Hi Gabel,

There is something in your hypothesis. Most old timber framed buildings and especially cottages that I check out are about 16 - 18 ft wide. The room that I am sitting in right now is 16.5ft wide [of/of] and this is the old medieval measurement called the rod, pole or perch. Heresay has it that this is the length of the shaft between 2 oxen and that this shaft was used to measure and buck trees in the woodland.

The answer to this question must lie in fact based observations and thus a quantitative survey of building widths would establish whether or not a standard unit of building width measurement was employed. Though I have not done this study I have examined records for about 1500 buildings and found that there is a statistical distribution curve of building widths and therefore this would appear to rule out the concept of standard measurements being employed so what then could drive the establishment of building layout dimensions? The answer might lie with the trees themselves in that in most buildings the longest timbers are the tie beams, cross beams and cross sills. Wall plates, girding rails, purlins and long sills are generally composites i.e. scarfed and so do not require the longest timbers. Thus it might make sense for the builder to examine the logs to hand and then optimise building width based on the mix and then as Gabel suggests simply use a string and pegs to layout the footprint of the building. The one place where this practice might be more constrained is when building in a town on a medieval burgage plot of fixed dimensions. I have checked out the design of a building in Farnham, Surrey with Laurie and we found that it was laid out and cross frames spaced using overlapping circles i.e. string & peg.

From experience in my own woodland I know that I can easily prune most trees with the aid of an extending pole saw to about 16 ft. By the time the pole is extended to the range 18 - 22 ft it becomes much more difficult to clean the trunk becuase the pole becomes more vertical and the amount of bend or whip in the pole begins to make sawing difficult and the saw becomes trapped in the kerf as branches droop before they fall. In medieval times commoners were free to take branch wood for faggots (by hook or by crook) from woodlands and probably most landowners would have encouraged this practice since it would have provided them with good clean standing trees thus woodland management practice might play a larger part in building layout than we might currently credit today especially since most people tend to be well divorced from the origins of timber (Home Depot).

This might prove to be an interesting dissertation topic for a bright student to pursue.

Regards

Ken Hume