentRace) == currentRace))
-				buildable = false;
-			else if (!buildable && ShouldMakeBuildable(buildings))
-				buildable = true;
-		}
-
-		Bitmap icon;
-		public Bitmap Icon
-		{
-			get { return icon ?? (icon = LoadIcon(tag)); }
-		}
-
-		static Package package = new Package("../../../hires.mix");
-		static Palette palette = new Palette( File.OpenRead("../../../temperat.pal"));
-
-		static Bitmap LoadIcon(string tag)
-		{
-			string filename = tag + "icon.shp";
-
-			try
-			{
-				Stream s = package.GetContent(filename);
-				ShpReader reader = new ShpReader(s);
-				foreach (ImageHeader h in reader)
-					return BitmapBuilder.FromBytes(h.Image, reader.Width, reader.Height, palette);
-
-				return null;
-			}
-			catch (FileNotFoundException) { return LoadIcon("dog"); }
-		}
-	}
-}
diff --git a/OpenRa.TechTreeTest/Form1.cs b/OpenRa.TechTreeTest/Form1.cs
index b6bb4b7686..8ae429846d 100644
--- a/OpenRa.TechTreeTest/Form1.cs
+++ b/OpenRa.TechTreeTest/Form1.cs
@@ -22,25 +22,25 @@ namespace OpenRa.TechTreeTest
 		{
 			buildableItems.Controls.Clear();
 
-			foreach (IRAUnit b in techTree.BuildableItems)
+			foreach (Item b in techTree.BuildableItems)
 			{
 				PictureBox box = new PictureBox();
 				box.SizeMode = PictureBoxSizeMode.AutoSize;
 				box.Image = b.Icon;
 
-				toolTip1.SetToolTip(box, b.Tag + "\n" + b.Owner.ToString());
+				toolTip1.SetToolTip(box, b.Tooltip);
 
 				buildableItems.Controls.Add(box);
 
-				IRAUnit k = b;
+				Item k = b;
 
