Let's look at the language of the first stanza; I will put stressed syllables in a bold font and use the "|" symbol to separate metrical feet:

I mean | to build | a hall | a non
And shape | two tur | rets there
And a | broad new | elled stair
And a | cool well | for cry | stal wa | ter
Yes; I | will build | a hall | a non
Plant ro | ses love | shall feed | u pon
And ap | ple trees | and pear

The first line has four feet, each consisting of one unaccented syllable followed by one accented syllable: these are called iambs. This meter is called iambic tetrameter. The second line, however, only has three iambs. This is called iambic trimeter. The third line has three iambs as well, but then the fourth line not only has four iambs (like the first line), but it also has an extrametrical syllable at the end "("ter"). The fifth line has four iambs; the sixth line has four as well, and the the final and seventh line of the stanza has only three. We would go with the meter used most frequently in the poem, so we can call this a work written in iambic tetrameter: four feet per (most) lines and the foot is an iamb.

The rhyme scheme is as follows: abbcaac. This means that lines 1, 5, and 6 have end rhyme. Lines 2 and 3 also have end rhyme, and so do lines 4 and 7.