[Paul Coleman]

Combination padlock/entry pad.

I have commercial and domestic customers who supply me with the numbers. If it's worthwhile why not buy a combination padlock for sidegates?

I have an arrangement like this for a few jobs too.  None of the jobs were valuable enough for me to justify paying for the combo lock but a few of them took my suggestion on board.
If they go along with it they can have their security and their windows cleaned.  If they don't, it may mean that they don't trust you personally (or it may mean something else).

[Londoner]

Access and people not being in are my two biggest problems. Very few houses have someone in most of the time these days and gates left on the latch are rare.

So far as access goes WFP is better than trad. As long as you can get a hose down the side somewhere you are in business. No more lugging ladders through the house or through garages piled high with junk.