You need more than a lintel, you need a beam. It can be a flush rim joist beam, then the two joists hangered off of that. You have some electrical in the way. Of course if started from scratch a CMU wall would be grouted solid next to openings and where acting as bearing posts, and if this was a basement wall below grade now exposed with a walk-up door then the frost footing at the door is non-existent.

Thought that might be the case, seemed like a lintel required block above. In this case, should I be looking to make a header essentially out of 2 x 8's glued and screwed together? The door frame is 2x6's, would act like jack studs. Not sure how they're secured to the block, but could add some concrete anchors to them.

A correctly sized steel lintel would work. But at this point, some gradual jacking of the floor beam and attached sill plate to level could be a good start. But I defer all specs to a qualified engineer.

Semantics, a lintel would support an opening where the CMU continues above and you are just supporting that material. No reason for steel, here the CMU stops at the plate so you need a rim beam to support the floor diaphragm, upper wall, and roof. The beam can sit on top of the existing plate but extend across enough to bear onto the CMU, that will allow the 2x6 jacks to be reduced to 1x as needed for extra width and you can then slip in a prehung exterior door.

Semantics

Got me!

Lintel vs. beam.

Still, need jack support on the three floor joists while the blocks on either side of the opening are knocked free and a properly sized wood (or steel) beam is inserted.

if this was a basement wall below grade now exposed with a walk-up door then the frost footing at the door is non-existent.

If this is a cold climate, at the least, excavate two-four feet down and insulate the wall with exterior foam board.

Simple job. You should have a 2x8 rim joist flush with the existing sill. Cut a 2x4 about an inch bigger than the floor to joist distance. Whack it with a sledgehammer until you raise the joist about a 1/4". Cut the nails that connect joist to the sill and then slip on a joist hanger and screw it into the existing rim board. Remove 2x4. That should cost you about $.89 if you have some scrap lumber laying around.

If this is a cold climate wear gloves...

Not to overthink this, it's an easy fix... the door opening is not that big it looks like a 24" door with 1 1/2" frame most likely full width of the block and they can easily support the header which only supporting 1-floor joist.

Jack up that one sagging joist to make it level, cut the sill plate out and slip in a double header in. If the door will be changed down the road and it will have a new standard frame... when the door is out you can fix it the right way. The house is an older home, foundation is cinder block and plate is on top of hollow top course with only grouted blocks which have anchor bolts (see that in many older homes) and even if its a semi-solid top course it can be easily cut on each side to make a seat for a header if needed.

Here is a cross cut section view

The door is 30", with 1 1/2" frame on the sides. Our house is on a big hill, so the front of the house is buried, the back is completely exposed (bottom of the concrete block is level with the ground). Our garage is cut into the basement wall. We live in upstate NY, so its cold...was planning on adding foam board to the interior shortly.

Beam vs. lintel vs. joist hangers. I figured that joist hangers would help but wouldn't be a solution on their own. I was thinking I'd need something like a load bearing header (that was the terminology I was thinking of originally). If I was to go that direction I would build a temporary support to carry the two joists. Cut into the block a few inches (like 6?) on each side with an angle grinder. Insert a beam (2 or 3 2x8x46" boards glued and nailed) to carry the load to to the ground. Not sure if that's overkill. And was worried about the possibility of cracking the blocks.

3onthetree - when you say "The beam can sit on top of the existing plate but extend across enough to bear onto the CMU" how would I put the beam on the plate without cutting back the joists?

Yes, you would have to cut back the 2 joists (the right side one would interfere with the bearing distance on top of the CMU. I disagree with a couple of the comments.

First, you want a modern weathersealed door. The door looks mortised right into the 2x4 frame. So to remove the 30" door slab and leave the jack studs to support a header would mean you need a 28" prehung exterior door. Good luck finding or living with that. So the jack stud method is out.

Second, I estimate 4.75" height between the existing door head and bottom side of sill plate. So even cutting the sill plate out, you can only fit a 6.25" header between the top of door (assuming top of existing door frame head is at 82.5") and bottom of joist even if you cut out the CMU for pockets. Don't know how many floors or the loads this would support, but a 6.25" header would appear to be inadequate.

So, sistering more 2x8's in between the sill plate and sheathing, against the rim board, would be the best situation. Floor joists cannot hang off of a single rim board, so you need minimum (2), I would make it (3) if that meets the same width of the sill plate (can't tell if it's 2x4, 6, or 8). However, I understand that would be difficult to slip these ~42" long sisters by the joists, above the sill, and interfere with the cable there.

