Art Deco

Grade A Listed Building


Centre of Edinburgh

Conservation Structural Engineer

PDP Consulting

Contract Manager

Ross Renton

The Brief

MPACT was appointed by PDP and their facilities management client to carry out stabilisation, repairs and repointing of the stonework to this dramatic art deco building. The primary reason for the instigation of the works was the finding of corrosion in the steel frame of the building. Further inspection clearly showed that repairs to the stone cladding on all six floors would be required.

Our dedicated staff of stonemasons have worked on several Grade A listed buildings, locally and further afield. Their expertise, which covers restoration and conservation as well as specialist pointing and rendering works, ensures that we deliver a first-class finish. Being able to demonstrate this was the main reason we were asked to work on this project. As a company, we work alongside conservation engineers throughout the UK, who are well-versed in the intricacies and demands of restoring structures of this type to a precise finish.

For this project, we were called upon to prepare a historically accurate mix of mortar and sand for the pointing works. This aspect, crucial to the integrity of the building, required sign-off by the conservation engineers overseeing the works, before the task could commence.


The property, built on the site of a building demolished in the 1920’s, is an outstanding monument to international architecture’s Modern Movement. When it was opened, it was the largest metal-framed building in Europe.

It has been in constant occupation since and is now an office building housing some 800 administrative staff and conference facilities.

Replacement stone for larger repairs was obtained from the original quarry in Northumberland, which was specially reopened for this project. The MPACT team cut and shaped the more ornamental stonework under the direction of the conservation structural engineer.


To prevent further corrosion of the steel frame we were directed to encase wiring in the pointing which in turn, conducted an electrical pulse to the point where the mortar met the metal framework.

The process, which is known as Impressed Current Cathodic Protection [ICCP] is similar to the system used on ocean-going ships to prevent sea water corrosion of their hulls. It is one of the few occasions on which it has been used on a building of this size.

The large scale ICCP project has been designed to suppress the corrosion process, which along with the other measures, should ensure the building continues to provide high-quality accommodation for the foreseeable future.