diff --git a/src/client/graphics/layers/StructureLayer.ts b/src/client/graphics/layers/StructureLayer.ts
index ae9119509..ff7b1be73 100644
--- a/src/client/graphics/layers/StructureLayer.ts
+++ b/src/client/graphics/layers/StructureLayer.ts
@@ -8,10 +8,12 @@ import missileSiloIcon from "../../../../resources/images/MissileSiloUnit.png";
 import shieldIcon from "../../../../resources/images/ShieldIcon.png";
 import cityIcon from "../../../../resources/images/CityIcon.png";
 import { GameView, UnitView } from "../../../core/game/GameView";
-import { Cell, Unit, UnitType } from "../../../core/game/Game";
+import { Cell, UnitType } from "../../../core/game/Game";
 import { GameUpdateType } from "../../../core/game/GameUpdates";
 import { euclDistFN } from "../../../core/game/GameMap";
 
+const underConstructionColor = colord({ r: 150, g: 150, b: 150 });
+
 interface UnitRenderConfig {
   icon: string;
   borderRadius: number;
@@ -48,10 +50,7 @@ export class StructureLayer implements Layer {
     },
   };
 
-  constructor(
-    private game: GameView,
-    private eventBus: EventBus,
-  ) {
+  constructor(private game: GameView, private eventBus: EventBus) {
     this.theme = game.config().theme();
     this.loadIconData();
   }
@@ -73,11 +72,11 @@ export class StructureLayer implements Layer {
           0,
           0,
           tempCanvas.width,
-          tempCanvas.height,
+          tempCanvas.height
         );
         this.unitIcons.set(unitType, iconData);
         console.log(
-          `icond data width height: ${iconData.width}, ${iconData.height}`,
+          `icond data width height: ${iconData.width}, ${iconData.height}`
         );
       };
     });
@@ -90,9 +89,9 @@ export class StructureLayer implements Layer {
   tick() {
     this.game
       .updatesSinceLastTick()
-      [
-        GameUpdateType.Unit
-      ].forEach((u) => this.handleUnitRendering(this.game.unit(u.id)));
+      [GameUpdateType.Unit].forEach((u) =>
+        this.handleUnitRendering(this.game.unit(u.id))
+      );
   }
 
   init() {
@@ -114,7 +113,7 @@ export class StructureLayer implements Layer {
       -this.game.width() / 2,
       -this.game.height() / 2,
       this.game.width(),
-      this.game.height(),
+      this.game.height()
     );
   }
 
@@ -123,7 +122,7 @@ export class StructureLayer implements Layer {
   }
 
   private handleUnitRendering(unit: UnitView) {
-    const unitType = unit.type();
+    const unitType = unit.constructionType() ?? unit.type();
     if (!this.isUnitTypeSupported(unitType)) return;
 
     const config = this.unitConfigs[unitType];
@@ -134,7 +133,7 @@ export class StructureLayer implements Layer {
     // Clear previous rendering
     for (const tile of this.game.bfs(
       unit.tile(),
-      euclDistFN(unit.tile(), config.borderRadius),
+      euclDistFN(unit.tile(), config.borderRadius)
     )) {
       this.clearCell(new Cell(this.game.x(tile), this.game.y(tile)));
     }
@@ -146,23 +145,27 @@ export class StructureLayer implements Layer {
     // Draw border and territory
     for (const tile of this.game.bfs(
       unit.tile(),
-      euclDistFN(unit.tile(), config.borderRadius),
+      euclDistFN(unit.tile(), config.borderRadius)
     )) {
       this.paintCell(
         new Cell(this.game.x(tile), this.game.y(tile)),
-        this.theme.borderColor(unit.owner().info()),
-        255,
+        unit.type() == UnitType.Construction
+          ? underConstructionColor
+          : this.theme.borderColor(unit.owner().info()),
+        255
       );
     }
 
     for (const tile of this.game.bfs(
       unit.tile(),
-      euclDistFN(unit.tile(), config.territoryRadius),
+      euclDistFN(unit.tile(), config.territoryRadius)
     )) {
       this.paintCell(
         new Cell(this.game.x(tile), this.game.y(tile)),
-        this.theme.territoryColor(unit.owner().info()),
-        130,
+        unit.type() == UnitType.Construction
+          ? underConstructionColor
+          : this.theme.territoryColor(unit.owner().info()),
+        130
       );
     }
 
