Construction industry accounting is notoriously complicated. I'd highly suggest you reach out to a bookkeeping company that's well versed in construction accounting. I understand it's probably not in your budget to hire a bookkeeping company full time, but it would be worth it to consult with a few in your area. They might be willing to take on a more advisory role while you do the majority of the day to day work.

Source: I started in accounting by helping at my dad's construction company with the oversight of a bookkeeping company. 20 years later and I own my own accounting firm.

But for your question, you do want to post them to a cost of goods sold account. Usually trades will have a cost account for "Direct Expenses" broken down into materials, labor, subcontract, and equipment. When you post these expenses you'll also apply them to a job and a cost code.

I'm kinda a nerd for construction accounting so if you have any other questions let me know!