I have to ask the question on why you want the utility blocked in as this is sometimes irreversable.
We are manufacturing some fixed blinds over balconies, patios, arches and gardens, etc. with a high tech commercial grade fabric from Australia. What these do is to keep 90% of the sun out whilst at the same time letting the airflow through keeping the space cool. Because they are fixed romans they will not blow around in the wind but can be pulled up and down to suit. your needs.
One of the main benefits of fitting these type of shade screens is that not only can you still see through them but they block out flies and insects.
My point being is that it provides what is generally and unusable sapce in the sun into a usable space all year around day and night.
If I have misunderstood why you want to block out the openings then please accept my apologies.
However, if you want further info then you can contact me on 680956245