My house already had some sort of “let light in but people can’t see in” type curtains when I moved in which I immediately added two layers of the thickest, fattest blackout curtains to. The temperature during the summer immediately dropped a huge amount (plus I can watch tv when the sun is out, my actual reason for it) and I can’t hear street noises besides those dipshit kids with the loud cars (or their smalldick dads with the Harley and/or lifted truck- all of which are explicitly illegal (noise ordinances) and yet……) and maybe if someone is guffawing directly in front of my house, which basically never happens. Pretty nice. Didn’t cost much with either. I also out similar curtains up in my bedrooms for climate control and noise. I might need to add another layer to those though!