Building a new sun-room (converting a covered patio) (so, "new construction" on the openings) and bought some miss-ordered windows from a local window place at a HUGE discount.  When looking at them this weekend in preparation for installing them, they did not have nailing fins for mounting. I have looked on line and these are most often used for replacement but can be used for new construction but I cannot find out a lot on how to physically do this w/o the mounting fins and with no previously finished opening to mount them in.
Anyone walk me through this? 
I learned a lot from my dad, helping him remodel and flip old rent houses when I was in high school. I am reasonably competent but will not call myself a skilled carpenter. 

Double hung triple pane vinyl

You might try the forums over at garden web.  Try the home section.  There are a lot of dudes there who do this kind of stuff.

Good luck!  JD and I would just hire a contractor................

Suzi

I had some new vinyls put in last year. They just slip in between the upright finished window opening and then they screw to the side through the channels. The ones I had put in had a seal all around that filled the gap. Hope this helps.
"gene"