I needed to reduce the sun's glare and heat in our garden summerhouse and the blinds I installed last year didn't do the job. After further research, I found Active Window Films have the solution as the windows are double glazed and you can't fit film on the inside, only on the outer face. I ordered a sample and put that on as a test and wow, the glare was gone but it was too small to verify heat reduction. Nevertheless, I ordered the film and now, om;y time will tell but I am sure it is the fix I needed. Very helpful customer service too with questions being answered very quickly.