The poem plays on the fairy tale of Jack and the Beanstalk, then tells us right away that this version is different: there are no magic beans. Instead, a house jack, the tool used to lift a sagging building, becomes the thing that grows. The pun on "man-jack" (every ordinary person) and "acme-threaded" (the screw threads of a jack, with "acme" also hinting at a peak) turns a mechanical object into a beanstalk.
The second half shifts to a quieter, domestic scene. A dog under the porch sniffs at sunlight, which seems to gather as the house rises. The old building "climbs groaning into the sky," and the groan sounds both like creaking timber and like effort.
The speaker doesn't state a feeling outright, but the tone feels amused and quietly wondering. The mood is playful and a little magical, with a sense that something heavy and worn can still be lifted. The title's "ode" suggests the speaker admires the humble tool that makes it possible.