Build a wall around them and cover T1-11 or sheathing and siding to match the house.

I’m trying to make this spot an opportunity for storarage of outdoor items after you build the wall @millworkman suggests. What’s the height of that space on that side under deck? That is also the front of the house, right?

KW PNW Z8 this is the front of our home where there’s a bedroom window looking out to our waterfront. I like the idea of storage and the height is quite short, 5’ at the most.

Storage space would be a great idea after building something around it

So - storage….needs a roof like a shed roof shape tilted towards gravel so water coming through from spaces between deck planks can run off. Stairs need to be demossed & cleaned. Needs a big door for access - probably best on side the stairs point to & with door opening towards the house for full light & access. Need to figure out how to build out steps to make shelves at top. Maybe the ’shed’ wall on open side is longer than staircase so there’s a flat surface at bottom on ’sidewalk’ to set things on. Storage space could extend out to outlet in wall between stairs & window. Is that a light above the window or a shade? Or a pipe / conduit?

Make the framing changes necessary to reopen the stairs please.

Well, now there’s a good thought from Joseph! Is it possible to reopen the stairs & would 2 ways to get to top deck be a problem? They ’arrive’ pretty close together but they start pretty far apart.

This ours an earlier photo I find on a proper for sale listing. Looks like the concrete stairs went up into the home.

“ Found on a prior “ darn spell check

If turning them into useable stairs isn't what you can or want to do, I'd clean them, then fix it so it's a smooth slope that sheds water better. Paint with anti-mold paint.