Starting to model Woodhenge in Google SketchUp

The Story so far
Since I decided to blog this research five years ago, one recurrent theme has been my attempts to understand the largest class of prehistoric buildings Class Ei. [1] This includes Durrington Walls, the Sanctuary, Mount Pleasant, Stonehenge, and Woodhenge, the latter being the most interesting as a result of its non-circular plan.
When, as a result of Tim Darvill’s 1996 paper, [1], I first considered Class Ei buildings, I was initially very sceptical of their scale; I had been working on IA roundhouses where there were clear engineering limits, and these appeared to break my rules for timber structures.   
Against this, I began the compilation of a list of characteristics that indicated they were buildings. While the technical insight that resolved this dilemma probably came from studying the engineering of earlier Longhouses, ultimately, progress comes from breaking down your preconceptions by building models that don’t work. I took the unusual step of actually publishing some the models that had not worked in order to demonstrate why it was necessary to create a more complex solution.
It is harder than you might imagine to deduce from the evidence, rather than simply impose ideas on it.

'...when you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.'
Sherlock Holmes –
The Blanched Soldier, The Case-Book of Sherlock Holmes, Arthur Conan Doyle, 1927

Twelve reasons why Stonehenge was a building

Stonehenge was a building.  That’s it, no mystery. If it was a rectangle this would not be an issue, but British Prehistoric buildings are predominantly circular from this period onward. 
The rings of postholes at Stonehenge [Y, Z, Q, and R holes] are often ignored, or are thought to be redundant stone holes, but it is just one of a group of concentric timber structures known from various periods in British Prehistory.  Like Woodhenge, Durrington Walls, Mount Pleasant, and The Sanctuary, Stonehenge was a large timber building.  This was tentatively recognised by Tim Darvil in 1996, who called them Class Ei structures.[1]  

Stonehenge and the archaeology of the prehistoric roof

Postholes: cult or craft?

Most of the prehistoric archaeological sites of Britain, even Stonehenge, are covered with postholes, and it is my central contention that these posts were primarily the foundations of timber buildings. Further, since building is a rational process, postholes can be understood in terms of how posts were joined together to create roofed space.

Unfortunately, many academics have convinced themselves that some postholes are the product of a mysterious cult, whose rituals involved placing posts in the ground.

Despite considerable and ongoing research in this cult of postholes and their cosmology, the reasons for this strange behaviour are still not entirely clear. However, unlike the anthropomorphic polytheist religions evident elsewhere in Europe, adherents of these rituals, with remarkable prescience, seemed mainly to be acting out key themes from modern anthropology.

Debunking the myth of timber circles

The Myth

In archaeology there is the evidence, and there are the opinions put forward to explain and connect it.

In the highly subjective world of archaeological opinion, it has become widely accepted that the concentric rings of prehistoric postholes, once thought possibly to be buildings, were the freestanding timber equivalents of Neolithic stone circles.

These ‘timber circles’ have become central to modern understanding of ancient landscapes, as realised by Time Team. [1] Recently, Professor Vince Gaffney has even detected a ‘Timber Stonehenge’ [2].

They account for some important archaeological sites including Woodhenge, Durrington Walls, and The Sanctuary, and are even found in the Iron Age.

In 1996, Tim Darvill called these structures Type Ei buildings, [3][above left]. However, once others, particularly Alex Gibson, ventured the opinion they were too large to be roofed, they became ‘Timber Circles’ [4]. Many academics have long since moved off to explore this strange freestanding ‘ritual’ landscape, although, officially, it appears that the jury is still out:

“A timber circle is the foundation of a large wooden structure comprising a series of two or more roughly concentric rings of postholes which once supported substantial timber uprights variously interpreted as stanchions of a roofed building or freestanding posts. Timber circles are generally over 20m in diameter and the individual postholes are typically over 0.5m across.”

English Heritage web site. [5]

Actually, they are not too big, but entirely consistent with the scale other large oak timber roofs, and this can be demonstrated because they were made from trees.