Sispal purchased the property before it was built, putting down a £500 reservation fee before securing a mortgage for the £450,000 asking price.
But the problems started immediately, he said.
“From the moment I moved in there were signs of this property’s windows leaking quite significantly to the point where the water was going down the stairs. I did report this and they said this had already been addressed.
“For 10 months, I was left with water pooling in and dripping all the way through the frames, all the way along to my bed, and at 05:00 when there was a thunderstorm having to put towels down and trying to stop the water going down to the rooms below.
“My floorboards are lifting and bowing and they will never be the same again.”
Sispal said his main problem was the cold – with heat escaping quickly from the house.
“Through the day when I’m working in my office, the floor is cold as if it’s wet. It’s freezing cold in the whole house.
“Ultimately, because my health worsened, I had to leave the property over winter and I’ve had to do that two years in a row and stay with my parents while still being on hook to pay all the bills, council tax and mortgage.”
An Avant Homes spokesperson said the company had replaced the Velux windows in their entirety following multiple repairs.
They said: “We undertook repairs of the Velux window on a number of occasions, but none of them were to Mr Sispal’s satisfaction.”
The spokesperson said the company was liaising with Sispal and the NHBC to resolve issues relating to the top floor bedroom and garage ceiling.
“We are committed to resolving the snagging issues identified by the NHBC and have been actively liaising with Mr Sispal to grant us access to his home to undertake the works required.
“As yet, he has not agreed any access dates with us but once they are established we will be able to enter the property and rectify them.”
In response to a roof leak Sispal had in the home, an Avant spokesperson said the company had attended within 48 hours of being made aware.
They said: “The NHBC has investigated the roof leak and found nothing materially wrong with the ground floor extension to cause the leak.”
A spokesperson from the NHBC said the organisation had assisted Sispal under its resolution service on three occasions.
They said: “Some valid works have been completed by the builder. The builder is ready to carry out the remaining necessary works identified and has requested dates from Mr Sispal to agree when he will allow access to his home to undertake them.
“We remain committed to ensuring Mr Sispal’s concerns are resolved in line with the building regulations and our industry-leading standards.”