The National Theatre (NT) has reported a "strong financial year" for 2010-11, with income increasing by nearly 9.5 per cent to more than £70.6m thanks to strong attendance figures.

In its annual report, the organisation revealed its production of War Horse at the New London Theatre had generated £13.9m at the box office and a surplus of £2.9m alone.

Attendances for War Horse averaged at 97 per cent during the 12-month period, with attendances at shows staged at its South Bank home averaging 90 per cent in 2010-11.

The surplus generated by War Horse has now gone towards the NT Future project, a planned £70m redevelopment which the organisation said is now at the detailed design stage.

More than £30m has been secured towards the total cost of the scheme, which has included a £10m gift from NT board member and Travelex founder and chair Lloyd Dorfman.

The NT's contribution currently stands at £5.7m after its strong 2010-11, while the Clore Duffield Foundation has donated £2.5m towards a new Clore Learning Centre.

London-based architects Haworth Tompkins have worked with the theatre on the proposals, which aims to open up the South Bank venue to more people.

Image: Aurelien Guichard