I believe that any wall lower than 1.2m does not need to be designed by a structural engineer. With that in mind I am proceeding to design a retaining wall no higher than 1.2m. Length 7.5m. Piers on either end. Costs are a key issue, and I'm wanting the face to be brickwork. I know the depth of the wall needs to be about 300mm. I have an assumption that it would be cheaper to build a wall of concrete with the brickwork as facing. Rather than the alternative of a wall made completely of brickwork. QUESTION: Is my assumption correct? QUESTION: Assuming I'm to make a largely concrete wall, can I build up the wall in stages? That is, lay courses of brickwork, pour the concrete behind, lay another course of brickwork, pour concrete etc. QUESTION: Is concrete water resistant? By and by I'll post a picture of my final design so that folks can verify it is adequately designed. Any suggestions of a cheaper method of construction that retains the brickwork facing will gratefully be received. Thanks.