Sheffield Civic Trust is encouraging owner of interesting buildings to consider being involved in the Heritage Open Days, this year being on 11 – 14 September. This is when buildings of interest make themselves available to be visited. For private houses, I would suggest a couple of hours when visitors would be welcome, or alternately, a tour or tours at specific times.
The process of becoming part of the scheme is straightforward: you register on the Heritage Days website, specifying what you plan to offer. The visit has to be free, but if (for example) you wished to provide tea and coffee etc, you could charge for that.
You will find all the details here
org.uk/ and then click “Can I take part?”