 				box.Click += delegate { Build(k); };
 			}
 		}
 
-		void Build(IRAUnit b)
+		void Build(Item b)
 		{
-			techTree.Build(b.Tag);
+			techTree.Build(b.tag);
 			RefreshList();
 		}
 	}
diff --git a/OpenRa.TechTreeTest/IRAUnit.cs b/OpenRa.TechTreeTest/IRAUnit.cs
deleted file mode 100644
index f0f35db98d..0000000000
--- a/OpenRa.TechTreeTest/IRAUnit.cs
+++ /dev/null
@@ -1,19 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Drawing;
-namespace OpenRa.TechTreeTest
-{
-	interface IRAUnit
-	{
-		bool Buildable { get; }
-		void CheckPrerequisites(IEnumerable<string> units, Race currentRace);
-		string FriendlyName { get; }
-		Bitmap Icon { get; }
-		Race Owner { get; set; }
-		string[] Prerequisites { get; set; }
-		bool ShouldMakeBuildable(IEnumerable<string> units);
-		bool ShouldMakeUnbuildable(IEnumerable<string> units);
-		string Tag { get; }
-		int TechLevel { get; set; }
-	}
-}
diff --git a/OpenRa.TechTreeTest/Item.cs b/OpenRa.TechTreeTest/Item.cs
new file mode 100644
index 0000000000..f50b6e1099
--- /dev/null
+++ b/OpenRa.TechTreeTest/Item.cs
@@ -0,0 +1,123 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Drawing;
+using OpenRa.FileFormats;
+using System.IO;
+
+namespace OpenRa.TechTreeTest
+{
+	class Item
+	{
+		public Item(string tag, string friendlyName, IniSection section, bool isStructure)
+		{
+			this.tag = tag;
+			this.friendlyName = friendlyName;
+
+			owner = ParseOwner(section);
+			techLevel = ParseTechLevel(section);
+			prerequisites = ParsePrerequisites(section);
+		}
+
+		static int ParseTechLevel(IniSection section)
+		{
+			return int.Parse(section.GetValue("TechLevel", "-1"));
+		}
+
+		static string[] ParsePrerequisites(IniSection section)
+		{
+			return section.GetValue("Prerequisite", "").ToUpper().Split(
+				new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+		}
+
+		static Race ParseOwner(IniSection section)
+		{
+			if (section.GetValue("DoubleOwned", "No") == "Yes")
+				return Race.Allies | Race.Soviet;
+
+			Race race = Race.None;
+			string[] frags = section.GetValue("Owner", "").Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
+
+			foreach (string s in frags)
+				race |= (Race)Enum.Parse(typeof(Race), s, true);
+
+			return race;
+		}
+
+		public readonly string tag, friendlyName;
+		readonly int techLevel;
+		readonly Race owner;
+		readonly string[] prerequisites;
+
+		bool ShouldMakeBuildable(IEnumerable<string> buildings)
+		{
+			if (techLevel < 0)
+				return false;
+
+			if (prerequisites.Length == 0)
+				return true;
+
+			List<string> p = new List<string>(prerequisites);
+			foreach (string b in buildings)
+				p.Remove(b);
+
+			return p.Count == 0;
+		}
+
+		bool ShouldMakeUnbuildable(IEnumerable<string> buildings)
+		{
+			if (prerequisites.Length == 0)
+				return false;
+
+			List<string> p = new List<string>(prerequisites);
+			foreach (string b in buildings)
+				p.Remove(b);
+
+			return p.Count == prerequisites.Length;
+		}
+
+		public void CheckPrerequisites(IEnumerable<string> buildings, Race currentRace)
+		{
+			if ((canBuild && ShouldMakeUnbuildable(buildings)) || !((owner & currentRace) == currentRace))
+				canBuild = false;
+			else if (!canBuild && ShouldMakeBuildable(buildings))
+				canBuild = true;
+		}
+
+		bool canBuild;
+		public bool CanBuild { get { return canBuild; } }
+
+		Bitmap icon;
+		public Bitmap Icon
+		{
+			get { return icon ?? (icon = LoadIcon(tag)); }
+		}
+
+		static Package package = new Package("../../../hires.mix");
+		static Palette palette = new Palette(File.OpenRead("../../../temperat.pal"));
+
+		static Bitmap LoadIcon(string tag)
+		{
+			string filename = tag + "icon.shp";
+
+			try
+			{
+				Stream s = package.GetContent(filename);
+				ShpReader reader = new ShpReader(s);
+				foreach (ImageHeader h in reader)
+					return BitmapBuilder.FromBytes(h.Image, reader.Width, reader.Height, palette);
+
+				return null;
+			}
+			catch (FileNotFoundException) { return LoadIcon("dog"); }
+		}
+
+		public string Tooltip
+		{
+			get
+			{
+				return string.Format("{0} ({1})\n{2}", friendlyName, tag, owner);
+			}
+		}
+	}
+}
diff --git a/OpenRa.TechTreeTest/OpenRa.TechTreeTest.csproj b/OpenRa.TechTreeTest/OpenRa.TechTreeTest.csproj
index 904c370ee4..dbc18e665f 100644
--- a/OpenRa.TechTreeTest/OpenRa.TechTreeTest.csproj
+++ b/OpenRa.TechTreeTest/OpenRa.TechTreeTest.csproj
@@ -36,14 +36,13 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="Building.cs" />
+    <Compile Include="Item.cs" />
     <Compile Include="Form1.cs">
       <SubType>Form</SubType>
     </Compile>
     <Compile Include="Form1.Designer.cs">
       <DependentUpon>Form1.cs</DependentUpon>
     </Compile>
-    <Compile Include="IRAUnit.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <EmbeddedResource Include="Form1.resx">
@@ -68,8 +67,8 @@
       <DependentUpon>Settings.settings</DependentUpon>
       <DesignTimeSharedInput>True</DesignTimeSharedInput>
     </Compile>
+    <Compile Include="Race.cs" />
     <Compile Include="TechTree.cs" />
-    <Compile Include="Unit.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRa.FileFormats\OpenRa.FileFormats.csproj">
diff --git a/OpenRa.TechTreeTest/Race.cs b/OpenRa.TechTreeTest/Race.cs
new file mode 100644
index 0000000000..f5a7756e74
--- /dev/null
+++ b/OpenRa.TechTreeTest/Race.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace OpenRa.TechTreeTest
+{
+	[Flags]
+	public enum Race
+	{
+		None = 0,
+		Allies = 1,
+		Soviet = 2
+	}
+}
diff --git a/OpenRa.TechTreeTest/TechTree.cs b/OpenRa.TechTreeTest/TechTree.cs
index 013666c62e..dc62b38ef7 100644
--- a/OpenRa.TechTreeTest/TechTree.cs
+++ b/OpenRa.TechTreeTest/TechTree.cs
@@ -9,84 +9,57 @@ namespace OpenRa.TechTreeTest
 {
 	class TechTree
 	{
-		Dictionary<string, IRAUnit> units = new Dictionary<string, IRAUnit>();
+		Dictionary<string, Item> objects = new Dictionary<string, Item>();
 		public ICollection<string> built = new List<string>();
+
 		readonly Race currentRace;
 
