|The jetty seen on this house is created by projecting timber floor beams at first floor level.|
Traditionally, jettying was the art of creating overhangs as seen in timber-framed houses of the 14th to 17th centuries. The jetty (or jettie or jutty; derr. French ‘jeter’ to throw) refers to situations in which the upper floor overhangs the floor below by as much as 1,200mm (although usually around 400mm). If a house comprised two storeys above ground, the second storey would often overhang by as much as the one below.
 Reasons to jetty
Although the exact reason for jettying is not known, the most commonly-cited explanation is the need to provide extra space. While this is plausible – especially in the confined conditions of a medieval town – many of these buildings were in rural areas which did not have the same spatial constraints. In any case, the space provided by a modest jetty may not have yielded significant usable space.
Other possible reasons include:
- Fashion: If jettying originally started in towns, rural builders may simply have been keen to be seen ‘keeping up with the times’ and offering the latest building techniques.
- Structural 1: A heavy item of furniture in the middle of an upper floor room could, over time, cause sagging of the floor joists. By placing such heavy items in or close to the jetty – and therefore directly above or closer to the point where the joists bear on the wall below – much of the weight of the item is directed to the wall below and could also straddle over the wall.
- Structural 2: In a house with a two-storey central hall, jettying would require timbers only one-storey high, as opposed to timbers that extended right up to the eaves.
- Social status: Jettying was an added expense to the cost of building so having a jetty may have been a way of expressing the wealth of the householder.
- Weathering: These buildings seldom had eaves' gutters and downpipes so much of the water running-off the roof would flow down the walls. The inclusion of a jetty may simply have been a precaution against damp, protecting the lower floor from run-off.
 Related articles on Designing Buildings Wiki
- Advantages and disadvantages of timber frame buildings.
- Balloon framing.
- Delivering sustainable low energy housing with softwood timber frame.
- Sacrificial timber.
- Skeleton frame.
- Testing timber.
- Timber framed buildings and fire.
- Timber post and beam construction.
- Timber preservation.
- Types of frame.
- Types of timber.
A ‘Methodology for Moisture Investigations in Traditional Buildings ‘ has been agreed between RICS, Historic England and the service provider PCA, a trade body, which should help raise professional standards and consumer confidence.
The Templar Hotel on Vicar Lane has been listed at Grade II by the Department for Digital, Culture, Media and Sport on the advice of Historic England.
Government has announced a new Champion for Modern Methods of Construction as part of the government’s drive to make the UK the global leader in housing standards.
Planning is about so much more than the number of applications approved and the speed of processing them so the RTPI is commissioning research aimed at producing a toolkit that can demonstrate a wider range of outcomes.
London blogger The Gentle Author has been photographing the changing face of London, focusing on what is known as ‘facadism’, the practice of destroying everything apart from the front wall and constructing a new building behind it.
Urgent repairs have been ordered to save one of the country’s most endangered buildings from dilapidation while Great Yarmouth Borough Council seeks an investor.
SNH has published new guidance on how best to fit pollinators into urban design and construction with a series of easy steps to suit all project budgets and sizes.
Applications are invited for the Sustainability Scholarship 2020, with successful applicants to receive £3000, support and mentoring from experts, and closing 29 November.
It was hoped the 1.4 mile (2.3km) Victorian Queensbury Tunnel could be used by cyclists travelling between Bradford and Halifax, but plans have been threatened.
Completing works that widened public access to the hidden architectural spaces and collections of Durham Cathedral showcases exceptional project management.
This month HSE is carrying out its latest construction inspection initiative with a focus in particular on measures in place to protect workers from occupational lung disease caused by asbestos, silica, wood and other dusts when carrying out common construction tasks.