Some insulation value can be derived by covering with thatching. Many want to skip some of the Monolithic process and still derive the same benefits. We have not figured out how to do it. We can build an EcoShell, spray the outside with urethane foam insulation, then coat over the urethane. In general it is the same structure as the Monolithic Dome but not really.
Construction is more difficult.
It will never be as well controlled, well a constructed building, and always costs at least as much money if not more. If the cost for a new home is too high, make it smaller, but don't sacrifice having a permanent residence. Having said this, let me explain that there are people building EcoShells, covering them with straw bales and then building another EcoShell over the outside of that. This can be done. It is doubtful that it will save money, and there are problems with the details for the doors and the windows.