I am faux vaulting a ceiling, basically just removing the sheetrock and keeping the rafters and trusses. This means that I will need to reframe one wall where the attic was common space. It's only 3 feet. What is the best way to plug that space, traditional framing or is there something better, safer, etc?

One more quick comment and then I'll shut up. This is the kind of project you do if you can realistically expect to stay in that house the rest of your lives, or maybe 20 years. Much less than that, and you'll lose money. Possibly a lot of money. The TV shows and websites you're getting "inspiration" from are NOT there to serve you. Their purpose is to move money from your bank account to those of the owners and advertisers. That takes some effort, because most likely their accounts are a lot fuller than yours. (Kind of like what a heat pump does.) To move money from a smaller heap to a bigger one, they manufacture "needs" in your mind. Fertilized by the manure the hosts and writers spread around, these emotional "needs" grow so large that they eventually push out home-ownership reason. Those programs and websites should be used solely for entertainment (and barely that). Otherwise, you'll become yet another of their victims. And that's all I have to say about that.

Attic insulation usually falls into two categories - (most common) leave as unconditioned space, where the attic is vented outside and insulation is installed in the room ceiling below, or create conditioned space, where the attic vents are sealed, the roof deck is insulated and the room ceiling below usually does not have insulation. In your new attic area it sounds like you have conditioned space. If you want to leave it as conditioned space, most contractors will recommend venting it to the rest of the house to maintain a moderate level of air flow through the area. This could be something as simple as an HVAC grill in each end of the area to allow air flow, or you could also install a circulating fan. I have a conditioned attic and I chose to leave it unvented. It is a relatively high volume area (full attic), and during hot weather it seems to stay within about 10 degrees of the temp set in the house. My A/C unit is also located there, so I probably get some residual cooling effect from the duct runs, even though they are insulated. Bruce

This is a structural design issue - it cannot be "guessed at" because the contractor thinks it can be done. It sounds like your contractor is in over their head. Here's what I see and read: - First, research collar ties. They are often mistaken as to what they are utilized for. They are strictly to prevent the rafters from pulling apart at the ridge from uplift/bending. So yes, when they are used properly, metal straps can substitute them. They are used in stick built ridge board framing systems in combination with rafter ties. However . . . - It looks like an old manufactured truss system with mending plates. At least the mending plates would say so, but they seem a bit light and can't tell what is attaching the web chords or the bottom chords. So, the entire gist of trusses is a specific design (meaning exact chord length and placement with mending plate size) for your loads that allow you to use a smaller size of member than if you went with a traditional stick built roof, and being able to span longer distances unsupported. You cannot just convert an existing truss system to a stick built, or vice versa. - If you decided to basically build a new cathedral roof inside your old roof frame, that can be done, and at great difficulty. It is not just the nails that should be sticking through the roof sheathing for asphalt shingles, but the heel space at the top plate. - A handbuilt truss is not going to be adequate, unless an engineer spec'd design is being field checked for compliance with dimensions and fasteners (the typical "glue and screw plywood gussets" is a hillbilly thing best left for sheds, not houses). But, it would be impossible to insert a manufactured scissor truss into the same span, because you only have 2' of spacing to negotiate it to get it above the top plate. And you still have the shingle nails, so the existing top chord needs attached to the new roof diaphragm, so the top chord of the new truss may be approaching a rafter size. - So then you lean towards stick build, where the rafters will be much larger, and whether that can fit into the heel space without being notched or chamfered beyond limits. But without a ridge beam, you need rafter ties, which negates your cathedral ceiling. So then you have to install a ridge beam, where spanning 31' would want a column or two and foundation work to accompany.