Conifer is dying?

Conifer has been going brown from the bottom for about a month now and the needles are dropping off-any ideas or solutions?.
I have looked on the web but cant decipher if its a pest thing-root disease etc.
It has been well watered.
Thanks in advance

 

I don't think that is going to recover, even if it stays alive it will always look bad as I doubt the brown parts will ever green up.
Just a wild guess, but there is a specific aphid that attack spruce and fir trees, if you don't catch it in time it causes similar to what you have there. But the damage would have been done last year.
Another suggestion, does it get waterlogged in the winter ?
Does it get run off from the shed, maybe.

 

Another question, how long has it been there?