The blaze broke out at an address in Pepper Lane, Thurston, just before 9pm.
More than 50 firefighters are at the scene from stations in Needham Market, Stowmarket, Wickhambrook, Bury St Edmunds, Elmswell, Ixworth, Mildenhall and Newmarket.
An operational support vehicle from Ipswich East is also in attendance, as well as The Salvation Army, providing refreshments to the crews.
Retained firefighters from other stations across the county have also been put on standby in case the fire worsens.
Updates from Suffolk Fire Service described the thatch of the two-storey building as 'well alight'.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here