Unfortunatley Foam Structures are not so popular in the UK. 

(Source) Shows a house in Phoenix Arizona using extruded polystyrene and polyurethane spray foam adhesive to join them together. This method is not popular in the UK yet as it has not passed the health and safety rating system; in particular regards to fire safety. Extruded polystyrene or EXPs was also used in the original foam igloos in Nunavut in 1949; this project resulted in the death of double amputee Eskimo Kingwatsiak so - we use PIR instead as on a small scale it is inflammable and non-combustible; further we do not use any combustible adhesives; to join the coatings to the PIR; as we learned from the Grenfell tradgedy.

PIR was used in Grenfell as it has always thought to be incombustible; however it just had never been fire tested on a large scale; therefore we can say our igloos are incombustible as they are small scale projects. 

(Source) Shows foam being joined with more foam; this was a significant breakthrough in foam sculpture and foam building; when material are joined together the adhesive needs to be a similar chemical makeup to make that chemical bond; 

PVA is Vinyl Acetate; and Acetate is an organic hydrocarbon alcohol that dissolves and binds to the hydrocarbons in the cellulose; so we also call PVA - "wood glue". 

Mortar is a cementitious binder