Having the porch at least 6', if not 8' deep would work best.
The upstairs exterior walls are directly above the downstairs exterior wall.
This home pictured hereinafter has the full length front porch beneath the steep part of the slope of a barn style roof and can give you a visual of what I mean. Within the upstairs barn style roof (part you could you'd finish last - w/the plumbing roughed in ahead of time, of course) could be two bedrooms and a bath and a half between them - creating a three bedroom family home, providing room for guests and protecting the resale value of your new house while giving you plenty of room downstairs for a couple starting out or empty nesters. Then decide on an interior floor plan, with existing plumbing and electrical access in mind and what rooms you want where with what windows you want where - a plan that will give you one master bedroom suite downstairs (and plenty of closet space and a utility room for your washer/dryer ironing board) - a plan that will give you an open floor plan to make a small home feel larger - including in your floor plan access to a stairwell (that could be built in the center of the back just outside the existing exterior wall protruding into what could otherwise be a full length back porch (and steps with a landing so the steps turn at a 180 degree back toward the upstairs) - all beneath a barn style roof. Start by measuring the entire width and length of the home so you know the space you have.
Not a pro but, since you need a new roof anyway, use that as one of several `good reason to change the style of the roof. Thanks for all suggestions on dressing up vinyl siding, keep em coming. It is not a question of should I stain or should I side that decision has been made. It involves much more than appearance/color and we are just done. Many people love the look of cedar until they have to maintain it. We love the look of cedar but can no longer continue with this high maintenance ourselves and buyers love maintenance free. Several boards are warped and inspite of repairing all critter damage last year the birds and squirrels have returned. My DH would have prefered being on a golf course instead of a big ladder every summer. Honestly had we known the cost was so reasonable we would have replaced it 20 years ago.
We looked into having it professionally power washed & stained with a solid base stain and since it was so expensive we also checked out the low cost, maintenance free lifetime warranty vinyl siding option which promises to eliminate the critter problems. It is very high maintenance as it is beloved by woodpeckers, birds, and squirrels. The cedar has been repaired and replaced on a regular basis over the last 30 years and is now 3 colors. Jennifer thanks for the heads up on painting garage doors with lifetime coatings I will give that more investigation to see how it affects future maintenance. Maureen just a few touches of cream really set it off thanks for the visual.
I know how I'd install a door in a open wall before installing siding but tying into the existing stuff without pulling it back. Does anyone have any tips or thoughts - or videos addressing this particular aspect (there are plenty good videos about the door hanging itself, which I'm comfortable with). except for the threshold being nearly on-grade and snow which I can sort out. The door is fairly well sheltered by deep eaves overhanging and only sees water in very windy storms, so I'm ok if it's not the pinnacle of perfect water protection for the next few years until I redo the whole siding. It may be somewhat brittle to rework but there's no evidence of that (no breakage anywhere). It's dated and a little chalky but it was installed very well and is in fine shape and I'm planning to get another 5-10 years out of it. It's old 80's vinyl with aluminum flashing and vinyl j-channel.
I need to replace an exterior door but I'm not sure how to handle the exterior siding and trim without making a big project out of it.