This is intended behaviour both in eTool and the BRE submission sheet. You can only conduct a comparison to a benchmark if you model the project using the BRE IMPACT V5 dataset within eTool (i.e. when setting the project up, see screenshot below). As your model is using the eTool default dataset you can’t choose a benchmark model when downloading the BRE reports.
The catch 22 here is that BREEAM only allows you to claim the comparison to a benchmark credit if you are using their dataset, but also only allow you to claim the services credits if you use an alternative dataset. To claim both does mean some of the modelling needs to be conducted twice. Unfortunately you can’t swap between the Default data set and the BRE IMPACT dataset (essentially because there isn’t a neat 1:1 relationship between materials, disposal processes, transport processes and energy processes in the respective libraries). We evaluated whether we could establish a mapping system to allow users to migrate models between the two datasets and identified significant complexity in delivering this in a user friendly and accurate manner. We also understand that achieving the benchmark credits is very difficult (based on feedback from many users) and most projects were no longer targeting those credits. As a result we didn’t proceed.
If the benchmarking credit is something you definitely want to target let us know and we’ll give you some pointers on how you can relatively quickly migrate your model. Note that you will need to maintain the model in both datasets if you want to also claim the services credits.
Apologies for the confusion, the credit is pretty complicated in terms of what datasets / tool can be used for each part of the credit.