Both store employees told me that between one and three years was normal for a couch with light use.
That's why I love the EU:
The Directive on Consumer Rights
Free of charge, 2-year guarantee (legal guarantee) for all goods
Under EU rules you always have the right to a minimum 2-year guarantee at no cost, regardless of whether you bought your goods online, in a shop or by mail order.
This 2-year guarantee is your minimum right. National rules in your country may give you extra protection: however, any deviation from EU rules must always be in the consumer's best interest.
If goods you bought anywhere in the EU turn out to be faulty or do not look or work as advertised, the seller must repair or replace them free of charge or give you a price reduction or a full refund.
As a general rule, you will only be able to ask for a partial or full refund when it is not possible to repair or replace the goods.