Since you're a founder, maybe you can shift some of your focus-heavy work to night time. A lot of your noise sources shouldn't be an issue then.

If moving is ever an option, you might consider a house with a furnished basement. You can setup your main office there, or just have a second work area for when you need the extra quiet. It's also possible to add some treatments to a room to sound-proof it to some degree, up to the extent you might find in a recording or studio booth, say in a radio station.