We present the highest resolution single-dish submillimetre observations of the detached shell source U Antliae to date. The observations were obtained at 450 µm and 850 µm with SCUBA-2 instrument on the James Clerk Maxwell Telescope as part of the Nearby Evolved Stars Survey. The emission at 850 µm peaks at 4000 with hints of a second peak seen at ∼ 2000. The emission can be traced out to a radius of 5600 at a 3σ level. The outer peak observed at 850 µm aligns well with the peak observed at Herschel/PACS wavelengths. With the help of spectral energy distribution ﬁtting and radiative transfer calculations of multiple-shell models for the circumstellar envelope, we explore the various shell structures and the variation of grain sizes along the in the circumstellar envelope. We determine a total shell dust mass of (2.0±0.3)×10−5 M and established that the thermal pulse which gave rise to the detached shell occurred 3500 ± 500 years ago.