You can find and place the sawmill on your castle building screen. To use it, you will have to turn it on, connecting it to your Castle Heart. To power up the Castle Heart, you will need to add more Blood Essence, which will power up all the machinery at the same time, including the sawmill.
Once it's powered up, you'll need to feed it using wood to get wood planks. There is a recipe log for each machinery, which will let you know what materials are needed to craft each item, and when you have the necessary materials, you can use them in the machinery to get the item.
To upgrade the Sawmill, you'll need to check the three panels at the top of the Sawmill window after interacting with them, to access the objectives you'll need to complete to get the upgrade.
This is everything you need to know about how to unlock the sawmill in V Rising and now that we are done, we hope that you will get your sawmill quickly, so that you can get a lot of use out of it.