Excess, or deductibles, is a set amount that the insurance holder has to pay before the insurance company compensates the rest of the claim. Insurance companies enforce this so the policyholder will practice diligence towards home maintenance and the general up-keep of the property.
The formula is simple – the higher the excess the lower the premium. Though higher excess might make sense in the short term because of the significant lower premium, it is not recommended for the long term as you have to pay a greater amount out of pocket in cases of higher excess. So, if you want the insurance company to pay more of the claim go for lower excess.