To make an "easier" install then, you could cut the CMU for pockets at 82.5" AFF, remove a portion of sill plate, notch the (2) existing joists for a ledger bearing, and slide a (2) 2x12 header flush with the inside CMU face.

Use that chart above to see if your single 2x8 header is adequate. If you're close, bang on that joist hanger and start looking at new doors.

If not, take the door out and cut back the joist 1 5/8" and slip another 2x8 in there resting on the existing sill. Nail it up, bang the joist hanger in , then have a beer....

Lost count how many repairs like this I did and still doing.

I found something to what you got there, just a bit more work involved, rotted rim joist and sill plate, doubling up rim-joist over the much larger opening for a crawl space, etc

This way you get an idea of what you dealing with if you want to address your issue from the other side.

@ksc36, if you make a recommendation, read and re-read the verbage and look at the pic. Anyone can redneck a wrong solution but you're missing a bunch of info.

I agree info is missing. Installing a joist hanger is framing 101.

This is just bizarre, "To make an "easier" install then, you could cut the CMU for pockets at 82.5" AFF, remove a portion of sill plate, notch the (2) existing joists for a ledger bearing, and slide a (2) 2x12 header flush with the inside CMU face." Nothing easy about that "redneck" solution.

As is this, and shows a basic lack of knowledge in residential framing.

"Floor joists cannot hang off of a single rim board"

The opening is 33", look at the chart above. If you pretend the 2x8 joists are rated for the existing span, the overall span should be less than 24'. If it's a one story house then a single 2x8 "header" will span 39". If it's a 2 story house, 2x2x8 will span over 39". If you are worried about the right side not having enough bearing for the 2nd 2x8, simply hang that single 2x8 off the existing joist with another hanger. So now we are up to $4.69 for materials and an hours work including cleanup.

As always, not enough info to come up with a prescriptive solution.

Let's also not forget that the existing rim joists already there picking up a significant load amount. This is a very simple and quick fix.

That said, that header only needs 1 1/2" of bearing which is already there (2x on each side)... If you making a pocket in masonry for a wood header you will need 3" min bearing support.

The info missing is in your reading of this situation, but is there to see. Glossing over the door slab is 30", so removing it would make the new rough opening 30". Glossing over the existing 2x4 jambs now needing to be removed means there are no jacks to support a header. Glossing over the space available for a header below the sill plate. Glossing over that no, you cannot hang an unsupported floor joist into a single perpendicular member (the rim joist in this instance) or hang a beam from a single floor joist next to it making that joist a girder. I could even get into how a rim joist keeps the floor joists from lateral movement, not to support upper loads individually. It seems you're a little light on framing.

What I did do is revise my advice after the OP questioned how to slip a beam in there and cut the joists. So I gave another solution with OP is set on cutting out the CMU, and put "easier" in quotes because it's obviously not easy. But like I said, reread and understand the situation.

Here's some "light reading" for you. There's pictures if you don't understand...

R602.7.2 Rim Board Headers

Rim board header size, material and span shall be in accordance with Table R602.7(1). Rim board headers shall be constructed in accordance with Figure R602.7.2 and shall be supported at each end by full-height studs. The number of full-height studs at each end shall be not less than the number of studs displaced by half of the header span based on the maximum stud spacing in accordance with Table R602.3(5). Rim board headers supporting concentrated loads shall be designed in accordance with accepted engineering practice.

In my world the door and jambs are already in the trash. Now I have a 33" opening and can fit an easily sourced 2/6, glossy, prehung door in there. The space below the "rim board "header" can be filled with scrap as needed...

Thank you guys for all of the information. CME pockets/load bearing header was something I saw while I was researching how to fix this...didn't take exact measurements in the basement, but in reading I lost track of how much room above the door I had to work with. 4 inches or so definitely isn't enough, thought I had more space. Cutting into the foundation is definitely not "easier".

I still have one question (this is the dumb one). I know that a single rim board isn't enough to carry the load, so I'll need to sister at minimum one more (I'll do two or three because I have a floor and a half above). I know how to install a joist hanger, that's not a problem. But, how do I get the rim board header into the space (behind the floor joists and in front of the rim board)? I can't slide the 42" boards into the space if I go between the joists diagonally. Can't go above (floor). I assume I have to go in below, in between the joists and the sill plate, but is there enough room if I jack up the joists an inch above the sill plate? Was thinking I'd cut the sill plate between the door (since its not carrying the load and there's no blocks there), add on two or three boards (from below) till its flush with the wall, and then hang the joists off that. But, the pictures all show the sill plate intact for the rim board header.

Use this table to see what you actually need. Table R602.7(1). What's the width of the house and what are you calling a "half" story? What snow load does your town require? The single 2x8 might still be adequate.