 		public TechTree(Race race)
 		{
 			this.currentRace = race;
-			LoadBuildings();
-			LoadUnits();
 			LoadRules();
 
 			built.Add("FACT");
 			CheckAll();
 		}
 
+		static IEnumerable<T> Concat<T>(IEnumerable<T> one, IEnumerable<T> two)
+		{
+			foreach (T t in one)
+				yield return t;
+			foreach (T t in two)
+				yield return t;
+		}
+
+		IEnumerable<Tuple<string, string, bool>> Lines(string filename, bool param)
+		{
+			Regex pattern = new Regex(@"^(\w+),([\w ]+)$");
+			foreach (string s in File.ReadAllLines(filename))
+			{
+				Match m = pattern.Match(s);
+				if (m == null || !m.Success)
+					continue;
+
+				yield return new Tuple<string, string, bool>(
+					m.Groups[1].Value, m.Groups[2].Value, param);
+			}
+		}
+
 		void LoadRules()
 		{
-			IniFile rulesFile;
-			rulesFile = new IniFile(File.OpenRead("../../../rules.ini"));
-			foreach (string key in units.Keys)
-			{
-				IniSection section = rulesFile.GetSection(key);
-				IRAUnit b = units[key];
-				string s = section.GetValue("Prerequisite", "").ToUpper();
-				b.Prerequisites = s.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-				b.TechLevel = int.Parse(section.GetValue("TechLevel", "-1"));
-				s = section.GetValue("Owner", "");
-				
-				if (string.IsNullOrEmpty(s))
-				{
-					s = section.GetValue("DoubleOwned", "No");
-					if (s.Equals("Yes", StringComparison.InvariantCultureIgnoreCase))
-						b.Owner = Race.Allies | Race.Soviet;
-					else
-						b.Owner = Race.None;
-					continue;
-				}
-				
-				if (s.Equals("Both", StringComparison.InvariantCultureIgnoreCase))
-				{
-					b.Owner = Race.Allies | Race.Soviet;
-					continue;
-				}
-				
-				string[] frags = s.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
-				if (frags.Length > 1)
-					b.Owner = Race.Allies | Race.Soviet;
-				else
-					b.Owner = (Race)Enum.Parse(typeof(Race), frags[0], true);
-			}
-		}
+			IniFile rulesFile = new IniFile(File.OpenRead("../../../rules.ini"));
+			IEnumerable<Tuple<string, string, bool>> definitions = Concat(
+				Lines("../../../buildings.txt", true),
+				Lines("../../../units.txt", false));
 
-		void LoadBuildings()
-		{
-			foreach (string line in File.ReadAllLines("../../../buildings.txt"))
-			{
-				Regex pattern = new Regex(@"^(\w+),([\w ]+)$");
-				Match m = pattern.Match(line);
-				if (!m.Success) continue;
-				units.Add(m.Groups[1].Value, new Building(m.Groups[1].Value, m.Groups[2].Value));
-			}
-		}
-
-		void LoadUnits()
-		{
-			foreach (string line in File.ReadAllLines("../../../units.txt"))
-			{
-				Regex pattern = new Regex(@"^(\w+),([\w ]+)$");
-				Match m = pattern.Match(line);
-				if (!m.Success) continue;
-				units.Add(m.Groups[1].Value, new Unit(m.Groups[1].Value, m.Groups[2].Value));
-			}
+			foreach (Tuple<string, string, bool> p in definitions)
+				objects.Add(p.a, new Item(p.a, p.b, rulesFile.GetSection(p.a), p.c));
 		}
 
