I doubt your home has a true slab foundation; it is likely a spread footing foundation with a non-structural floor. In general, a basement floor can be lowered by underpinning wall sections two to four feet long at a time. Sagging of floors on upper levels is likely normal settlement or inadequate structure. Both these issues are best left to a structural engineer. He who can advise you and create the plans for a contractor to follow to implement the changes you want in a safe manner. As a licenced builder, that's the way I've done it.

In order to figure out the bed line, you need to project forward as to what landscaping could do for the house. Shade is not the only purpose trees have. They can provide "framing" for a structure, making it seem nestled in and sheltered. It makes sense to me that you use a small tree in this way, off of the right front corner. (By "tree," I mean a plant that gets as tall as the one shown in a picture. Not a giant fir. Most likely, it would be made of a large "shrub.") It's going to be impossible to keep the conifer near the corner of the driveway in the shrub form (with branches to the ground) because such limbs and branches will be constantly in the way of using the yard and driveway. It would be best to accept this fact and work on achieving a tree form, which means, don't wait too long before removing bottom branches as the tree grows. A groundcover bed below it now could be circular. Over time, as the tree canopy enlarges, this bed would likely change shade and adapt to the driveway, since it so close. Instead of planting (creating green barricades) in front of the low slung porch, I think it would be better to create a landing across its width that invites a connection and access to the green carpet lawn. If you wanted, you could leave cut-outs in it for planting at the base of the porch columns, for some low color planting. In the process, I would consider enlarging the existing walk some. It seems confined.

Paula, I vote for encouraging all perennials and flower garden people, especially those who arrange them so well in nice big groups instead of polka dots. Maybe you prefer looking out over the big expanse of lawn, but If this were my porch, I would get the height you want by adding one or two of some taller shrubs on the outside of your sweeping sidewalk in order to give a bit more enclosure to the porch. I'm in your zone & I might choose one of the bigger viburnums because of their flowers/berries/& good structure. Or the smaller lilacs? I might even put a low hedge on the outer side of that, creating an enclosure for even more big groups of perennials. Me, I would use the late season fragrant hosta massed inside box, probably, or even dwarf spirea, which is way cheaper & I think looks almost as good in winter. I understand such isn't the current standard in landscape design, which I also like, and it wouldn't be appropriate for someone who doesn't like flowers or gardening, but I'm wholeheartedly in favor of those who have some garden personality flashing it ! Sam

Thank you for your feedback. The small house and shop sit next to seven acres of fields so we are unsure how to anchor house and yet balance house versus fields. But we were leaning toward softer, smaller plantings of pinks & blues. Even mophead hydrangea feel too big.