Cutenut

thanks for the reply.I guess for England this will not apply as its a NI originating document. ☹️

ETC can you tell me from what document you are quoting and is it a UK released one? Can you provide a link to it? I could not find this reference in Part M or K and no mention of it on the NHBC website. (I have a similar situation where we are extending a bungalow with a sloping/falling garden and the finished floor is some 70cm above. To put a zero threshold leading onto a patio stepped to the garden we are being told conflicting information. ie, take the drop measurement from the original build line which is 30cm and proceed without guarding, or step each following patio area by 220mm risers until the base of the slope is reached, each terraced area being at least 60cm across.)