Positive force in building? That's the ideal state (10)
I believe the answer is:
perfection
'the ideal state' is the definition.
'perfection' can be an answer for 'state' (perfection is a kind of state). I am unsure of the 'the ideal' bit.
'positive force in building?' is the wordplay.
'positive' becomes 'p'.
'force' becomes 'F' (symbol used in Physics e.g. f=ma).
'in' indicates putting letters inside.
'building?' becomes 'erection' (erection is a kind of building).
'f' inserted into 'erection' is 'erfection'.
'p'+'erfection'='PERFECTION'
'that's' acts as a link.
Can you help me to learn more?
(Other definitions for perfection that I've seen before include "Faultlessness" , "Highest state" .)