The TOH crew takes on a new project: an 1850s Greek Revival rowhouse in Charlestown, Massachusetts.

A major problem -- exterior walls bowing out from the weight of the roof -- is solved.

Modifying the old chimney for gas fireplace units; framing the third-floor master suite.

Waterproofing the dormer; installing a reclaimed brick veneer on the new kitchen bump-out.

Roughing in ductwork for new direct vent gas fireplace units; Greek Revival details for window trim.

Greek Revival-style front door; kitchen cabinets; wall insert for the master shower; copper roof.

Marble island top; PVC fence; restoring weather-beaten front steps; installing a marble mantel.

New security system, wireless music system and remote-controlled window shades; mechanical room.

The 35th anniversary season continues with a 1966 Colonial in Lexington, Massachusetts; an addition includes a farmer's porch, kitchen, mudroom and access to the garage.

Framing of the front floor platform; new prefab footings are set.

Framing the gable wall; framing the roof; Colonial-style front porches; framing the farmer's porch.

Progress on the back deck; finishing the trim and decking on the corner deck stair.

Landscaping plans for the front yard; connecting the new kitchen to the old great room.

A rough electrical inspection; a hybrid railing system with cedar posts and railing caps; a new kitchen.

Reinforced fiberglass columns to support the porch; a storm window system for the screen porch.

Installing a one-piece covered gutter; updating recessed light fixtures; adding sconces.

Mark Ferrante installs floor tile; Kevin wires an electrical box; Tom squares a doorway.

The progress on the floors and in the kitchen; repurposing a chest of drawers for a sink base.

Installing porcelain in the screen porch; granite for the front walk.

Adding LED ribbon strip lights under the cabinets and in the butler's pantry; mudroom storage.

New plants for the landscaping; radiators; upstairs laundry room; insulated steel garage doors.

Installing new turf; great room entertainment center; heating and cooling decisions.

Reviewing the transformation of the 1966 Garrison Colonial; customizing spaces over the garage.

Partnering with Homes for Our Troops to build a house for an Army veteran and his family.

An ADA-compliant threshold in the shower; an automatic door opener; the benefits of the hybrid-style faucet.

Roger, Tom and Norm build a greenhouse; locals help out at the DeWitt project; a rustic table.

A woman makes changes to her childhood home to accommodate her family.

The new foundation is poured as the house is readied for demolition; mold is found in the basement.

Installing a beam to support a new opening in the kitchen; selecting finishes; tackling the front porch.

Building a new floor; hunting for a clawfoot tub; leveling the front porch; building the roof.

The basics of framing a deck; taking down an old chimney; a custom tile floor.

Framing a wall in the master bedroom; building a drain stack for the master bath; laying decking.

A sliding barn-type door for the new pantry; restoring a flower garden; installing new columns.

Self-sealing membrane and flashing; a thick plastic vapor barrier to prevent mold growth.

Foam shower seat; connecting steel piping; installing replacement windows.

Pre-painted shingles; installing a granite base for a wood stove; trimming windows.

Trimming rough interior columns; making a stained-glass window; installing stair treads.

Installing an old door; a stone wall is installed in pre-made sections; twin built-in beds.

Preventative tree work; tiling; stripping the newel post; the apprentices graduate after 10 weeks.

Laying composite decking; exterior brackets; installing quartz countertops; making a new front walk.

The house in Newton is nearly finished; installing a final detail on the stove.

Wrapping up the Generation Next house; a tour of the renovated house with the homeowners.

A brick 1840s "single house" and a multigenerational 1890s home in South Carolina.

Demolition begins on the projects; planting options; touring American College of the Building Arts.

An old fireplace houses a new stove; using interior casework with exposed brick; hidden gardens.

Foundation and tree work; restoring the mantel and windows; connecting the old kitchen house.

A dining room table; installing HVAC equipment; touring single houses in downtown Charleston.

Rough plumbing; kitchen design; assessing the front porch; snaking wires through brick.

Restoring old piazza columns; fabricating an iron gate; selecting modern light fixtures.

House colors at Rainbow Row; inspecting termite damage; a timber frame class builds a pergola.

The pergola goes up; smart home; installing kitchen cabinets; a table made out of cypress.

Finishing touches are made to the single house while the custom gate is installed.

The 40th season begins with a 1920s bungalow that will become a larger net-zero house.

Removing shingles that contain asbestos; precast concrete walls; placing foundation wall panels.

Framing the net-zero house; designing a balanced HVAC system; International Builders Show.

The roof goes up; visiting a cabinet showroom to finalize plans; the house gets sheathed.

Insulation begins; decorative lighting; building and installing rafter tails.

Roof insulation; touring the basement; Rep. Donald Norcross visits; installing and flashing windows.

Installing a load center; putting up cedar roof shingles; adding insulation to the basement.

Sealing the home against air leaks; reviewing the pre-drywall checklist; landscape plan.

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

Blueboard and drywall; sizing a solar array; installing a wood ceiling; installing a generator.

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

Induction cooking; installing solar panels on the barn roof; installing a unique lattice.

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

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, Massachusetts.

Laying a sill on a new foundation; scoping the sewer; starting a sleek design plan.

Pouring a buttress; 2001 Manchester by the Sea project; ductwork problem; 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.

Installing rafters for a cantilevered roof; solving a venting problem; fixing AC ductwork.

Rebuilding a century-old puddingstone wall; revisiting the 2005 Cambridge modern project.

Manufacturing plate glass and windows; cold weather painting; installing radiant heat.

Laying large-format tile; installing a hanging retro fireplace and modern kitchen cabinets.

Installing closet systems, modern baseboards and a linear wall drain; selecting door hardware.

Kevin, Tommy and Richard tour the home and review all the special features.