@@ -178,8 +181,12 @@ export class StructureLayer implements Layer {
     startY: number,
     width: number,
     height: number,
-    unit: UnitView,
+    unit: UnitView
   ) {
+    let color = this.theme.borderColor(unit.owner().info());
+    if (unit.type() == UnitType.Construction) {
+      color = underConstructionColor;
+    }
     for (let y = 0; y < height; y++) {
       for (let x = 0; x < width; x++) {
         const iconIndex = (y * width + x) * 4;
@@ -195,11 +202,7 @@ export class StructureLayer implements Layer {
             targetY >= 0 &&
             targetY < this.game.height()
           ) {
-            this.paintCell(
-              new Cell(targetX, targetY),
-              this.theme.borderColor(unit.owner().info()),
-              alpha,
-            );
+            this.paintCell(new Cell(targetX, targetY), color, alpha);
           }
         }
       }
diff --git a/src/client/graphics/layers/UnitLayer.ts b/src/client/graphics/layers/UnitLayer.ts
index 2e36696d5..2afc300bd 100644
--- a/src/client/graphics/layers/UnitLayer.ts
+++ b/src/client/graphics/layers/UnitLayer.ts
@@ -1,7 +1,6 @@
 import { Colord } from "colord";
 import { Theme } from "../../../core/configuration/Config";
 import { Unit, UnitType, Player } from "../../../core/game/Game";
-import { UnitUpdate } from "../../../core/game/GameUpdates";
 import { Layer } from "./Layer";
 import { EventBus } from "../../../core/EventBus";
 import { AlternateViewEvent } from "../../InputHandler";
diff --git a/src/core/configuration/DefaultConfig.ts b/src/core/configuration/DefaultConfig.ts
index 52aeb4dbf..5d7d75fe6 100644
--- a/src/core/configuration/DefaultConfig.ts
+++ b/src/core/configuration/DefaultConfig.ts
@@ -109,6 +109,7 @@ export class DefaultConfig implements Config {
               Math.pow(2, p.units(UnitType.Port).length) * 250_000
             ),
           territoryBound: true,
+          constructionDuration: 2 * 10,
         };
       case UnitType.AtomBomb:
         return {
@@ -139,6 +140,7 @@ export class DefaultConfig implements Config {
         return {
           cost: () => 1_000_000,
           territoryBound: true,
+          constructionDuration: 10 * 10,
         };
       case UnitType.DefensePost:
         return {
@@ -148,6 +150,7 @@ export class DefaultConfig implements Config {
               (p.units(UnitType.DefensePost).length + 1) * 50_000
             ),
           territoryBound: true,
+          constructionDuration: 5 * 10,
         };
       case UnitType.City:
         return {
@@ -157,6 +160,12 @@ export class DefaultConfig implements Config {
               Math.pow(2, p.units(UnitType.City).length) * 125_000
             ),
           territoryBound: true,
+          constructionDuration: 2 * 10,
+        };
+      case UnitType.Construction:
+        return {
+          cost: () => 0,
+          territoryBound: true,
         };
       default:
         assertNever(type);
diff --git a/src/core/configuration/DevConfig.ts b/src/core/configuration/DevConfig.ts
index 93f42456d..717a8c3ed 100644
--- a/src/core/configuration/DevConfig.ts
+++ b/src/core/configuration/DevConfig.ts
@@ -45,10 +45,10 @@ export class DevConfig extends DefaultConfig {
   //     return 5000
   // }
 
