Home insurance no claims discount - how does it work?

Not quite; unlike car insurance, home insurance providers don’t distinguish between ‘fault’ and ‘no-fault’ claims when it comes to discounts. If you don’t claim in a 12-month period, you could benefit from a discount for the following year. 

If you’re intending to claim for a small amount, such as minor damage or theft of a low-value item, you could lose your no claims bonus, so you might prefer to not make a claim, especially when weighing up the cost of your excess too. It may be cheaper to pay for the replacement or repair costs yourself.

If you’re claiming for a considerable amount of damage or high-value theft, then you’re probably better off going ahead with the claim. It’s up to you whether it’s worth making a claim or not. Remember to consider how much excess there is, and any possible premium increases if you do claim.  
Making a claim on your buildings insurance usually won’t affect the NCD on your contents insurance, and vice versa. But always check your policy to be sure.