Speaking to the owners of the neighbouring properties is recommended. If you are still unsure, you may need to check the original deeds to the property. Generally the rule is that you are responsible for the fence at the right hand side of your property.
Greenford is a significant suburb within the London Borough of Ealing, traditionally part of the county of Middlesex in west Greater London. The town is near many other larger London parts like Southall and Northolt, with a population close to 50,000. For any upgrades you are looking for to your property soon, be sure you only use vetted and reliable contractors for top level value for money for your house.