Blindness charity Guide Dogs grew income by a third to over £100m, thanks to property sales worth more than £17m, according to its most recent accounts.

The charity also saw a signifcant boost in voluntary income, which  increased by 15 per cent to £75.9m.

A statement in the charity's latest annual report said much of this was legacy earnings, which had “exceeded expectations”.

Some £17.2m came from profits from the sale of the charity’s Wokingham site. The site is an obsolete charity training centre and will be used for a housing development.

In July, the charity’s head of property services Roz Gratton, said the charity was moving to a new head office as part of an efficiency campaign, which could also involve more property sales. She said Guide Dogs owns propery around the UK and is looking at whether its portfolio can be used more effectively.

The charity will also integrate property, HR and IT services as part of the strategy but has yet to decide on a new head office location, Gratton said.

The charity bred just under 1,500 puppies and placed guide dogs with 847 blind people. It now provides guide dogs to just under 5,000 people.

It is expanding a new "buddy dog" service which involves dogs that do not qualify as guide dogs, and is also recruiting more human volunteers to act as guides for blind people.

Staff costs also increased over the year – at £47.7m up from £42.9m the year before – with the charity’s highest earner taking home between £130,001 and £140,000.