I'd put in a fence (that's what we do in CA!) and trees in front of it. You'll need to include some climate info for tree recommendations, though, as well as how much space you actually have.

I've never understood this privacy obsession. I guess if his building is going to wreck your naked hot tub parties....

Fence and trees seems no brainer. I’m not sure why this is motivating you though...your backyard appears to be a pile of dirt. I’m not sure my first investment out there would be fencing and trees to hide it from others...

I would need to see more of your plot and how the new house even relates to it. I agree with the abnormal worry about privacy, you really will never have it in a sub division no matter what you do. What is it you do in your yard that is so private ,should have bought acreage if that was the first need. I guess I would need to know what spaces from his house will even look into your yard. I would like to see your space and what is all the stuff blacked out in the photo.

Put up a nice wood fence around the yard on the property line. Then on your side of the fence, put up a mix of trees and shrubs. Don't make a straight line of all one thing. Not only is it unnatural, but if one types dies, you haven't lost everything. You don't have to do everything at once. Add different plants as they grow. Do the fence now. When the house gets a little more along, sit outside where you normally would be and get an idea of what you need screened.

If I could of bought the farm, I sure would have. That wasn't in the budget. And although, I like my neighbors, I still like a little less view of them, especially in the backyard.

It would be foolish to sod the yard, then try to do a fence and plants. Fence first. Plant beds second. Yard last.

Also, if you are going to want more deck or patio, now is the time.

Can you post a picture where we can actually see the yard?

I grew up in a two parent household with 8 siblings. our house was 1300 sq ft on a 1/4 acre lot. Dad had to finish the attic and basement to fit us all. I love my family but I totally understand your desire for a little privacy. I relish mine now and I can't go back. Do white pines do well where you are? That's what we're surrounded by and they make a beautiful privacy fence year round. they grow pretty fast too.

A privacy fence that looks good on both sides plus a few trees will give all the privacy you should need. The closer the tree is to the area you want to protect, the shorter it needs to be.

I would look for a native hardwood and a couple of ornamental ones. I have Sargent crabapple, it is gorgeous in spring and about twenty feet tall.

Does it have to look good on two sides? Depends on where it's placed I suppose, and local laws and customs.

If fences are common in your area, it might be worth asking the new neighbor if she'd like to pay for half of a mutual fence.

If someone doesn't "get" the desire or need for privacy in one's own yard, then there is probably nothing anyone can say that will make it clear.

There is nothing more desirable in my garden and home than my privacy. No, I'm not naked in my garden, but if I wanted to be, that's the level of privacy I require. I live on 1/2 acre, with houses on two sides and another's garden on the 3rd side, but no one can see into my yard, because I've planted extensively to make it a private sanctuary.

Besides my privacy, I don't want to be forced to see someone else's house - not everyone makes good design/color/upkeep choices and I'd prefer to not have to find out what theirs might be.

For the OP, there are many, many threads here with your exact question, so if you do a search at the top of the page, you might get more ideas and visuals of options.