I have a freehold property for which I pay £17 a year chief rent I wish to extend the property do I need to obtain permission from the chief rent collector.
Thanks.

You really should specify WHERE you are from. I'm assuming since you used a pound symbol you are from the UK, but there are other areas using the pound. What is "chief rent"? Define what you mean by extend the property?

You really should specify WHERE you are from. I'm assuming since you used a pound symbol you are from the UK, but there are other areas using the pound. What is "chief rent"? Define what you mean by extend the property?
Iam from uk chief rent is the rent you pay for the land your property is built on and also extending the property means building extra rooms in your property.

Ahhh, OK. Well I think you need to contact someone familiar with UK laws in this area. In the US, property is the land not any buildings on it. It is rare that someone owns the buildings but not the land. Its generally held that any improvements to the property are part of the property.

Now I would strongly suspect, then, that if you are renting the land, but own the buildings, that you would have to get approval from the land owner to make any changes.