The cost of the construction was largely to be borne out of normal laboratory funds (in this case the budget for the subsidiary course teaching laboratories); the tunnel was required to be suitable for mounting first year student projects without sophisticated safety requirements, and was designed to occupy the minimum area of useful floor space commensurate with the additional facilities which it would provide. In addition, excessive noise and draughts were not acceptable to those students using the existing services of the laboratory, and as no specialist labour was available for the construction of this tunnel, its design needed to be fundamentally simple.