Screed or TeckWarm Insulation Boards (upper floor)

[North Coast Self Builder]

 

Hi folks,

Interested in opinions / guidance on the cost and performance differences between using screed and not on upper floor.

Architect has specified a dry build up using these boards. I've been told this is a very expensive route vs screed and also the thermal performance not likely to be as good if screed not used. 

Cost is definitely an important factor for us at this stage. 

Are to be covered will be about 120 square meters.

Any thoughts and experience welcome.