Kevin O’Connor checks on a 1970s ranch, gaining an attached ADU for the homeowners’ parents. Outside, general contractor Kevin Smith shows him the new hidden driveway for the ADU. Other exterior changes include a new front porch, green siding, and white window trim on the entire building, updated electrical service from a different location, and a buried propane gas tank. A big deck for the backyard is soon to come.
Inside, insulation pro Jesus Barroso explains the different insulation values in open and closed-cell spray foams and why he used one of each in the corner walls of the unconditioned garage. General contractor Jared Ruggieri shows Kevin the required fire-rated wall assembly and mineral wool insulation between the main house and ADU, as well as a fire damper in the shared HVAC ductwork.
Down in the mechanical room, Richard Trethewey and Bob Connolly review the new hydro-air system for the ADU, which runs off the new gas boiler that serves both units. Then they look at a whole-house water filtration system.
In the basement where the new ADU foundation meets the old house foundation, Sean Hayward shows Kevin how he seals the “cold joint” – where new concrete meets old concrete – with injected polyurethane foam to prevent water infiltration.
Finally, in Dorchester, Kevin and Tom Silva meet homeowners Cara and Paul and their son Tom, who want to transform their attic into an ADU. Their general contractor, Gareth Barr, transforms their cluttered attic into a compact ADU with a private entrance, an efficient kitchen and laundry, a heated-floor bath, clever storage, and a bright new living area with hidden mechanicals.
Original Air Date: May 14, 2026, Season 47; Ep. 24 23:42
Products and Resources
- Contractors:
LDS Construction
Barr Construction - Insulation: Advanced Green Insulation
- Plumbing: RGC Plumbing
- Water treatment materials: Steadypure Water Treatment
- Waterproofing materials: Drycrete Waterproofing
