Hi Tim and Thane,
Metal does play an important part in building construction. For example nails have been around for a very long time and at this time of year we are reminded that the Romans had developed this technology to a fine art and had put it to a whole number of uses.
Richard Harris likes to pose the general essay topic - "Metal has no place in timber building construction - discuss" at least once in The Bournemouth University / Weald and Downland Masters degree course in Timber Building Conservation.
Many repairs are made using metal to preserve as much original timber fabric as possible in old buildings but there is a thin line between its usefulness and its intrusion into the wooden art form.
Regards
Ken Hume