 		public bool Build(string key)
 		{
-			IRAUnit b = units[key];
-			if (!b.Buildable) return false;
+			Item b = objects[key];
+			if (!b.CanBuild) return false;
 			built.Add(key);
 			CheckAll();
 			return true;
@@ -94,7 +67,7 @@ namespace OpenRa.TechTreeTest
 
 		public bool Unbuild(string key)
 		{
-			IRAUnit b = units[key];
+			Item b = objects[key];
 			if (!built.Contains(key)) return false;
 			built.Remove(key);
 			CheckAll();
@@ -103,16 +76,16 @@ namespace OpenRa.TechTreeTest
 
 		void CheckAll()
 		{
-			foreach (IRAUnit unit in units.Values)
+			foreach (Item unit in objects.Values)
 				unit.CheckPrerequisites(built, currentRace);
 		}
 
-		public IEnumerable<IRAUnit> BuildableItems
+		public IEnumerable<Item> BuildableItems
 		{
 			get
 			{
-				foreach (IRAUnit b in units.Values)
-					if (b.Buildable)
+				foreach (Item b in objects.Values)
+					if (b.CanBuild)
 						yield return b;
 			}
 		}
diff --git a/OpenRa.TechTreeTest/Unit.cs b/OpenRa.TechTreeTest/Unit.cs
deleted file mode 100644
index 2fe00b74fa..0000000000
--- a/OpenRa.TechTreeTest/Unit.cs
+++ /dev/null
@@ -1,111 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-using System.Drawing;
-using OpenRa.FileFormats;
-using System.IO;
-
-namespace OpenRa.TechTreeTest
-{
-	class Unit : IRAUnit
-	{
-		bool buildable;
-		public bool Buildable { get { return buildable; } }
-
-		public void CheckPrerequisites(IEnumerable<string> units, Race currentRace)
-		{
-			if ((buildable && ShouldMakeUnbuildable(units)) || !((owner & currentRace) == currentRace))
-				buildable = false;
-			else if (!buildable && ShouldMakeBuildable(units))
-				buildable = true; ;
-		}
-
-		readonly string friendlyName; 
-		public string FriendlyName { get { return friendlyName; } }
-
-		Bitmap icon;
-		public Bitmap Icon
-		{
-			get { return icon ?? (icon = LoadIcon(tag)); }
-		}
-
-		static Package package = new Package("../../../hires.mix");
-		static Palette palette = new Palette(File.OpenRead("../../../temperat.pal"));
-
-		static Bitmap LoadIcon(string tag)
-		{
-			string filename = tag + "icon.shp";
-
-			try
-			{
-				Stream s = package.GetContent(filename);
-				ShpReader reader = new ShpReader(s);
-				foreach (ImageHeader h in reader)
-					return BitmapBuilder.FromBytes(h.Image, reader.Width, reader.Height, palette);
-
-				return null;
-			}
-			catch (FileNotFoundException) { return LoadIcon("dog"); }
-		}
-
-		Race owner;
-		public Race Owner
-		{
-			get { return owner; }
-			set { owner = value; }
-		}
-
-		string[] prerequisites;
-		public string[] Prerequisites
-		{
-			get { return prerequisites; }
-			set { prerequisites = value; }
-		}
-
-		public bool ShouldMakeBuildable(IEnumerable<string> units)
-		{
-			if (techLevel > 10 || techLevel < 0)
-				return false;
-
-			if (prerequisites.Length == 0)
-				return true;
-
-			List<string> p = new List<string>(prerequisites);
-			foreach (string b in units)
-				p.Remove(b);
-
-			return p.Count == 0;
-		}
-
-		public bool ShouldMakeUnbuildable(IEnumerable<string> units)
-		{
-			if (prerequisites.Length == 0)
-				return false;
-
-			List<string> p = new List<string>(prerequisites);
-			foreach (string b in units)
-				p.Remove(b);
-
-			return p.Count == prerequisites.Length;
-		}
-
-		readonly string tag;
-		public string Tag
-		{
-			get { return tag; }
-		}
-
-		int techLevel;
-		public int TechLevel
-		{
-			get { return techLevel; }
-			set { techLevel = value; }
-		}
-
-		public Unit(string tag, string friendlyName)
-		{
-			this.friendlyName = friendlyName;
-			this.tag = tag;
-		}
-	}
-}