1. First, measure and evaluate inconsistent walls. Determine the height, length, uneven position and characteristics of the wall. This will help to determine the size and location of the shed.

Secondly, find a horizontal datum line on the wall. You can use a spirit level or other tools to ensure that the shed is built straight and level. Align the shed with the wall by adjusting the height of building materials or using adjustment tools.

3. Then, according to the unevenness of the wall, the height and levelness of the shed can be adjusted by adjusting tools and materials, such as supporting plates and adjusting wall columns. This can provide a more stable and flat foundation on inconsistent walls.

4. Then according to the inconsistency of the wall, you can choose to design sheds with different heights and lengths. For example, multi-layer design or the special shape of the wall surface is adopted to adapt to the uneven wall surface.

Finally, if you are not sure how to deal with the disharmony of walls or lack of architectural skills, you can seek the help of professional architects or engineers. Can provide professional solutions to ensure that the design and construction of the shed meet the safety and stability standards.