Building assemblies create cost of goods credits

Figured it out, I think, the debits are countered with credits against stock. Might be better to call the account something else... building assemblies is not purchases

Thanks for getting in touch with the Community, jaapkrijger.

The amount in the Cost of Goods Sold (COGS) accounts increases once an item is sold, instead of when an assembly is built.

Normally, inventory COGS is only affected when you sell inventory items on invoices or sales receipts. If you sell an item, you can run your Transaction Journal report for the invoice/sales receipt to see the Sales/Accounts Receivable transaction. Here, you'll notice your Inventory/COGS transactions which credits the Inventory Asset account and debits your COGS.

If you sell inventory that you don't have, you can force the next bills, checks, or credit card charges to adjust the Inventory Asset and COGs accounts. The amount on each side of your Inventory/COGS transactions are as follows: Number of Items Sold x Average Cost of Item
 

I've included a detailed resource about working with COGS which may come in handy moving forward: Understand inventory assets & cost of goods sold tracking

Please feel welcome to send a reply if there's any questions. Have a wonderful day!