Complex sentence: From 1973 to 1978 he worked in the architect's office of Albert Viaplana and Helio Piñón and whilst there--among other things--he was involved in the construction of the "Plaça dels Països Catalans", the forecourt for the "Estació de Sants".
Split into simpler sentences: From 1973 to 1978 he worked in the architect's office of Albert Viaplana and Helio Piñón. Whilst there--among other things--he was involved in the construction of the "Plaça dels Països Catalans", the forecourt for the "Estació de Sants".