All four phases speak with their own voices, but the result is more of a conversation than an argument. Burnet's original building can still be seen and appreciated; its companions – with the exception of the entrance bay – do treat it with the deference it is due. The subsequent architects did generally take sufficient notice of what was already there to ensure continuity in what followed this is particularly true of the combination of simple well proportioned spaces, exposed roof trusses and excellent levels of daylighting which are something of a standard throughout the building.