NSW Tenant request for rent reduction due to neighbour renovating

[Nica]

Hi, I am the landlord of a semi that is currently rented. The lease is up for renewal in April. The neighbours with whom we share a common wall are renovating and adding a new storey to their property. They have DA approval but still no exact start date. We informed our tenants as soon as we knew and opened conversation about whether they would be willing to stay on. They are now asking for a $480 per week rent reduction from current rate of 1550/wk rent for the duration of the entire works, based on the grounds that they each work from home 2 days a week, totalling 4 days/week. They will not lose access or usability of any of the rented property, but there will be noise. We would consider a rent reduction, but this seems like a large amount and the impact of the construction will also vary across the project. I would like to know what their and our legal rights actually are and appropriate amounts of rent reduction based on noise (the biggest problem), and potentially dust. Thank you