If you are looking for Stovefitter’s FREE twin wall design service: twin wall design service
Examples of typical twin wall installations are shown below:
The scenario below is a difficult scenario due to Building Regs stating a recommendation that flue is a minimum 4.5m above the stove (as it is a recommendation they “may” allow 4m) and hence there will be a lot of free standing flue “swaying around in big winds”. Two metres is max free standing recommended by manufacturers. See this page for an installation where a supporting bracket has been created. You may wish to consider Scenario 5.