i have not longed moved into a council house that has metal door-linings and heavy-duty butt hinges. (ugly things)
i've been told that these particular frames were put up along side the brick work and imbedded some-way into the mortar with butterfly-bolts; the frames take-away the need for lintels. The work possibly dates back to the 70's.(so i've been told)
Can anyone tell me if this is the case, or might the builder be mistaken and the neccessary work to remove and replace them would be someting simular to that of your average wooden lining. A lot simpler.