Assess the structural integrity of the double-wide mobile home. Look for weak flooring, leaks in the roof, any past fire damage or wiring issues. Check under beds and built-in sofas, for example, to determine how sound all sections of subflooring are. Examine the mobile home underneath the crawlspace, too.
Build a house shape of framework over the entire structure. Create a sloping roof to replace the flat or rounded shape of the mobile home roof. Think of constructing wooden framing to fit over the old double-wide like a tight box. Use 2-by-6-inch boards and plan to add 6 inches of roll fiberglass insulation before installing new exterior siding.
Plan the exterior siding material and foundation improvements. Install faux stone exterior siding in the crawlspace area, as one choice. Plan to add exterior house siding or half logs, as possible choices, to cover the entire exterior for a cabin look. Construct framing to support tongue-and-groove boards all over the structure as another possibility. Design and build the exterior to look like a mountain or lakeside cabin that was stick-built on the lot.
Keep the same window size openings, if possible. Buy or find energy-efficient windows to replace the old ones. Add sturdier wooden window framing as you construct the new exterior covering over the metal or wood structure. Avoid changing the size of the windows to make the remodel easier. Install one or two sliding glass door systems to open the new "cabin" to a deck. Create the space for sliding doors, if possible, by taking out a double window, rather than trying to cut a new opening.
Use bead board paneling, drywall and rustic paneling bought at close-out sales to finish up inside rooms. Paint over old, dark paneling with white semi-gloss paint, as another option. Find rustic tables and faux leather sofas and chairs at close-out sales. Add artwork and rugs to give the new home a cabin feeling.