Sometimes clients decide to hire an interior decorator or designer once their flat has been handed over by the developer. A shell and core flat already has electrical and plumbing systems fitted, but this does not mean that this stage of the project can be skipped. Both the electrical system fitted by the developer – in a very basic state – and the plumbing system are adjusted to a specific design, i.e. a specific layout of furniture, equipment and lighting. The developer does not know what the interiors will ultimately look like, so they are unable to fit the necessary connections in a way which does not require any changes.