Regardless of whether its mandatory or not,you would be nuts not to get a survey done on a 100 year old house.
Property health check are an excellent company,dont have the number to hand just google them though.
Fair point Knuttell, Yes I intend getting a Structural survey done and can use it to bargain if necessary afterwards.
I just don't want the Bank demanding one and delaying/ compromising the mortgage amount over unnecessary stuff which I am prepared to overlook as the house looks like it can be got for a good price.