@Fitzroy has a good point, the hassle of living with a listed building depends totally on the conservation officer in your area. They can be realistic or a complete wally. Make an enemy of them at your peril. The rules state you can make minor repairs, but that’s a matter of interpretation. One persons minor is another major. Anything other than ‘minor’ needs approval. Without it you it’s a criminal offence with you potentially having to undo the work and reinstate to their specifications a large fine and if there’s ever room in prison a remote chance of a custodian sentence.
So let’s say you want to repair some timber, you should approach the local conservation officer to find out if they consider it minor. Well, they will have to visit the site to determine, they will then officially tell you what they think, which you should prepare yourself for, is that they do indeed deem it to require a full listed building consent. Why wouldn’t they? Well because they are employed to do this type of work, if nothing needs full LBC they need fewer of them! Self preservation of your job comes into play! Now, that all costs money, it’s not free, and every visit is a further drain on your finances.
So they determined you need full LBC, so you have to prepare a full work specification, detailing what timber will be used, species, possibly whether it’s air or force seasoned, what joints you will use, what glues, fillers and then treatment of the timber afterwards to protect it (some work may need be deemed requiring a specialist approved heritage tradesperson or what ever they call them these days eg lime mortar pointing can trigger this). All of which they have total control of whether they will approve or not. So there is another bill. Next they will want to inspect the work. Potentially at different stages of it being done to make sure their happy that your in compliance and it’s being done to a standard they approve of. Each visit they can pass or fail and you have to comply with their every whim. Each visit is a further cost.
So, what would have cost you say £20 to do in a modern house you can be staring down a bill of £1,000. The joys of owning a listed building!