My electrical contractor has finished the rough-in wiring for my timber frame home (wrapped in SIPs). Because I have no sub-floor or attic, there are several wires that were placed directly through a timber floor joist or roof purlin. What is the electrical requirement for mounting the fixture to the joist/purlin? Does there have to be an electrical box mounted to the wooden structure before the fixture can be attached, or can the fixture be wired directly to the joist/purlin with no box?
Many thanks.

A box is always needed in my region. The box can be set into the timber, bit of a pain if you're working on the underside overhead, better to do in the shop...

As Mark says, you'll need a box to meet code. But your electrical contractor should know exactly what's required in your area. Like Mark, we like to recess the box back into the timber. There are low-profile boxes available that make this less painful. CB.