A very well preserved Bronze Age roundhouse is under excavation at Must Farm in Cambridgeshire. The house was built on top of a raised timber platform over a prehistoric river channel, and is of a type of settlement known as a crannog. Dating to 1000 - 800 BC, it seems the house collapsed into the river after the platform, and the piles holding it up, caught fire. The survival of this quantity of structural timber is very rare, and is due to the anaerobic conditions of the overlying river mud. Pottery vessels containing food remains have been found, as well as valuable items such as a bronze dagger and spearhead, suggesting that the occupants                                                                                                                                             had to leave in haste and could not retrieve their                                                                                                                                                     belongings.

                Images: Cambridgeshire Archaeological Trust

This little roundhouse is pretty unique as it has been thatched with heather. It is 5m in diameter and based on an excavated building at Deer Park Farms, Co. Antrim. Labelled an 'undifferentiated structure', the wall and roof are one and the same rather than two separate elements as with most reconstructed roundhouses. The wattle wall was built in the traditional way to a suitable height. More hazel rods were then inserted into the weave of the wall and pulled together to form a cone, which was then wattled just like the wall. Bundles of heather were then pushed into the woven roof.
Image: UCD

This house, seen in the background of the above photo is a reconstruction of a Mesolithic roundhouse, the remains of which have been found across Britain and Ireland, and date to around 7,000 - 8,000 BC.
​Image: UCD

The new roundhouse at the Irish National Heritage Park in County Wexford. This looks to be a good strong house, and  an interesting one too, for the double-skinned wattle wall will be filled with crushed sea shells. However, it is odd that the rafters do not rest directly onto the large wall posts, but rest on rather thin-looking wall-plate . A small bird's mouth joint into the base of the rafters to match a similar slope cut onto the top of the wall post, would make for a strong union and provide excellent weight transfer. The taller posts situated inside the house may be somewhat unnecessary, but here too lap joints would've helped to take the load of that thick thatch.

The great majority of recreated roundhouses are thatched in the 'Glamorgan' style, which is composed of successive layers of wheat straw or water reed held down by wooden or steel spars affixed by wooden staples. It is characterised by its thickness and smooth uniform finish typical of cottages in The Vale of Glamorgan, south Wales. Because this style is a 19th Century development of a much earlier form of thatching, its use detracts from the accuracy of these buildings as experimental constructs and produces skewed results.


'Thrust' thatching is the earliest documented form of thatching and is named after the action required for securing the thatch into place. It requires the roof rafters to be entirely weaved with hazel wands, rather than individual wands tied to the outside of the roof at 14 inch intervals, as is common today. Branches of gorse were then inserted into the weave to create a thick under-thatch. A wooden tool called a 'spurtle' or 'spud' was pushed into the gorse to create an opening into which handfuls of straw was thrust. Thatching roundhouses in this way would most likely be more representative of Iron Age practices.



  

Also known as 'jelly-bean' or 'figure-of-eight' roundhouses, conjoined roundhouses are a single structure composed of two circular cells butted up to each other, which sometimes share a connecting doorway. One cell is usually smaller than the other and these may have been used as store-rooms. Such roundhouses were to be found right across Britain and Ireland during the  Iron age. On the island of Great Bernera in the Western Isles, Scotland, conjoined roundhouses were found on Bosta beach dating to the 1st millennium AD. These were semi-subterranean. The image is of the reconstruction at Bosta beach.


The National History Museum, St. Fagans, in Cardiff, Wales, is building its own conjoined roundhouse based on excavations in Bryn Eryr, Anglesey.  The excavated walls were 2.1m thick and made of clay. There is some debate regarding how best to roof such a structure. Some suggest roofing each house individually and merging the thatch where they meet, while others suggest that building a single roof that covers both cells would avoid any awkward unions.

In Ireland and Scotland crannogs were common from the first millenium BC and some continued in use until the 17th century AD. These are artificial islands built in lakes and estuaries that usually held a single roundhouse which could offer sanctuary and safe storage for the family and its livestock. More than 500 have been recorded in Scotland and similar numbers in Ireland.

In some cases an artificial island was made-up using earth and stones, while others were composed of alder piles driven into the lake bed, and braced to form a platform above the water-line. Llangorse Lake crannog in Breconshire, the only known Welsh example, has yielded dates from the 9th century AD for a timber platform and a palisaded enclosure: it seems to have been a residence of the Irish-descended royal house of Brycheiniog.

The Little Woodbury roundhouse, Butser Ancient Farm.

Just before the outbreak of the Second World War, Gerhard Bersu, a German archaeologist who fled the Nazis and came to Britain, undertook excavations at Little Woodbury near Salisbury in Wiltshire, a site identified through aerial photography. Up to this point it was commonly believed that the people of this period lived in simple shelters called 'pit dwellings', little more than a tent erected over a hollow. Bersu opened a large area and noted two concentric rings of post-holes that formed a 15m enclosure that he postulated were the remains of an Iron Age house. 

Butser Ancient Farm is a purpose built archaeological research centre founded by the Council of British Archaeology in 1970 and run for many years by Peter Reynolds. His work, along with David Freeman among others, has been fundamental in enhancing our understanding of Iron Age archaeology, and consequently Iron Age life.

The Little Woodbury roundhouse was substantial and contained four central posts within the main post-ring. These, according to some, could have supported a mezzanine floor, and two large holes in the ground found within the roundhouse could have been footings for a staircase. For this to work the roof would have needed to have been at a steeper angle than as seen on this reconstruction, in order to provide a usable space.