Nick Knowles and the team head to Barnstaple in Devon to help Jan and Lucy.
In the first episode of the series, Jan and Lucy have five wonderful kids: Hadley, Kenneth and triplet daughters Lola, Daisy and Amber.
Complications before the triplets were born have left two of them living with nephrotic syndrome, a disease that causes kidney failure and requires them to have 70 hours of dialysis each week.
The nearest hospital that offers the service they need is a four-hour round trip away, and with the girls scheduled for treatment on different days, it means Jan and Lucy are constantly in the car driving to and from the hospital.
As a result, family life is suffering. But help is on hand as the DIY SOS team along with designer Laurence Llewelyn Bowen and hundreds of local volunteers arrive to extend the family home to create a home dialysis centre, enabling the girls to be treated where they live and the whole family to settle into a healthy and happier routine.
DIY SOS returns Monday 15 February at 9pm on BBC One.