The extrapolation of energy confinement to the conditions of a Next Step tokamak, to operate with an ignited DT plasma, is an essential ingredient of the data base needed for such a device. The present knowledge on energy confinement and the approaches used for providing a basis for the extrapolation are concisely described. The lines of further research are indicated which have to be followed to be able, in a few years, to extrapolate energy confinement to a Next Step tokamak with improved accuracy.