Top floor maisonette adding a garden tap

[Beth1908]

Hello,
We currently live in a ground floor maisonette and the flat above want to install a garden tap from their kitchen (below their window) down my back wall and to the flank wall (the side passage is shared).
I am fine with the principal but lacking any basic plumbing knowledge, not sure what I should check or ensure?!
Any advice or guidance would be greatly appreciated ❤

@Beth1908 why do they want an outside tap? is the garden in front of your property your private space? what happens if the tap becomes faulty and your property becomes damp? how far away is their garden area? will they have to constantly come into your area to use tap? will they pay for flower replacement of flowers damaged by hose being pulled out?

Thank you for your reply @allthemiddlechildrenoftheworld
Their garden is behind mine - the plot is split into two: my half is outside the property and theirs’ the half behind. They will therefore need to run a hose from the flank wall down the shared path and into their garden.
They won’t have to enter my garden if it’s on the flank wall but they do need to place it 6ft above ground level (not much space as the roof is pitched) so it doesn’t interfere with garden gate I’m installing (as at the moment they just enter my garden)

Tricky. The natural inclination is to try and be accomodating and agree but the more ugly pipes you have running across your walls, the more it devalues your property. Plus they can leak and stain exterior walls and possibly affect interior ones. Is it the only possible route to the flank wall?

@slippedonabanana unless the pipework is run across my pitched roof but that worries me more as it would be harder to spot if there was a leak.

When you say effect interior pipe work is there something in particular I need to watch for?
Thank you