Leasehold title plan and side return extension

Hello

We own a leasehold property and have a share of freehold.  The lease was registered in 2009 and includes a title plan. The plan correctly shows the demised land edged in red (a ground floor maisonette flat and garden plus an area at the front of the property). A previous owner of the maisonette built a side return extension to the kitchen. This was done in the garden already forming part of the demised land. Are we legally required to update the title plan to show the side return? If so, would this need to be filed at Land Registry and which fees would apply?

Thank you

Hello Catherine - HM Land Registry title plan shows the extent of the land in the title, not the structures built within that extent.  So, if the kitchen extension is within the land in the title then you do not need to take any action.