i have an older home built in the 1950, recently had a pro replace all the old aluminium type windows except for the basement windows which are approx 32x17".they did not replace the basement windows, as they were supposed to be encased in a steel frame and advise it would be too costly to replace, my neighbour, did his himself,with very little problems. what is the best way to replace that type of window with steel frame encased in concrete?should i use a 1/2" or 1/4" wooden frame prebuilt around the concrete, or any other ideas would be appreciated.