Hedges to reach the top left windows for privacy on that floor? Don't know your house's orientation but wouldn't window treatments be easier and allow better light control? During daytime, we usually can't see into windows. It's only when it's dark out and there's light inside the house. You might want to test how much visibility your interior gets from the street before planting something that will obscure your house that much. Also, not sure what you mean about increasing the window size horizontally.

I honestly can't see how widening the windows would be an option unless you want to revamp the whole exterior. What is you reason for wnating to make the windows wider? if you want help with the hedge issue you need to post a pic from further back to see the whole space but usually hedges for privacy need to be very high and often not that attractive, Privacy IMO is more important for the back yard where you usually would have seating and also where you would normally do entertaining I think what would be nice here is a walkway from the street to the front door , removing that tree on the left between the lower windows and add some nice low plantings

Sorry I meant vertically !

The house sits on a hill, there is about 5 ft retaining wall so all you would see are cars and people's heads walking by. Hedges would just make it less viewable from the sidewalk.

They are bedroom windows. We have to replace them soon as they are single pane.

You could change them, but they are part of the mid century aesthetic of the house. I would remove the poor stunted bush under the overhang... I love the idea of a dense hedge by the street- I have done that in a couple houses and it really makes the house feel more private.

Changing the windows would be expensive and give you little for the money. They might damage the proportions of your house.

For privacy on the second floor, you want trees, because a hedge has to be quite tall. Pick one or two trees that will grow tall enough and plant in the line of sight. Think about how you will change your garden beds to accommodate the new tree. Make sure it wwill grow tall enough, that pink redbud or crabapple clearly isn't tall enough.

Thank you for your comments! yes that "tree" is a jasmine vine that I hope to move soon as it makes the walkway impossible to use. I definitely want to stick with the mid century vibe, so it sounds like better landscaping might be the answer.