[quote author=JerryD link=1099928320/0#6 date=1100129928]and if you take 50mm off
each tread, you end up with the top tread 700mm below the landing
???
[/quote]
no it doesnt, your only gonna get 50mm off the entire thing, each tread height( bar the top one ) doesnt affect the height of the stairs. you would have dropped the total height by 50mm only, even though you've taken off 700mm of wood. i think im talking about stringers (thats the notchy ibts right) if you take 50mm off each one then surely they would all be the same height, even the bottom one, coz you took 50mm off every one, not just the bottom edge.