Inset gas fire query

[john9159]

Can someone please indicate what exactly is involved when fitting an inset gas fire into the existing fireplace of a 1930's house.
I am removing a free standing gas fire and intend to have an inset type fitted; I already have the restrictor fitted to the floor next to the hearth but once the inset is fitted, how does the fitter connect the gas supply to the inset as I have never seen any external piping?

Also, how efficient are inset gas fires as this will be the only source of heat in the living room.

Thank you

[htg engineer]

The pipework come from behind and is hidden - alot of heat is lost up flue - best fires for heat are radiant gas fires - but look dated.

htg