-  // numBots(): number {
-  //   return 0;
-  // }
-  // spawnNPCs(): boolean {
-  //   return false;
-  // }
+  //   numBots(): number {
+  //     return 0;
+  //   }
+  //   spawnNPCs(): boolean {
+  //     return false;
+  //   }
 }
diff --git a/src/core/execution/ConstructionExecution.ts b/src/core/execution/ConstructionExecution.ts
new file mode 100644
index 000000000..0e5ff2048
--- /dev/null
+++ b/src/core/execution/ConstructionExecution.ts
@@ -0,0 +1,122 @@
+import { consolex } from "../Consolex";
+import {
+  Cell,
+  Execution,
+  Game,
+  Player,
+  Unit,
+  PlayerID,
+  UnitType,
+  Tick,
+} from "../game/Game";
+import { TileRef } from "../game/GameMap";
+import { CityExecution } from "./CityExecution";
+import { DefensePostExecution } from "./DefensePostExecution";
+import { MirvExecution } from "./MIRVExecution";
+import { MissileSiloExecution } from "./MissileSiloExecution";
+import { NukeExecution } from "./NukeExecution";
+import { PortExecution } from "./PortExecution";
+import { WarshipExecution } from "./WarshipExecution";
+
+export class ConstructionExecution implements Execution {
+  private player: Player;
+  private construction: Unit;
+  private active: boolean = true;
+  private mg: Game;
+
+  private ticksUntilComplete: Tick;
+
+  constructor(
+    private ownerId: PlayerID,
+    private tile: TileRef,
+    private constructionType: UnitType
+  ) {}
+
+  init(mg: Game, ticks: number): void {
+    this.mg = mg;
+    this.player = mg.player(this.ownerId);
+  }
+
+  tick(ticks: number): void {
+    if (this.construction == null) {
+      const info = this.mg.unitInfo(this.constructionType);
+      if (info.constructionDuration == null) {
+        this.completeConstruction();
+        this.active = false;
+        return;
+      }
+      const spawnTile = this.player.canBuild(this.constructionType, this.tile);
+      if (spawnTile == false) {
+        consolex.warn(`cannot build ${UnitType.Construction}`);
+        this.active = false;
+        return;
+      }
+      this.construction = this.player.buildUnit(
+        UnitType.Construction,
+        0,
+        spawnTile
+      );
+      this.construction.setConstructionType(this.constructionType);
+      this.ticksUntilComplete = info.constructionDuration;
+      return;
+    }
+
+    if (!this.construction.isActive()) {
+      this.active = false;
+      return;
+    }
+
+    if (this.ticksUntilComplete == 0) {
+      this.player = this.construction.owner();
+      this.construction.delete(false);
+      this.completeConstruction();
+      this.active = false;
+      return;
+    }
+    this.ticksUntilComplete--;
+  }
+
+  private completeConstruction() {
+    const player = this.player;
+    switch (this.constructionType) {
+      case UnitType.AtomBomb:
+      case UnitType.HydrogenBomb:
+        this.mg.addExecution(
+          new NukeExecution(this.constructionType, player.id(), this.tile)
+        );
+        break;
+      case UnitType.MIRV:
+        this.mg.addExecution(new MirvExecution(player.id(), this.tile));
+        break;
+      case UnitType.Warship:
+        this.mg.addExecution(new WarshipExecution(player.id(), this.tile));
+        break;
+      case UnitType.Port:
+        this.mg.addExecution(new PortExecution(player.id(), this.tile));
+        break;
+      case UnitType.MissileSilo:
+        this.mg.addExecution(new MissileSiloExecution(player.id(), this.tile));
+        break;
+      case UnitType.DefensePost:
+        this.mg.addExecution(new DefensePostExecution(player.id(), this.tile));
+        break;
+      case UnitType.City:
+        this.mg.addExecution(new CityExecution(player.id(), this.tile));
+        break;
+      default:
+        throw Error(`unit type ${this.constructionType} not supported`);
+    }
+  }
+
+  owner(): Player {
+    return null;
+  }
+
+  isActive(): boolean {
+    return this.active;
+  }
+
+  activeDuringSpawnPhase(): boolean {
+    return false;
+  }
+}
diff --git a/src/core/execution/ExecutionManager.ts b/src/core/execution/ExecutionManager.ts
index 9564b3f8f..49a6e825f 100644
--- a/src/core/execution/ExecutionManager.ts
+++ b/src/core/execution/ExecutionManager.ts
@@ -38,6 +38,7 @@ import { DefensePostExecution } from "./DefensePostExecution";
 import { CityExecution } from "./CityExecution";
 import { TileRef } from "../game/GameMap";
 import { MirvExecution } from "./MIRVExecution";
+import { ConstructionExecution } from "./ConstructionExecution";
 
