The Northumberland building, a typical 1960’s office block, needed refurbishment because the existing pre-cast concrete cladding was failing. It was fitted with a new solar facade, an integral photovoltaic cladding system which is one of the largest in Europe. This was completed in January 1995 and will provide fifty per cent of the building’s electricity requirements in the summer and ten per cent in the winter. Over a year the facade will generate thirty thousand units of electricity, equivalent to thirty per cent of the building’s annual electricity needs 16.

The facade will produce CO2-free electricity over the course of its twenty – five to thirty year lifetime, saving the emission of one thousand tonnes of the gas 17. It will generate electricity that would normally have cost £30,000 at today’s prices.

The solar cladding has been installed on the south side of the building and inclined at 25 degrees to the vertical, maximising the winter sun output.