Here at Huff Puff House, we design and manufacture a kit that makes it simpler for our customers to build their own home.
Every now and again a building design really catches your eye and imagination – and the Huff Puff House is as functional as it is good looking. It’s an offering that puts a beautiful, affordable, highly insulated and environmentally-friendly building within the reach of our self-build customers.
The Huff Puff House uses straw as its main form of insulation, which is a sustainable, local and cheaply available material. The basic structure is a simple ‘cruck frame’ design, which leaves the vaulted interior totally free so it can be divided as and how our customers wish.
Cruck frames have a long history in the UK and our modern take on the design allows our customers to choose any length and internal widths from 5m-9m, then come up with all sorts of internal configurations to best fit your needs. For example, two generous floors can maximise floor space, or a mezzanine approach can allow for a floor to roof ground floor where desired. Alternatively, the entire internal space can be left open at full height. Height can also be varied, depending on requirements.
The crucks themselves sit upon a plinth wall on each side and are made from two curved timber I-joists. Each cruck is light enough to raise into position using people rather than machines, and once these are temporarily secured, straw bales are prepared and loaded between each one, all the way up to the ridge. We are also working on full height crucks and a variation that uses recycled newspaper insulation instead of straw. (see our materials section).
Created by the engineer and inventor Brian Waite, the cross section of the Huff Puff House is very similar to the medieval “cruck” frame shape, but made of deep, curved, composite wooden “I” beams, which serve as both rafters and studding, set onto a plinth wall or foundation of local materials. The straw bales are sandwiched between these beams, which are like “ribs”, that continue for whatever length of building is required – at one bale spacing. Paired together they form a bowed “A” frame that has the inherent strength of the “A” frame but contains more volume so will easily accommodate a generous first floor for all or part of the length of the building – the interior is totally free of structural restrictions. The gentle curved shape allows the straw bales to rise, seamlessly, all the way up to the ridge thereby insulating the whole building.
The inside and outside is rendered with a breathable (vapour permeable) lime plaster and, after allowing a ventilation space, the outside is then battened and tiled. The whole structure can either be set on a plinth wall of brick or stone of the height required – well away from flooding – or upon pier foundations, in combination with a timber floor.
The wood frame configuration gives the building a more substantial structure with every bale individually held, thereby eliminating any possibility of settlement. It has a spectacular vaulted interior that leaves the owner an uncluttered space in which to use their own way.
Another aim of this design is to reduce the moisture levels within the bales in the UK climate; the design for the Huff Puff house allows the roof tiles to completely cover the bales and the idea is not only their protection but to exploit the natural stack effect, created by different pressures at different heights, to draw air under the tiles and over the exterior of the lime-rendered bales.