Complex sentence: Donald Insall Associates are now majority employee-owned and they work from seven UK locations, as well as working internationally as both architects and consultants, and in 2015 were ranked number 39 in the 2015 AJ 120 list of largest practices in the UK.
Split into simpler sentences: Donald Insall Associates are now majority employee-owned and work from seven UK locations, as well as working internationally as both architects and consultants. In 2015 they were ranked number 39 in the Architects' Journal AJ120 list of largest practices in the UK.