Bott will officially open its £1.1 million extension to its Ashby de la Zouch van fleet conversion and enhancement centre at a special event on September 15.
The new building will add 13,000 sq ft to its premises and will create about 20 new jobs.
Ken Woodward, managing director of Bott's vehicle enhancement division, said: "Our latest expansion brings our total investment in the site to around £5 million."
The German-owned company, which also has operations in Ashby, Bude in Cornwall and Glasgow, as well as Bott-owned facilities in Germany and Hungary, creates the interiors for fleet vehicles for companies such as Sky and Virgin Media and works on projects from specialist bomb disposal vehicles to command units for the fire brigade.
Its clients also include the Environment Agency and Severn Trent Water.