Complex sentence: In August 1769 Turst purchased a leasehold house on the west side of Poland Street which backed on to the site of the Pantheon and built a secondary entrance there and this unbudgeted cost added more fuel to the legal fire.
Split into simpler sentences: In August 1769 Turst purchased a leasehold house on the west side of Poland Street which backed on to the site of the Pantheon and built a secondary entrance there. This unbudgeted cost added more fuel to the legal fire.