Mae'r system ym Mhrawf 4 yn debyg i'r cyfuniad sydd ar bedwar adeilad sy'n berchen i Ddinas a Sir Abertawe. Mae samplau o'r rhain wedi'u profi'n flaenorol gan y BRE. Pasiodd y system a brofwyd y prawf, ac mae hynny'n ddatblygiad cadarnhaol. Wrth gwrs, rhaid i landlordiaid a pherchenogion barhau i fanteisio ar bob cyngor a chanllaw arbenigol sydd ar gael iddynt mewn perthynas â'u hadeiladau.
The system in Test 4 is similar to the combination in place on 4 buildings owned by the City and County of Swansea, samples of which had previously been tested by the BRE. The tested system passed the test, which is a positive development. Of course, landlords and owners must continue to draw on all expert advice and guidance in relation to their individual buildings.