I only remember one scene and it had two guys strapped to individual metal tables that look like something from a morgue. The room was made up like an operating room but was dank and dark. The disfigured bad guy had one of the tables rigged to heat up and one of the guys is burned to the table; when he finally tries to get up it rips his skin. If I remember right the house was in the middle of the woods. Was on IFC or sundance channel but can't remember the name.
See if this fits: Dante Tomaselli's Torture Chamber from 2012 about a disfigured boy who tortures people with the help of local children in a mansion's dungeon. One of the medieval torture devices is a metal slab called the Stove which burns people as you've described; you can see people strapped to it in this trailer (and also the mansion, which seems to be near the woods).