How far away is the farthest house from the main house with the fiber connection?
I'm not an expert here, but this is how it seems to me ...
An outdoor point-to-point wireless bridge is supposed to be better, but depending on how far the houses are from the access point house, just running Ethernet cable (e.g., in a trench, with or without conduit) from one building to the other would probably be cheaper for distances less than 100m between buildings (and a cable will always be more performant / reliable).
You'd need a separate pair of bridge units for each secondary house you're connecting to the main house, with a line-of-sight view between each pair of bridge units. Whether you use bridges of run Ethernet cable between the buildings you'd need additional Wi-Fi routers or wireless access points in each secondary building too (connected either to the bridge of the Ethernet cable) to enable Wi-Fi connectivity within the houses (or just network switches to directly plug any computers with additional shorter segments of Ethernet patch cables if no Wi-Fi for mobile devices is necessary in any given house).
some examples
in this bridge example, I assume the short bits of Ethernet cables that are outside are outdoor-rated ethernet cables (e.g., with UV-shielding jackets)
[media=https://www.youtube.com/watch?v=_WPS3tTW7X8]
another bridge example
[media=https://www.youtube.com/watch?v=aSL-z6iR7m4]
running Ethernet between buildings example
[media=https://www.youtube.com/watch?v=tFcMs5_Y6C8]
another Ethernet example
[media=https://www.youtube.com/watch?v=8cleqSVWWjE]
