How to demolish concrete wall / precast concrete wall / reinforced concrete wall / brick wall? How to break down concrete wall?

Vertical holes located in the middle of the wall thickness (drilled from the top) are the best solution. The holes are drilled to the planned demolition level to perform demolition in one step (with long drill bit) or in several steps (shorter drill). It is best to fill every other hole in one step and fill remaining holes next day.
Hole diameter: 38-40 mm in heavily reinforced concrete, 32-38 mm in lightly and non-reinforced concrete, 30 mm in brick or non-reinforced concrete in temperature above 10 deg C, 25 mm in brick walls up to 20 cm thick (T > 10 deg C). Hole diameters smaller than recommended are also in use however time to damage is longer.
Hole spacing: between 1 and 2 times wall thickness. Beginning bigger job it is worth to initially test differnt spacings to obtain uniform cracks distribution in entire volume of the wall. Greater spacing generates better results often:

Approximate consumption of Dynacem for various types and thicknesses of walls demolition is given in the table:

When it is impossible to drill from the top, the holes are drilled from the side, in square drill pattern.
Minimal drilling depth: 5 times hole diameter.
Hole spacing should not exceed 30x30 cm if the rubble will be removed manually or with hand tools. Larger hole spacing, e.g. 40x40 cm, can be used when larger chunks will be removed by the excavator. Hole spacing should not exceed 10/15 diameters (reinforced concrete, hard stone/concrete and bricks).
Inclined holes are easy to fill with liquid Dynacem mix. Horizontal holes can be filled with plastic consistency mix (it is time consuming) or PVC elbows can be plugged into the holes and liquid mix poured through them:

Find galleries of pictures demonstrating demolition of different walls here.