Work has commenced on the extension to the front of the house of our next-door neighbour. (Both our houses are semi-detached). Yesterday, I arrived from work to find the blocks erected on the foundations. Using the paint mark on front of both houses as guideline, it could be noticed that the boundary of the extension has stretched into our side by 70mm / 3 inches. This morning, the front of both houses have been measured, and the result was: Next-door neighbour: 5790mm and our side: 5720mm. This proves my observation that "3 inches from our side had been taken up by the blocks".
The neighbour had given us copies of the plan (though out of date, as modificatoins had been made to the design of the extension) which clearly showed the boundary of the front extension would be within the next-door neighabour's land.
What action should we take? Inform the Planning Office of our Local Authority? We're not keen to go down the legal route, and I'm afraid that our relationship with the neighbours will be affected as a result of the builders erecting blocks "3 inches" too much into our "side" of the land.
Any advice / past experiences of the posters would be vey much appreciated.
allendog