Timber Frame

For Timber-Frame Construction, Look for Reclaimed Materials

Bird's-Eye View

The big-boned house

Compared to stick framing, timber framing uses larger pieces of wood, with wider spacing between members. In a traditional timber frame, the vertical posts are joined to the horizontal beams with mortise-and-tenon joints and wooden pegs. The structural network of timbers in a wall or truss that makes up one cross-sectional part of a timber frame is called a bent.

Whether timber framing is green depends on the philosophy of the builder, where the materials originated, the logging practices used to procure the materials, and the durability of the finished home.

See below for:

Key Materials

This big frame can accommodate a variety of wood species

Timber frames can be built from eastern white pine, long-leaf pine, cypress, Douglas fir, northern red oak, white oak, and many other species. Some timber framers specialize in reusing beams from demolished buildings to construct a new house.

The size of the timbers depends upon structural and aesthetic requirements, but 8x8 and 10x10 are typical sizes.

Design Notes

People care for attractive homes

Reusing old timber frames isn't just resource efficient. Old hand-hewn and rough-sawn structures have an aesthetic that appeals to a wide range of people, whether or not they prefer modern or traditional architecture. Part of the value is that attractive, timeless buildings are typically better cared for than mediocre ones. Some people are lucky enough to find old barns that can be shored up and refitted right where they stand. Often, however, a frame will be stripped, dismantled, and stored until it can be recycled into the skeleton of a new structure. Removing historical structures from their original sites brings up some concerns, but many of the barns, mills, and warehouses that are salvaged would be destined to fall on their own if they were not claimed by well-meaning builders.

New frames have their benefits. A custom-built timber frame will offer more design flexibility. In fact, new frames have unlimited potential for shapes and textures. Starting from scratch might also make it easier to address efficient space planning and ideal sun exposure. The open spaces and the warm, strong look of exposed timbers are likely the main attractions in these homes.

Builder Tips

A timber-frame roof on conventional walls

Clients sometimes request an exposed timber-frame roof for a great room in a conventionally framed house. To keep costs down, timber-framed roof trusses can be placed on conventionally framed walls. Such roofs typically have purlins that are 4 feet on center; the tongue-and-groove (T&G) ceiling boards are installed on top of the purlins perpendicular to the ridge. Several layers of rigid foam insulation go on top of the T&G boards, followed by eave-to-ridge 2x4s for a vent channel and oriented strand board or plywood roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. .

The Code

You must check with your local code official

Currently there are no prescriptive design guidelines in the IRCInternational Residential Code. The one- and two-family dwelling model building code copyrighted by the International Code Council. The IRC is meant to be a stand-alone code compatible with the three national building codes—the Building Officials and Code Administrators (BOCA) National code, the Southern Building Code Congress International (SBCCI) code and the International Conference of Building Officials (ICBO) code. for timber-frame construction, so a local code official may require that an engineer or architect sign off on the design. Timber framers typically have relationships with local architects and engineers who are familiar with timber frame construction and can help with design and code-approval issues. Some timber framers have these services available in-house.


Some builders use both stick and timber framing in the same house. For instance, the building's main public space, which is probably larger and more open, could be timber-framed, while the surrounding smaller bedrooms could be stick-framed. These hybrids combine some benefits of each approach — the speed and resource conservation of modern building materials and the beauty of traditional timber-frame construction in high-visibility areas.


LEEDLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify. -H MR2.2 (Materials & Resources) offers points for environmentally preferable wall framing, including FSCNonprofit organization that promotes forestry practices that are sustainable from environmental and social standpoints; FSC certification on a wood product is an indicator that the wood came from a well-managed forest. and salvaged lumber.

NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. Under Chapter 6, "Resource Efficiency": up to 4 points for use of certified wood products (under one of four cited systems) in at least two major building systems (e.g., floor, wall, roof) (606.2).


