Drive from the Downs towards the town centre and the housing tells you most of what you need to know. There are 1930s semis with original cavity walls, Victorian terraces tucked off West Street, and plenty of houses thrown up after the war when nobody gave heat loss a second thought. I’ve written about this town’s rental market for a long time, and that mix is exactly why so many owners now go looking for letting agents in Dunstable for EPC advice before a tenancy comes up for renewal. The rules have changed, and they’ve changed in one direction only.…