The fortieth season begins with Kevin outside The Breakers in Newport, Rhode Island – a magnificent mansion once owned by the Vanderbilt family. Tommy picks him up in the truck and they drive across the bridge to Jamestown to this season’s first project – a 1920s bungalow.

Old shingles with asbestos are removed and a new foundation is formed in a factory. Kevin tours Jamestown.

Jeff shows Kevin how he's framing the net zero house, and Richard demonstrates heat loss and gain to design a balanced HVAC system.

New apprentices join the team in Rhode Island as the roof goes up. The homeowners visit a cabinet showroom to finalize their plans. The house gets sheathed. It's the finish line at Judith's house in Charleston. Kevin and Tom take the grand tour.

Insulation is crucial to a net zero house. Kevin finds Jeff and the apprentices starting the work. Dana shops for efficient yet decorative lighting. Tom and Jeff work with the apprentices to build false rafter tails and then they install them.

Roof insulation is next step at the net zero house. Richard tours the basement of The Breakers in Newport. Kevin meets Congressman Norcross at the house, who is also an electrician. Apprentices install and flash windows.

The electrician installs a load center at the Idea House. Tom teaches the apprentices the correct application of cedar roof shingles. Kevin and Jeff add insulation to the basement. Tom shows Mary how to block behind walls with future cabinets and wall fixtures. A pre-cut post and beam barn gets raised.

Sealing the home against air leaks; reviewing the pre-drywall checklist; landscape plan; fabricating pieces for porch columns and rails; shingles are applied as the last layer of the exterior wall system.

Reviewing design samples; heating pump; applying stone veneer; installing a wall-hung toilet tank; building a vanity.

The difference between blueboard and drywall; sizing a solar array; installing a wood ceiling; installing a generator; a boat building school.

Sod farm; HVAC installation; adding a gas fireplace to the living room; attaching screens to the side porch; digging a well.

Induction cooking; installing solar panels on the barn roof; installing a unique lattice; ERV demonstration; landscaping and hardscaping.

The net zero house is complete; touring the yard, barn and upstairs; checking out the main floor; reviewing mechanicals.

Renovation plans for a 1957 mid-century modern house in need of a total overhaul; demolition begins.

Asbestos and tree removal; a visit to the first "This Old House" project in Dorchester, Mass.

Laying a sill on a new foundation; scoping the sewer; starting a design plan to create a sleek, modern space.

Pouring a buttress; revisiting the 2001 Manchester by the Sea project; solving a ductwork problem; installing a PVC trim overhang.

In-counter outlets; former apprentice Nathan Gilbert; framing a skylight.

Selecting patio pavers; installing a skylight in the bathroom; repairing the foundation.

Calculating the risers for a set of stairs; insulating the foundation; installing radiant heat; revisiting an old project.

Installing rafters for a cantilevered roof; solving a venting problem for the kitchen sink; fixing AC ductwork; installing snow cleats on the roof.

Rebuilding a century-old puddingstone wall; revisiting the 2005 Cambridge modern project; installing trimless LED recessed lights; installing large tanks under the driveway to curtail rainwater runoff.

Manufacturing plate glass and windows; cold weather painting; installing radiant heat under the driveway while the patio is installed out front.

Laying large-format tile in the living room; visiting the 20th-anniversary project in Key West, Fla.; installing a hanging retro fireplace and modern kitchen cabinets.

Installing closet systems, modern baseboards and a linear wall drain in the master shower; selecting door hardware; installing floating bathroom vanities.