Local contractor Jenkins Weir is to start modernisation work at Northampton Museum and Art Gallery today (5 December), which is due to be completed by the end of March 2012.
The attraction will remain open throughout the duration of the project, which will lead to the provision of more flexible exhibition displays and a re-fitted ground floor.
Renaissance funding totalling £113,000 has been contributed by the now-defunct Museums, Libraries and Archives Council, with Northampton Borough Council also funding the work.
Council cabinet member for museum Brandon Eldred said: "Museums are operating in an increasingly competitive market and we are rising to the challenge to give visitors the quality of services they rightly expect."