Your Core AIC Area is the heart of your factory operations in Arknights Endfield. It’s where you’ll place most of your production buildings, distribute electricity across your base, and orchestrate your entire automation setup. The problem? Starting space is tight, and as your factory grows, you’ll quickly realize you need more room to work with.
Fortunately, expanding your Core AIC Area isn’t complicated once you know the steps. This guide walks you through unlocking expansions, managing upgrade costs, and utilizing the Depot Bus system to streamline your operations. If you’re looking for more ways to optimize your base, check out our Arknights Endfield guides hub for comprehensive coverage of all game systems.
You can play Arknights Endfield on PC via Epic Games, mobile through Google Play, or check the official website for updates and events.
Unlocking Area Expansion: The AIC Steward Quest
Before you can expand your Core AIC Area, you need to complete a specific quest called AIC Steward. This mission becomes available as you progress through the main storyline and develop your factory.
How to Start the AIC Steward Quest
- Open your Baker message interface
- Navigate to the Tasks tab
- Look for the message from Fiona the Comms Officer
- Read through her message about the AIC Steward developed by the Endfield R&D Center
- Complete the text prompt to trigger the quest
The quest itself is simple—just talk to the newly arrived AIC Steward to learn about area expansion options. Once completed, you’ll unlock the upgrade interface and gain access to expansion capabilities.
Finding the AIC Steward
After finishing the quest, the AIC Steward will appear on the southeastern side of your Core AIC Area. Interact with them to open the upgrade window, where you can manage both area expansions and Depot Bus construction.
Core AIC Area Upgrade Costs
Expanding your base requires Valley Stock Bills, the in-game currency you earn through various activities. Here’s the complete breakdown of upgrade costs:
Area Expansions
- Area Expansion I: 20,000 Valley Stock Bills
- Area Expansion II: 160,000 Valley Stock Bills
Depot Bus Upgrades
- Depot Bus I: 5,000 Valley Stock Bills
- Depot Bus II: 20,000 Valley Stock Bills
- Depot Bus III: 40,000 Valley Stock Bills
- Depot Bus IV: 80,000 Valley Stock Bills
- Depot Bus V: 160,000 Valley Stock Bills
- Depot Bus VI: 320,000 Valley Stock Bills
Important Note on Progression
You cannot build Depot Bus upgrades without proper area expansion. The two systems are interconnected, so plan your upgrades accordingly. Don’t sink all your currency into Depot Bus levels if you haven’t expanded your actual building space first.
If you’re also managing power output and production chains, balancing these currency investments becomes crucial. Make sure you’re generating enough Valley Stock Bills to support both expansion and operational needs.
Understanding the Depot Bus System
Once you meet the AIC Steward, you unlock the Depot Bus node in the Power section of your AIC Factory Plan. This unlocks two essential components: Depot Loader and Depot Unloader.
How Depot Loaders and Unloaders Work
Both structures must connect directly to the Depot Bus to function:
- Depot Loader: Submits items into the depot storage system
- Depot Unloader: Retrieves assigned items from the depot storage
Why the Depot Bus Matters
In the early game, you’re stuck routing everything through your central tower. This creates bottlenecks and limits how you can design your factory layout. The Depot Bus changes that by offering an alternative route for item storage and retrieval.
Instead of cramming everything around the central hub, you can spread production lines across your expanded area and use Depot Bus connections to manage logistics. This becomes especially valuable when you’re running complex production chains for character upgrades or crafting advanced materials.
Strategic Tips for Expansion
- Prioritize Area Expansion I early: That first 20k investment opens up significant breathing room. Don’t delay it if your factory feels cramped.
- Plan your Depot Bus placement: Think about where production chains will run before placing Depot Bus nodes. Poor placement means rebuilding later.
- Farm Valley Stock Bills consistently: Complete missions, sell excess materials at the Outpost, and optimize your production to generate steady income for upgrades.
- Balance expansion with power needs: More space means more buildings, which means higher energy demands. Make sure your Thermal Banks can handle the load.
- Consider team management alongside base building: While expanding your factory, don’t neglect team compositions and character builds for combat content.
For players just starting out, our reroll guide and gacha system breakdown can help you build a strong foundation. And if you’re diving into factory optimization, understanding stats and elemental reactions will give you an edge in both production and combat.
Additional Resources
Looking for more ways to enhance your experience? Check out:
- Best settings for optimal performance
- Redeem codes for free rewards
- Multiplayer and co-op guide
- Twitch Drops rewards
- Complete characters guide
- Switching Endministrators
Frequently Asked Questions
How do I unlock Core AIC Area expansion in Arknights Endfield?
Complete the AIC Steward quest by reading Fiona’s message in the Baker Tasks tab. After finishing the quest, the AIC Steward appears in the southeastern section of your Core AIC Area, where you can access expansion upgrades.
Can I build Depot Bus without expanding my Core AIC Area?
No, the two systems are linked. You need to invest in area expansions before you can fully utilize Depot Bus upgrades. Plan your Valley Stock Bill spending to accommodate both systems.
What’s the total cost to fully expand the Core AIC Area?
Area Expansions cost 20,000 and 160,000 Valley Stock Bills respectively (180,000 total). Depot Bus upgrades range from 5,000 to 320,000, totaling 625,000 across all six levels. Full expansion requires 805,000 Valley Stock Bills.
What’s the benefit of using the Depot Bus system?
The Depot Bus provides alternative logistics routes beyond the central tower, reducing bottlenecks and allowing more flexible factory layouts. This becomes essential for complex production chains and efficient resource management as your base grows.
