Cut it back

Cut the parts that have broken out of the espalier shape out and you are back where you need to be. Obviously it's a type of tree that tolerates heavy pruning, that is how it is possible to use it for espalier in the first place. It won't love having the now most vigorous parts removed but that won't kill it either.

I am more concerned about the bareness of the bottom half of the original structure, something is not right in the situation there for this to happen. You don't have deer coming and repeatedly browsing this part of the specimen do you?

Thank you all for your recommendations! I will prune out the dead wood and where it's beyond the shape I want it to be. I will google festooning. And YES, we have regular deer in our yard that eat everything, so maybe they are the cause of the dead lower branches. I hadn't thought of that!

Espaliers work best where they get lots of light so that is the first question . Right now it looks like it is stretching to get light.

The two long branches are that way simply because they have not been kept cut back. If the two lowest tiers are completely dead then the espalier shape has in fact been pretty much lost as this point because that leaves only the third, uppermost tier of trained branches. And since the roof overhang looks to be close by, producing a visual crowding - if not also a physical one - the tree may not generate an appealing effect if trained from this point to consist mostly of growth above deer- and facia height. Because the specimen is already trained as an espalier the impression created is that it needs to be dug up and placed hard against the wall, pruned and trained to stay within the confines of it. So it might be best to discard it and start over with another one, maybe in a different spot. One that is protected by deer fencing.

In the dead of winter, you could try cutting it off between waist and head high and, hopefully, it will fork and grow thicker at the lower height.

While it is dormant and/or cut, you might consider moving it to a more open space and let it "do its thing" rather than trying to force it to grow against a wall or in an unnatural shape.

The likely reason the tree is growing tall and dropping bottom limbs is that it is reaching for full sunlight.

I've just looked again at the pictures and Embothrium is right. The tree is too far from the wall to espalier successfully. Unless you build the necessary frame out in the bed which will look weird.

Thanks for the suggestions!....The pear tree is facing south but with the house on its east and large spruces on its west; otherwise it gets full southern and southwestern exposure. I always wondered if the brick alcove stressed the tree when it's hot or sunny out.

It seems the best way to treat the tree is pretty drastic. I am afraid to dig it out and replant in a more appropriate spot (although that would be neat and I'm still thinking about it!) and cutting it severely would be a great experiment for me. However, I am thinking of trying to festoon the tree...it may bring the scale back in line with the house and would be of visual interest if I can pull it off. With the issue of the browsing deer, they usually prefer other vegetation on our property so maybe they won't get around to the pear tree. I will keep an eye on it in the meantime, and I'll spread a lot of milorganite in the area.

I know its a tall feat and I'll probably spend all kinds of time trying to create something and then get frustrated and mad, but I'll see how it goes. Those dead branches aren't coming back, are they? So I can completely eliminate them?