 export class Executor {
   // private random = new PseudoRandom(999)
@@ -106,47 +107,11 @@ export class Executor {
       case "troop_ratio":
         return new SetTargetTroopRatioExecution(intent.player, intent.ratio);
       case "build_unit":
-        switch (intent.unit) {
-          case UnitType.AtomBomb:
-          case UnitType.HydrogenBomb:
-            return new NukeExecution(
-              intent.unit,
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.MIRV:
-            return new MirvExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.Warship:
-            return new WarshipExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.Port:
-            return new PortExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.MissileSilo:
-            return new MissileSiloExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.DefensePost:
-            return new DefensePostExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          case UnitType.City:
-            return new CityExecution(
-              intent.player,
-              this.mg.ref(intent.x, intent.y)
-            );
-          default:
-            throw Error(`unit type ${intent.unit} not supported`);
-        }
+        return new ConstructionExecution(
+          intent.player,
+          this.mg.ref(intent.x, intent.y),
+          intent.unit
+        );
       default:
         throw new Error(`intent type ${intent} not found`);
     }
diff --git a/src/core/execution/FakeHumanExecution.ts b/src/core/execution/FakeHumanExecution.ts
index 5ddf7bbea..fb73b22a9 100644
--- a/src/core/execution/FakeHumanExecution.ts
+++ b/src/core/execution/FakeHumanExecution.ts
@@ -29,6 +29,7 @@ import { AllianceRequestReplyExecution } from "./alliance/AllianceRequestReplyEx
 import { closestTwoTiles } from "./Util";
 import { calculateBoundingBox, simpleHash } from "../Util";
 import { andFN, manhattanDistFN, TileRef } from "../game/GameMap";
+import { ConstructionExecution } from "./ConstructionExecution";
 
 export class FakeHumanExecution implements Execution {
   private firstMove = true;
@@ -304,14 +305,16 @@ export class FakeHumanExecution implements Execution {
       );
       if (oceanTiles.length > 0) {
         const buildTile = this.random.randElement(oceanTiles);
-        this.mg.addExecution(new PortExecution(this.player.id(), buildTile));
+        this.mg.addExecution(
+          new ConstructionExecution(this.player.id(), buildTile, UnitType.Port)
+        );
       }
       return;
     }
     this.maybeSpawnStructure(
       UnitType.City,
       2,
-      (t) => new CityExecution(this.player.id(), t)
+      (t) => new ConstructionExecution(this.player.id(), t, UnitType.City)
     );
     if (this.maybeSpawnWarship()) {
       return;
@@ -319,7 +322,8 @@ export class FakeHumanExecution implements Execution {
     this.maybeSpawnStructure(
       UnitType.MissileSilo,
       1,
-      (t) => new MissileSiloExecution(this.player.id(), t)
+      (t) =>
+        new ConstructionExecution(this.player.id(), t, UnitType.MissileSilo)
     );
   }
 
@@ -369,7 +373,13 @@ export class FakeHumanExecution implements Execution {
         consolex.warn("cannot spawn destroyer");
         return false;
       }
-      this.mg.addExecution(new WarshipExecution(this.player.id(), targetTile));
+      this.mg.addExecution(
+        new ConstructionExecution(
+          this.player.id(),
+          targetTile,
+          UnitType.Warship
+        )
+      );
       return true;
     }
     return false;
diff --git a/src/core/game/Game.ts b/src/core/game/Game.ts
index d12497f74..371c3e905 100644
--- a/src/core/game/Game.ts
+++ b/src/core/game/Game.ts
@@ -58,6 +58,7 @@ export interface UnitInfo {
   territoryBound: boolean;
   maxHealth?: number;
   damage?: number;
+  constructionDuration?: number;
 }
 
 export enum UnitType {
@@ -73,6 +74,7 @@ export enum UnitType {
   City = "City",
   MIRV = "MIRV",
   MIRVWarhead = "MIRV Warhead",
+  Construction = "Construction",
 }
 
 export enum Relation {
@@ -187,6 +189,10 @@ export interface Unit {
   setTroops(troops: number): void;
   delete(displayerMessage?: boolean): void;
 
