Oak Frame: Design Masterclass

ABOVE: New oak frame uses reclaimed materials to create an authentic ready-aged effect This incredible oak frame house in East Sussex was built by Border Oak, who has developed a cladded panel system, WrightWall, that acts as a breathable insulation solution for post and beam oak frames. Made of natural, sustainable materials, WrightWall is thermally efficient, possesses a low U-value, is quick to install and allows the gentle natural migration of water vapour through the building.

Natural, beautiful, strong and durable, oak has been used to build homes in the UK for centuries and still remains popular today, especially amongst those designing and building a home for themselves.

Until the 17th century, oak framing was the principal building system in England and Wales, and each region developed its own framing traditions based on the availability of oak and other materials. This gave rise to some of the most charming and characterful houses to be found anywhere in the world.

Anyone looking to create an ‘authentic’ vernacular-style oak frame home should research these local traditions and work with a designer and builder who can replicate the frame, materials and detail convincingly.

Yet, design has not stood still, and a growing number of oak frame homes built today are contemporary in style, combining traditional framing techniques with modern forms, large areas of glazing, and modern cladding and roofing systems, including metal and sedum-planted roofs.

ABOVE and BELOW: Traditional construction meets contemporary design - Oak is fast becoming a favoured material in cutting-edge house design, as these homes designed by Roderick James Architects (with frames by Carpenter Oak) bear testament. This new Wiltshire home (ABOVE) was built in a ‘Florida’ style, with low-pitched stainless-steel roofs and painted weatherboarding; Braced with a complex web of steel cables, this curved contemporary ‘tree house’ in Devon (BELOW), is actually a post and beam Douglas fir frame – a more cost-effective material – but appears to be a contemporary take on oak; its large sliding doors face into the tree canopy. Due to its inherent open plan characteristics, oak is the perfect material for creating contemporary interior schemes.

Oak Construction

The essential principles of oak frame construction have changed very little over the centuries — with mortise and tenon joints used to form frames from green oak, secured with seasoned oak pegs. One feature that has evolved considerably, however, is the way oak homes are insulated.

Whilst it is still possible to build a traditional half-timbered home with the skeletal oak frame visible both inside and out – with the voids infilled with high-performance insulation and gasket seals – it is becoming more complicated to do so, especially across an entire house. (Often it is necessary to use trade-offs against additional insulation elsewhere in the building.)

To improve energy efficiency, some frames are insulated between and around the frame, allowing the creation of a continuous and airtight building envelope that has no studs running inside to out, forming a cold bridge. Building this way, the insulation panels and airtightness are far less affected by the natural movement of the frame as it dries out and shrinks in the first few years.

With an externally insulated frame, the structural elements remain visible from the inside only. If you want the oak frame to be visible externally, strips of oak can be fixed to the outside of the building envelope.

ABOVE and BELOW: Exteriors clad in a variety of materials - This Roderick James-designed contemporary oak frame self-build in Oxfordshire (ABOVE) is partly clad in reclaimed local Horton stone and some horizontal European redwood boarding, which beautifully complement the oak frame from Carpenter Oak and its green roof; This Oakwrights self-build (BELOW) is clad in flint and brickwork. (Read more about this self-build).

External Walling and Cladding

As the oak frame carries the load of the building, the external walls work primarily as an insulated weather screen. The majority of new oak frame homes have an external building envelope of timber frame or structural insulated panels (SIPs). Some systems are a hybrid combining a simple post and beam oak frame structure with a structural timber frame or SIPs walls — reducing the amount of oak required and therefore the cost.

Oak frames have also been combined with insulated blockwork walls, insulated concrete formwork (ICF), and various organic walling materials such as straw bales, rammed earth, cob or hemp/lime.

The external cladding will depend on the walling system used. In all instances the masonry plinth will be visible, in stone or brick, and above this the walls may be clad in a single material, or different materials used for the ground and first floor — or possibly for different sections of the building, giving the impression that it has evolved over time.

Options include horizontal timber boarding, either in painted softwood, or in oak or a hardwood, left to weather naturally. Render applied over insulation is a popular choice. Where external feature timbers are applied to the exterior, these are usually infilled using render.

In areas where clay was abundant, and therefore bricks were cheap, oak frame homes sometimes had panels infilled with brickwork, often laid in decorative patterns such as herringbone bond. In stone areas, infill panels may be of local limestone, sandstone, chalkblock or flint.

ABOVE: Period vernacular extension with visible oak frame internally - This oak frame extension was designed by English Oak Buildings (01225 789978) to be sympathetic to the original historic house, so is clad completely in stone with a thatched roof. Inside, however, the oak frame takes centre stage.

More Advice on Oak Frame:

• Oak Frame: Design Solutions
• Oak Frame: Frame Types
• Oak Frame: Experts' Views

Oak Frame Self-Builds:

• An Oak Framed Self Build in Oxfordshire
• A Three Bedroom Oak Framed Home
• An Oak Frame Cottage Built for Under £300,000