What an outstanding piece of writing. There's so many things I like about this story. The measured, simple sentences, the house as third character - dark and cold and waiting, Justin's quiet and mature command of the situation, Brian's fear and anger - so near the surface, yet tamped down until the brief flare up at the end. And finally, how they find warmth and home in each other.
If it was intentional, the north-facing studio windows was a nice touch. In winter, the room would have little to no sunlight and thus be another reason, a vital one really, for Justin not to belong there.