+  // Only for Construction type
+  constructionType(): UnitType | null;
+  setConstructionType(type: UnitType): void;
+
   // Updates
   toUpdate(): UnitUpdate;
 }
diff --git a/src/core/game/GameImpl.ts b/src/core/game/GameImpl.ts
index ea6114a11..9b76a45de 100644
--- a/src/core/game/GameImpl.ts
+++ b/src/core/game/GameImpl.ts
@@ -13,7 +13,6 @@ import {
   Nation,
   UnitType,
   UnitInfo,
-  AllPlayers,
   GameUpdates,
   TerrainType,
   EmojiMessage,
diff --git a/src/core/game/GameUpdates.ts b/src/core/game/GameUpdates.ts
index ad1c3eaf8..7bd89182a 100644
--- a/src/core/game/GameUpdates.ts
+++ b/src/core/game/GameUpdates.ts
@@ -67,6 +67,7 @@ export interface UnitUpdate {
   lastPos: MapPos;
   isActive: boolean;
   health?: number;
+  constructionType?: UnitType;
 }
 
 export interface PlayerUpdate {
diff --git a/src/core/game/GameView.ts b/src/core/game/GameView.ts
index 7b87026f5..bde421c9e 100644
--- a/src/core/game/GameView.ts
+++ b/src/core/game/GameView.ts
@@ -86,6 +86,9 @@ export class UnitView {
   health(): number {
     return this.data.health ?? 0;
   }
+  constructionType(): UnitType | undefined {
+    return this.data.constructionType;
+  }
 }
 
 export class PlayerView {
diff --git a/src/core/game/PlayerImpl.ts b/src/core/game/PlayerImpl.ts
index 97dac7417..42df4622d 100644
--- a/src/core/game/PlayerImpl.ts
+++ b/src/core/game/PlayerImpl.ts
@@ -580,15 +580,14 @@ export class PlayerImpl implements Player {
         return this.warshipSpawn(targetTile);
       case UnitType.Shell:
         return targetTile;
-      case UnitType.MissileSilo:
-        return this.landBasedStructureSpawn(targetTile);
-      case UnitType.DefensePost:
-        return this.landBasedStructureSpawn(targetTile);
       case UnitType.TransportShip:
         return this.transportShipSpawn(targetTile);
       case UnitType.TradeShip:
         return this.tradeShipSpawn(targetTile);
+      case UnitType.MissileSilo:
+      case UnitType.DefensePost:
       case UnitType.City:
+      case UnitType.Construction:
         return this.landBasedStructureSpawn(targetTile);
       default:
         assertNever(unitType);
diff --git a/src/core/game/UnitImpl.ts b/src/core/game/UnitImpl.ts
index 4429714c9..1cc90a682 100644
--- a/src/core/game/UnitImpl.ts
+++ b/src/core/game/UnitImpl.ts
@@ -12,6 +12,8 @@ export class UnitImpl implements Unit {
   private _health: number;
   private _lastTile: TileRef = null;
 
+  private _constructionType: UnitType = undefined;
+
   constructor(
     private _type: UnitType,
     private mg: GameImpl,
@@ -36,6 +38,7 @@ export class UnitImpl implements Unit {
       pos: { x: this.mg.x(this._tile), y: this.mg.y(this._tile) },
       lastPos: { x: this.mg.x(this._lastTile), y: this.mg.y(this._lastTile) },
       health: this.hasHealth() ? this._health : undefined,
+      constructionType: this._constructionType,
     };
   }
 
@@ -116,6 +119,21 @@ export class UnitImpl implements Unit {
     return this._active;
   }
 
+  constructionType(): UnitType | null {
+    if (this.type() != UnitType.Construction) {
+      throw new Error(`Cannot get construction type on ${this.type()}`);
+    }
+    return this._constructionType;
+  }
+
+  setConstructionType(type: UnitType): void {
+    if (this.type() != UnitType.Construction) {
+      throw new Error(`Cannot set construction type on ${this.type()}`);
+    }
+    this._constructionType = type;
+    this.mg.addUpdate(this.toUpdate());
+  }
+
   hash(): number {
     return this.tile() + simpleHash(this.type());
   }