This really isn't much about the planning, as we only see the final design, but it's notable that it's a team work and that the binder with the plan is there during the building phase.
http://www.zababov.cz/vs/Moduly/H0_FreeMo/NEOFreeMo.htm
More from the modular club here: http://www.zababov.cz/Us_index.htm
http://www.zababov.cz/vs/Moduly/H0_FreeMo/NEOFreeMo.htm
More from the modular club here: http://www.zababov.cz/Us_index.htm