He has a practice based in Sydney with ten staff. He has had a focus on industrial heritage since writing an undergraduate thesis on NSW railway architecture that was awarded the NSW University thesis prize. Since that time Paul has studied, recorded, restored and adapted industrial sites including hop kilns, hydro sites, power stations, fortifications, light houses, railway sites, water reticulation sites, gas works, maritime sites and shipyards, rural and farm sites. He has also undertaken many heritage studies, both thematic, such as the Tasmanian Hydro power system, and regionally based, currently completing the Campbelltown heritage study in Sydney. The thematic studies have specialised in industrial and engineering heritage.