How do I shorten a Monkey Puzzle tree?

Chop it off at the base, and allow it to collapse to the ground.
Cover with taupaulin.
Cannot see it now, eh?

Methinks that Burgundy is being funny. In a similar vein, you could dig a 30 foot deep hole and drop the tree into it.
Being more serious, Tiglig, I don't see that there is anything that you can do with the tree apart from removing it. Shame, but we sometimes have to take drastic action.

So far as I know, and ignoring the daffy 'B' ducks, you can't prune a Monkey Puzzle tree. They naturally grown to over 30 metres and any attempt to prune just leaves them looking odd. Obviously you can just chop back the branches near the house but, if the tree is that near to the house, what are the roots doing?

Might be better to have it removed now that its outgrown the space you have - these trees are often "temporary" visitors to the garden because they do get so large - you've obviously had the pleasure of this one for a long time, but its probably time to call it a day, I'm afraid.

What a shame for you to have to be thinking of this, but - i have to agree with Mg and Bamboo, if you can't live with it you'll have to remove it :(

They're my favourite tree.

My feeble attempt at wit seems to have had it's ground covered by others. Sure, in other climes they can be induced to sprout some legs from a young branch at over 1 mtr in length, but alas, in Uk, temperatures are just not high enough.
Hey, give it a go next April; you never know.

searious now boy's, move the house, I think that Moon grower will agree with me she seems to love trees