COVID 19  

We are all still working remotely and self isolating due to current restrictions. Please use the existing landline number 01935 816844 and wait until re-directed, otherwise contact Derek on his mobile number 07779172996. All our emails are working and we will endeavour to reply or call you back if requested. 

Williamson Structural Design is a Structural Engineering Company based in Sherborne, Dorset.  We provide structural design solutions for construction projects including listed building conversions, extensions to modern and period houses and advice on traditional timber frame structures.  We have been based in Sherborne since 2005 working closely with designers, architects and builders.  We also offer the following services:

  • Structural Surveys of modern and period properties
  • Green and brown field sites
  • Building Conversions (i.e. Extensions and alterations, Barn conversions, Residential)
  • Traditional or timber framed dwellings
  • Apartment blocks
  • Industrial and Commercial
  • Steel framed warehouses/offices and agricultural buildings



Derek Williamson       BEng CEng MIStructE 


I have been an engineer since 1988, training in Dundee.  Originally from Scotland, I moved to Dorset in 1997 where I became a fully qualified Chartered Structural Engineer and Member of the Institute of Structural Engineers.  I set up my own practice in 2005 in Sherborne where I have been working for local communities and clients across the south west.

Michelle Crossley


Michelle joined us in 2019 as Office Manager .She deals with the day to day running of the office and manages our sales, invoices and accounts and keeps the office running smoothly.


Jo Massey       MA CEng MIStructE


Jo graduated in Engineering and Law from Cambridge University in 1989, becoming Chartered in 1995.  Her experience varies from large, high profile, London based projects to agricultural buildings designed to earthquake codes in New Zealand but her experience also encompasses domestic, medium sized and historical projects.  Jo joined the company in 2012.



Steve Terry


Steve initially started as a structural steel draughtsman and has 40 plus years experience working with local engineering consultants in the area. 




Tom Latimer


Tom joined us in 2018 and has developed his AutoCAD and design skills to become an essential part of our team.