Rent Reduction as compensation for building works help

Rent Arrears

We are finally getting our building remediated with proper fire cladding. These works will be the entire block from Jan to November next year with scaffolding across the entire block with netting which will restrict light and view from balconies and windows. Works will take place from 8-5pm Mon-Fri and are expected to be disruptive as they strip the building and put the cladding in then put everything back together again. Its due to happen in stages with scaffolding going down in sections from May, Aug and Sep as they complete the works.

Im looking to understand how best to calculate a rent reduction for my tenants during this disruptive period. Im sure there are many other landlords who have been in this situation post Grenfell and the number of apartment blocks that have had to undergo these works so hoping there is something I can benchmark on!

Many thanks in advance!

Thanks
Natasha