I am constructing a kitchen extension and building a new utility room and together they will form an "L" shape around the existing kitchen. The roof (which will be pitched) will be at different heights for the kitchen and utility structures so where the roofs meet, there will be a change in level and so I intend to build a small pitched cavity wall (around 1m high). In order to support the wall, I am proposing to use three concrete lintels but am not sure if my proposal will be accepted by Building Control (I will contact them to double check). What I am thinking is to use one lintel at right angles to the wall with two other concrete lintels placed on top of the first one. The brick/blockwork would then be constructed on top of these two lintels. Is that type of proposal (lintel on top of lintel) generally ok? The lower lintel would be imbedded into walls at both ends but the upper lintels would be imbedded at one end only. Do the upper lintels need to be secured in some way to the lower lintel or can they simply rest on top?