Complex sentence: Reconstruction of the Quadrant was finally carried out by Sir Reginald Blomfield, who adapted and arguably watered-down Shaw's designs; building works started in 1923 and completed in 1928.
Split into simpler sentences: Reconstruction of the Quadrant was finally carried out by Sir Reginald Blomfield, who adapted and arguably watered-down Shaw's designs. Building works started in 1923 and completed in 1928.