Water Pressure Help

I am going to try the various ideas although I have tried all these before, the only problem I have is that all the meters are kept in a pump house and I have asked before if all the valves are open and was told yes to the max. The stop cock in the house is situated in the downstairs toilet next to the hot and cold valves. I am at a total loss and I think it might mean putting a pump on the cold water supply but will need to investigate gate this with a plumber.

Depending on age of property the pipes could be partially blocked with scale which can be a big problem! If inlet pressure and flow is good after the meter (coming into property) then problem is in pipes or valves sometimes with age valves will not open fully especially if the property has been left not lived in for years!