An entity acquires an office building for 6,000,000 (excluding land). The technical expert provides the following breakdown: structure 4,200,000 (50 years); roof 600,000 (25 years); heating, ventilation and air-conditioning 700,000 (15 years); two lifts at 150,000 each (20 years, same depreciation method); various small fittings 200,000 with varied lives. Write a judgement memo on the breakdown to use for depreciation.