Thats what it says on Richard burbridges wed site may be different for other makes/designs.

http://www.richardburbidge.co.uk/downloads/BRACKET_INS.pdf

Jason

That way is the Richard Burbage way, but not the only way.  It works as long as your old Newel is the same size as the new or you have to start rounding over the end of the old newel to make it a feature.

You can just buy Full Newels and totally replace them depending on how they are fixed and your skill level.

Please post any questions i will help if i can

Coggy

Ok cool, yes the measurements you say are what Richard Burbage recommends.  How he gets these measurements im not sure but i have the video and he does recommend them.

The link Jason B posted will give you all the info you need.

Coggy

It is a bit weird Keith i agree  ??? The Richard Burbage instructions does give them measurements and shows you where to measure from etc etc.

But im not sure what gives them this measurement and why etc etc

The RB website does give all the instructions though, i dont use there materials fixings etc because i use that small family business nearby which sells all different types (Including RB)

Coggy

surely this will only work with RB parts as the measurements are to ensure that the squares at the top of the newels are at the correct height for the handrail to be 900mm from the pitch line.
If using anything else then measure from the shoulder of the new newel post, at the bottom up to where the top of the handrail will sit and the take this away from 900 and that is the height above the pitch line at which you need to cut off your existing newel bases. you can use the burbridge method for determining where this height falls on you existing post.