I think you would do much better using a nicer looking modular block and 6" high. Since it is only 5' wide, I would suggest capping it with a tread of saw cut stone such as bluestone or limestone attached with an adhesive so that it takes the freeze/thaw cycle.

Roman Pisa with bluestone on top looks pretty good in my opinion. It is not as cheap as using all concrete products from Home Depot, but you could still just as easily build it yourself with nicer results.

And then ... why have steps at all? Although it will be a little more expensive, a charming and evocative entry can be garnered by constructing an inclined pathway with pavers (perhaps curved) that ends at the same level as your door threshold.

Steps are problematic and generally a PITA.

IronBelly

The problem comes with normal box framing, building code, and water.

There is typically 12" of wood construction beneath the interior level of floor and building code requires an 8" separation between the wood and the grade around the house.. If you add a ramp to the door 4' above grade, it will be a long ramp with a landing on the top (building code unless it is a slider. It will require more railing than the steps.

It would either be a much larger monstrosity than the steps unless you want to have soil make up the shoulders of the ramp. In that case, you either have to bury the side of the house to create those shoulders, so it will not easily work on a typical box frame house. Being that the house is 4' off the ground, I think it is safe to assume it is not slab construction.

It is the old ying & yang. All of the above it true. However, it can be done, albeit not realistic (or perhaps affordable) for all situations. On the other hand, when this approach is taken (pun intended), the results can be very pleasant.

I offer this concept to stimulate the thought process -- particularly for those either contemplating new construction or major remodeling. It is a lot easier to implement this idea when taken into consideration during the initial design process. A resultant four foot drop out the back door shows that this clearly was not the case.

Although not always possible, eliminating steps can be done and should be done more often. This usually only happens via a novel concept called thoughtful design.

IronBelly

Unfortunately, thoughtful design has to start with an architect that understands grading and drainage and won't stick you with many obstacles to overcome.

I think it is a safe bet that anyone contemplating a DIY project with that product in this situation has a limited budget. A budget that is not likely to overcome those obstacles that would allow a thoughtful ramp.

You really have to know that the construction of a ramp going up 4' is going to create a number of new problems. They include aesthetic problems as well. Until the need for this type of access outweighs those problems it is unlikely to happen.

I've done several HP rail-less walks (won't call it a ramp until it is >5% when it is an ADA access) into buildings. They are very difficult. The concept is easy, but once you start working the perifery, the issues start to surface. Drainage is the big one followed by fill against places it should not be, and then by length. There is a reason why most ADA ramps are big, ugly, and in your face and it is not because someone did not care that it looked that way.

Check on the building code. Around here a set of steps 4 ft high requires a railing, or the design has to be wrap-around steps, so you can't fall off them.

If you have the money, and space, and it fits with your design, natural stone steps look very nice.