question 1: I have a flat which is first floor and ground floor entrance. The ground floor has a small entrance and straight up the stairs. I understand I have to have detection on every floor, but the area downstairs is to small to install a detector ( 12 inches from wall and 12 inches from light fitting ). Should I just put one close to wall?

There is also no feed from the light so can I put a battery operated smoke detector in?

Question 2: My other flat has is also first floor and ground floor entrance. But this one has a double height ceiling. so the smoke detector for the ground floor would effectivly be on the first floor ceiling! No electric feed here either?? Can a battery detector be fitted and linked in with flats hard wired kitchen and hall detectors?

I can't find answers to these 2 specific questions anywhere.

1 - A stair landing with no rooms on/off it does not need a detector to meet The Smoke and Carbon Monoxide Alarm (England) Regulations 2015 (as amended)

2 - You can't usually link Grade D (mains) & Grade F (battery) alarms. However it sounds like the flat already has the legally required detection & under answer 1 does not need the additional one.

The regulations state that a hall or landing would be classed as a room and that The regulations require a smoke alarm to be installed on every storey of the premises on which there is a room used wholly or partly as living accommodation. So because a entrance hall is not living accommodation then a smoke detector is not required, is that what your saying? If it is what your saying, that's top knowledge!

Also, the flats are in wales and the welsh rules are the Fitness for Human Habitation part of the renting homes wales act 2016.

Which states " The FFHH Regulations require a landlord to fit a working smoke alarm on every storey of a dwelling. The alarm must also be connected to the electrical supply and be linked to any other smoke alarms that have to be fitted under the regulations. Smoke alarms should be fitted where they can be heard by the occupier when asleep, usually a hall or landing area.

More than one smoke alarm may be fitted on each storey. If so, it is good to have all alarms inter-linked and hard-wired into the electrical supply. However, if the landlord has met the minimum requirement of one hard-wired and inter-linked smoke alarm on each storey, any additional alarms do not have to be inter-linked and can be battery powered."

Therefore does ' STOREY' mean the same in wales as it does in england? If it does I am ok but I can't find a definition for the renting homes wales act?

Wales seem to count a hall, landing as a habitable room🤦‍♂️ and so need a hard wired detector on each floor ( even though there is no room for one between wall and light fitting)

Ah - Wales! Very different then!