Don't build a lighthouse base on three foundations, there is a better way to do it.
The construction of a more spacious house will start from the same stones, the only difference is that you need to walk forward a little and jumping under the water to find a place for the first foundation, trying to place it as close as possible to the stones on which the lighthouse stands.
Next, we allocate the required number of foundations for the main base and, if desired, extend the chain of foundations around the lighthouse, so you can mark out the remote elements of the base both for capturing territory and, for example, for organizing traps or constructing platforms for installing turrets or other defensive structures.
This method will allow you to expand the base, diverting new foundation blocks away from the lighthouse, plan and build buffers, and generally provide yourself with the space you need, and no one has canceled the tower to control the processor either.