Whenever you order a Timber Venetian, we always check if Hold Downs have been requested. And if they have then we pay close attention.
Hold Downs need more clearance
When reveal fitted, a timber venetian typically is made with 10mm clearance from the window sill (or floor). However when hold downs are specified, a 25mm clearance is needed for its proper operation.
Face fitting is not an issue unless the venetian goes all the way to the floor.
Customers are often not aware of the light gap that a hold down can cause, and we have had people regularly change their mind. So you need to be mindful of the impact of a hold down.
Next time your arranging a timber venetian for your customer, if they want hold downs, remind them of the 25mm gap that is needed.