Asking tenants to move out temporarily during alterations to buildings during tenancy

Other

Hi

As a share of leaseholder, I'm not allowed to unreasonbly deny alterations to the building according to our lease agreement. I own a flat in a period property conversion. The ground floor flat has the garden. Mine is the 1st floor flat. 

The lady who owns the flat below (share of freehold) is about to do a ground floor extension into the garden. She plans to take out the bay window, just below my bay, they are part of the same bay. 

My concern is that it might be the builders say my flat is unsafe for people to live in it while the bay structure is being removed on the ground floor. This happened next door to me, the builders asked the owner to move out and said it was unsafe for 2 weeks while they did the garden extensions. 

What should I do:  

(1)  say I won't grant a license to alter as asking my tenants to move out for an extension that has nothing to do with them is unreasonable?  This will make the owner very upset, and the other freeholder could override me as they only need two directors to agree something and sign in a company meeting. (the freehold is a company)

or

(2)  tell my tenants, sorry, but you have to move out for 1 week/ora few days (as the builders requires) and I can't do anything about this? And ask the lady downstairs to find them accomodation for this ?  Can I do this in law and what if the tenants refuse to co-operate?  I assume they don't have to co-operate? I have a clause in the tenancy making the tennat subject ot the head leased so I guess they also can't unreasonably deny alterations,.

How common is this and what would you do?  Any guideance would be helpful.

BTW I'm about to advertise and get new tenants so this is not the sort of thing i can talk about with the tenant yet as I'm not sure who the tenant will be. Also I haven't been told about timing of the extension yet although I have seen early plans.