If you have a large garden or a smallholding then an outside toilet will eliminate muddy footprints in the house. It will keep working all year too as waterless toilets cannot freeze in winter. Perhaps you have a remote building like a beach hut or woodland cabin that needs sanitation.
Some examples of NatSol toilets on private sites:-
Beach Hut Compact Toilet
Description:A private beach hut. The cubicle doubles as a shower cubicle.
A composting toilet for a smallholding in Wales
Building/Toilet Type:Standard Timber/Full Access
Description:Sneaked into a hedge line between trees it looks just like a garden shed and will, no doubt, be used as one from time to time.
"Our composting toilet is absolutely fantastic and now doubles up as my garden shed! The installation was well co-ordinated and professional and the toilet was ready to use immediately. Thanks for making our dreams a reality." SR