Les Whitaker, 75, got back from a month-long break in India to find a massive structure had been built up to the boundary of his property in Shrewsbury, Shrops.
The grandfather-of-seven said he was completely unaware of the plans for the major extension to the neighbouring house, including a two storey storage building which now towers above his back fence.
Despite Shropshire Council approving the planning permission last September for neighbour Glyn Jones, involving significant changes to the adjacent house, Les claims to have been completely in the dark about the development.
Feeling bypassed, Les insists there was no word from the council about the ambitious project at Field House, or he would have lodged an objection.
The family man, who shares his home with his wife Heather, 75, is annoyed as the unsightly new construction not only blocks light but also stirs fears of decreasing his property's value.
The retired design and advertising agency manager expressed his dismay: "I came back from a month's holiday in India, and there it was.
"It's a massive building, it's bigger than my bungalow.
"I had no knowledge about what was happening at all.
"I contacted the council and they said they don't have to write to neighbours.
"Apparently around Covid time, they changed their policy which basically says they don't need to inform residents of these type of applications."
In Tracy Darke's report, the assistant director of economy and place claimed "the proposed development will not result in any detrimental impact from causing an overbearing impact, loss of light or loss of privacy".
However, Les contested this: "It was all signed off as not impacting any neighbours, well I beg to differ.
"It's an eyesore and also blocks out some of our light. It has probably impacted the valuation of our house and we've had the discussion about whether to move house or not now.
"Its just a sad state of affairs really.
"I believe it's a garage and storage facility but the application said something about accommodation as well, so we're not too sure what he's going to use it for.
"I don't know exactly how big it is either but it's a two storey building with a three car garage.
"It sounds like the only way you can be notified of these things is to sign up to an alert for developments in your area.
"Other than that the council can just pretty much do as they please, and I want other people to be aware of that.
"It has had a big impact on us and we're not best pleased about it".
A spokesman for Shropshire Council outlined the process, explaining: "The application was publicised in accordance with the legal requirements and Shropshire Council's policy by a site notice, and the application was also available to view in full on the planning portal on the council's website."
He urged locals to make use of their services, saying: "We encourage residents to sign up to our planning online service where they can register their interest in receiving updates about applications for planning permission in their area."
Describing the benefits of the system, he added: "The system allows residents to set an area of interest and to track applications of interest."
It has been noted that Glyn Jones has been approached to give his point of view on the matter.