It is crucial that you always take time to examine a web design agency's portfolio so that you are able to gauge what type of work they do as well as determine their specific design style. Additionally, it's imperative that you seek out an agency that targets your particular market or industry as they will have much more expertise and can offer a more accurate quote for the type of project that you have. The agency that targets your specific market will be able to set a realistic and definitive deadline.
Is your agency doing all of the design work?
These days, it's not uncommon diseño web barcelona for a design agency to outsource quite a bit of their work to freelance designers in other countries, such as India. You're paying "top-notch" designer rates but you're actually getting work done by whoever will do it for the least amount of money. Make sure that you know exactly who is doing ALL the work for your project. Insist that it remains in-house and have that detailed in your contract.