Thanks for replies.
Seems general consensus is that retest every change of tenant is resonable. I am mindful that most of you on here are electricians and naturally thus see it from the perspecitive of the ultimate electrical safety. From a landlords perspecitve it's more about running a business thus keeping costs down and margins up and risks to acceptable levels while complying with legislation.
I take the point that a tenant may interfere with the electrics though once you start down this road there are lots of risks which it becomes impractical to cover off. Did the tenant leave his collection of poisonus pet snakes in the attic? Perhaps as part of a terrorist movement they left their stash of anthrax/novachoc etc tucked out of sight under the kitchen sink or in the toilet cistern etc. Point being without virtualy knocking the building down and rebulding it you can't be 100% certain that the tenat didn't do or leave something that presents a risk to a future tenant.
Things like changed light switches or sockets should come up on an end of tennacy check out report which would then invite further investigation and thus an EICR for a prudent landlord.
I found the following guidance from NAPIT which confirms it's grey in their eyes:
Q If my property already has a satisfactory Electrical Installation Safety Report which is less than 5 years old, do
I have to get another one done to the 18 th edition of the Wiring Regulations Standard?
A
Not necessarily. You should review your report to see what was recommended on it and consider how your property
has been let since it was carried out. If big differences to the property have occurred, e.g. high turnover of tenants,
DIY work found, flood damage, then it would be prudent to get another electrical safety report done. If no changes
have been made, then your report will remain valid until the next inspection date specified.
Regarding starting from scratch at the next retest - I am sure you would be. For a start there is the 10% test/lack of overlap issue. Then there is the liklihood that we will be on the 19th, 20th etc wiring regs by the time of the retest. Also my experience of the gas saftey is that one engineer passes it one year, another engineer passes it the next year then the following year another engineer raises an issue which relates to the installation and was pre-exisinting thourhg the prior to tests and so fails it.