A time-honored building method

Timber framing, also known as post-and-beam construction, is an ancient building method that is more expensive than conventional stick framing. Still, it is appealing on several levels. A frame of recycled timbers covered with SIPs can make a great-looking house that's also green.


Time-tested joinery

Modern building codes may require the use of some metal connectors in a timber frame, but the construction essentially relies on traditional methods of joinery, such as dovetail and mortise-and-tenon joints, that are inherently strong and stable. Houses can be designed so that some or most of the frame is exposed, making interiors warm and inviting.

Advantages of an open floor plan without bearing partitions
It isn't just the look of attractive timbers that can make a space more comfortable. With smart window placement, the openness of a typical timber frame can let in plenty of sunlight, giving great opportunities for daylightingUse of sunlight for daytime lighting needs. Daylighting strategies include solar orientation of windows as well as the use of skylights, clerestory windows, solar tubes, reflective surfaces, and interior glazing to allow light to move through a structure. and passive solar heating.

Large timbers allow generous clear-spans without the need for many, if any, interior bearing walls. This makes interior spaces easier to rearrange as the needs of the building’s occupants change.

Timber frames work well with SIPs
Another design option, the use of structural insulated panels (SIPs) as exterior walls, creates a tight, well-insulated building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials. and gives timber-frame buildings a performance edge over standard stick-frame homes. Using SIPs to wrap the timber frame also places the frame within the conditioned spaceInsulated, air-sealed part of a building that is actively heated and/or cooled for occupant comfort. , stabilizing it from the effects of temperature and humidity swings. Straw bales, cob, and leichtlehm are some less conventional wall materials that work well if detailed properly. Factors to consider when choosing infill materials include local availability, desired wall thickness (straw bales produce very thick walls), and the availability of skilled labor.

Big timbers come from big trees, so choose wisely
Unfortunately, timber framing uses a resource that is increasingly precious. Large, old-growth trees understandably make the most desirable frames, but this is exactly the lumber that can’t be harvested sustainably. There are at least three other options:

  • Reclaimed timbers. Abandoned factories and industrial buildings as well as old barns yield large, high-quality timbers that can be refashioned into new houses. However, reclaimed wood also is a finite resource. Eventually there will be no more old buildings to dismantle, and prices for the best grades of this wood tend to be high. Mills and factories were often built with Douglas fir and southern yellow pine brought in by rail. Barns were more often made from whatever types of trees were growing nearby. In both cases, reclaimed timbers may have surface staining or defects as well as signs of old joinery.
  • Standing dead. Large trees that died before they could be cut down are another source of timber. So-called forest-salvaged timber has a lower moisture content than newly cut and milled lumber, minimizing checking and dimensional changes once the frame is complete.
  • Buy local or buy certified. Specifying wood that has been certified by the Forest Stewardship Council(FSC) Nonprofit organization that promotes forestry practices that are sustainable from environmental and social standpoints; FSC certification on a wood product is an indicator that the wood came from a well-managed forest. (FSCNonprofit organization that promotes forestry practices that are sustainable from environmental and social standpoints; FSC certification on a wood product is an indicator that the wood came from a well-managed forest.) ensures that the wood was responsibly harvested. Or, where lumber resources are extensive, buy locally cut logs, which both reduces transportation costs and supports the local economy. Although the wood may not be FSCForest Stewardship Council. An independent, nonprofit organization that promotes responsible forest management through the use of a third-party certification process. FSC certification includes a chain-of-custody requirement that tracks sustainability of wood products from growth to end use. certified, a local sawmill is likely to know when and how the trees were harvested.

    Timber Frame Business Council.

    Timber Framers Guild

    "Residential Open Building"

    Image Credits:

    1. Chuck Bickford/Fine Homebuilding #166
    2. Roe A. Osborn/Fine Homebuilding #180
    Tags: , , ,
    Register for a free account and join the conversation

    Get a free account and join the conversation!
    Become a GBA PRO!