Many churches have installed glass screens with the aim of creating a draught-proof entrance while allowing a clear view into the interior.
These require careful handling at design stage to achieve a satisfactory result.
Whilst there are some drawbacks, these can be dealt with if they are clearly identified in the early stages, keeping in mind the need to balance the air flow and heat loss/gains at all times.
This guidance note will give you more information and provide some examples of effective glass screens in other churches.
The Diocese of London has published a guidance note on installing glass doors and draught lobbies which can be found here