A profoundly deaf couple, whose home was left unsafe by unfinished building work, will see it being transformed by hundreds of volunteers when the latest episode of DIY SOS is broadcast.
Ahmed and Rifat Ali, from Bitterne in Southampton, lost £72,000 on a ground floor extension which was halted and later condemned.
The episode, which reveals technology designed to help the couple run their home, will be on BBC One and iPlayer at 20:00 BST.
DIY SOS designer Gaby Blackman said: "All we hear about in our community is division and that is not what we found. We found a united, kind, warm community all really just trying to help a family in need."
Before work began, Ahmed, speaking through an interpreter, told volunteers: "It's been quite a dark period and I just feel like this is the light at the end of the tunnel."
Rifat said: "I can't believe that you're going to change our house and make it home again. We just can't wait to come back. So thank you from the bottom of our hearts."
Show electrician Billy Byrne said alarms would use different coloured flashing lights to tell the parents which part of the house had a problem, describing the system as "revolutionary".
Stuart Hanlon, whose company donated the technology, said display panels would also show a blue light if one of the children left the taps running.
He said of the house before the work: "I have never seen anything that dangerous. One wrong step and it would have been a very different story."
Furniture maker Radha Sivyer, who redesigned the bedroom shared by the couple's two sons, said: "We're not making things to look pretty for TV. We're actually building real, meaningful, changed homes."
Neighbours said the build had brought the street closer, with a roast dinner for residents at a spiritualist church and a new WhatsApp group.
Electrician Tom, from Portsmouth, said the volunteers, many of whom came from Portsmouth, Gosport and Southampton, had formed "a strong band of brothers" who now help each other find work.
Knowles said that long after people had forgotten who he was, the homes the show had built would "still be looking after people".