Some say residential block insurance has gone up substantially 'because of Grenfell' or because of 'an increasingly difficult market' which has seen fewer companies prepared to take on this business. However, with a small 'shared house', most regular companies and brokers will offer something, and, as others have suggested, getting a range of competitive quotes is always a good idea, if only to concentrate the mind of your existing provider. Also, be clear what your block insurance needs to cover and what should be covered by individual leaseholders within their own flat. You can also reduce the premium by increasing the excess, but that can cause its own difficulties.
Peter Evans ● 726d