Inn searching for an expert to carry out for you as a company 33 kv substation design you need to consider different factors .First you need to consider the economical part of it. Let the design that you will come up with be economical. You need to look for an expert who will be able to produce the best design for you to realize a profit in using the design. On the same point of economic consideration you should look for an expert who is willing to carry out for you 33 kv substation design on a reasonable cost.
For you to achieve this you need to be well informed on the cost of designing the substation in different designing firms. Secondly you need to consider the ability of a designer to achieve the best in designing. You need to contract a designer with a good background in designing. Let the designer that you contract be able to give out credible examples of designs which he has worked on before.