STRUCTURE: INTERNAL AND EXTERNAL
Structurally speaking, the Museum of Childhood is a superb example of a mid-Victorian iron and glass building. However, the works recently completed have less to do with its original structure than with its external envelope and entrance. The building was commissioned following the Great Exhibition of 1851 and originally stood in South Kensington on the site of what is now the V&A Museum. Conceived as a temporary structure, it was clad mainly in corrugated iron and received an overwhelmingly hostile reception on its opening in 1857, becoming known as the 'Brompton Boilers'. In the 1860s, plans were drawn up for the construction of permanent buildings on the South Kensington site and the building was moved to its current location in Bethnal Green. J W Wild designed new brick facades and added an entrance colonnade on the west side. Our first involvement at Alan Baxter & Associates was to help deal with access for roof maintenance. The roofs are slate and timber, supported on delicate iron trusses, and it was necessary to devise a system that could cope with significant variations in the positioning of the existing rafters and purlins. The next phase of work created temporary access into the inadequate existing colonnade for DDA compliance while the design of a new entrance was developed. The latest phase of work has been the construction of the new entrance building.
The structural-engineering design makes important contributions to the architecture of the new building. On the ground oor the walls support exposed roof beams made up of steel - ns that create a strong visual pattern of light and shade. Around the perimeter, the roof structure is carefully coordinated with the internal linings and has finely detailed hidden connections.
At basement level, the concrete ceiling has a high-quality formed finish and is exposed to help maximise head height; the columns are of precast concrete and also exposed. Externally, the reinforced-concrete retaining walls around the courtyard areas are constructed with a black basalt aggregate and have been polished on site to allow the colour of the stone to be revealed.
These match the precast-concrete panels set into the stonework of the front facade. Close working with the architect from the inception of the design has helped to achieve a superb result.