Preliminary investigation

So far, this wekend I've managed to partially gut the bathroom in an attempt to indentify some of the problems within the wall assemblies.
I've found that the windows have been installed with no protective membranes (blue skin), which doesn't surprise me, considering that there s a noticeable draft comming from multiple windows within the building.They've also been installed in a fashion that doesn't allow water to be channeled to the exterior wall face, allowing the moisture to sit in the wall assembly causing mold and wood rot. Most likely I'll have to replace the windows with some more energy efficient windows, and properly seal their instalation.
Also, the exterior walls are only 2"x4" stud walls, with one layer of what appears to be R12 or R16 batt. insulation. Now, because the funds to rebuild the whole house aren't available, I'll have to improvise and find an insulation that will fit in the 2"x4" wall space and give the appropriate "R" value.
I've already pulled off some of the siding and found that the exterior of the envelope isn't too bad, just not too aesthetically appeasing.
I have some pictures of these descriptions but have accidentally misplaced my camera, but they will be posted soon.
Feel free to comment, any constructive critism is more than welcome.

Welcome

Welcome to all who are willing to make a constuctive comment and help determine the best way to bring my house up to code (Main focus is insulation). I look forward to hearing what ideas you all have.