[2009] O8 EG 116, 12 November 2008. Illustrates the importance of defining the exact extent of the demise in a building's lease. A claimant landlord of residential maisonettes under a sublease who wanted to build a further storey above a roof with skylights, applied to the court for declarations that : (1) the roof and airspace above the maisonette were not demised to the defendants; (2) it was entitled to build even though this would block the skylights. The defendant tenants argued that by blocking the skylights some rooms would receive no natural light (although other rooms had windows). It also argued that the roof and airspace were part of the demise and that and any development would be trespass. The case turned very much on the design of the building in question. Held: application refused. The Central London County Court ruled that the skylights were an integral part of the design and structure of the property, so the roof was part of the demise. Further, although there was no express grant of a right to light in the lease, the tenants had a right to light by long use or implied grant. Blocking the skylights would be an infringement of this right to light.