Putting the art back in to old buildings

by Graham Ridout



One of the most important art collections in the world will open to the public this Friday (26 May).

The collection of decorative arts, a gift to the nation by Sir Arthur Gilbert, is housed in the restored Embankment and South buildings that form part of Somerset House.

The £25m restoration of the 200-year-old Grade 1 listed (and listing) buildings has not been without hardships, but the end result is a magnificent museum that is equal to the 900-plus gold, silver and micromosaic exhibits that constitute the Gilbert Collection.

Simon Davis, of construction manager Heery International, explained: "There is not a straight line in the whole building and it has been literally slowly falling down since the day it was built."

The Embankment building was completed in 1788 and was built in the Thames on wooden piles. It featured the Great Arch, under which boats passed into an enclosed dock within the grounds of Somerset House.

Virtually from day one, the building stated to move and rotate towards the Thames.

This movement continued until the Embankment roadway and sewers were formed in the late 1860s. These acted as a buffer between the Georgian facade and the river.

One third of the height of the original facade was covered by backfill during these works and although this helped, the building continued to move and settle.

To arrest any further movement of the brick vaulted ceilings, Heery in conjunction with engineer Oscar Faber, devised a system whereby a 325mm thick reinforced concrete deck was constructed to act as a structural staple to tie the front and back walls together.

At the same time, the fill between the foundation walls under the original basement was removed.

The 6m deep excavation was then replaced by a 4m square concrete box with 300mm thick walls that ran almost the entire length of the building.

This served two purposes: as a low-level structural prop that works in tandem with the concrete staple deck, and as a plant room in which all the air-handling and chiller equipment for the new galleries above could be housed.

"The hardest part of the project was inserting all the mechanical and electrical services", said Davis

Some smart thinking has seen the air-conditioning being fed into the galleries through the existing fireplaces wherever possible, or via fan coils located discretely in alcoves in front of the windows.

In other areas, full height air-conditioning units have been installed in the galleries, but each unit had to be a different size to meet the varying geometry of the rooms.

The increased floor loading required for the change of use from office space to a museum meant that the floors had to be strengthened in areas of the South building.

The existing floorboards were lifted and steel flitch plates cut into the Baltic pine bressumer beams.

By electing to do it this way, architects Peter Inskip and Peter Jenkins were able to leave intact the original plaster ceilings below.

In the Embankment building, a new mezzanine floor was added by inserting padstones at the springing point of the vaulted ceiling, onto which a new steel floor deck was erected.

One of the prime considerations throughout the 29-month design and construction phases was ensuring that "all the work respected the historic fabric of the buildings".

This is particularly noticeable when dealing with the services. For example, no lights, security cameras or other paraphernalia have been fitted to the main vaulted ceiling of the Embankment building.

In all, 39 works packages were placed which, Davis said, "involved everything from demolition and heavy engineering to fitting out the gift shop".

Another consideration that had to be overcome occurred when working with the lathe plaster. Horsehair had been added to give strength to the plaster and samples had to be sent for analysis to test for anthrax.