One of my players wants to maintain a ward in his apartment (as all good wizards should) and we're both stumbling around a little in the dark. How might the (admittedly feeble) threshold affect his ward? The definition of a ward mentions the threshold a few times, and we get the impression in the books that an existing threshold enhances a ward. At the very least, YS states that a threshold defines the area (eg, a single ward wouldn't cover two distinct apartments without notably increasing the difficulty).

I currently see three possibly distinct interactions:

• The strengths of a ward and a threshold are additive (as opposed to sitting side-by-side).
• The threshold helps or hampers the creation of the ward.
• "Ward" can be substituted for "threshold" elsewhere in the book.

Is there anything definite for or against these points? Maybe we're just making it more complicated than it is.