Maybe have the admins build a player base at the start which everyone uses and ban building everywhere else, these could work to a theme (a monastry, hotel, prison, cruise ship) each wipe. Every player gets allocated a 1x2 room with a little window, a bed and some space for storage, everything else like furnaces, work benches etc are communal. You'd add a little area for heli and car parking.
You might suffer a wee bit of stutter in the commune, but the rest of the map would be free to roam without issue and without some of the eyesores people build. Also, it would help to preotect the flora and forna. The amount of times I've seen people deforest an area to build an ugly base and then just leave it to decay is shocking.
This gets rid of all the ghastly compost farms, massive wind turbine carbuncles and all the other issues affecting our wonderful islands.