The Walter Segal self build approach to construction is uniquely organised so that anyone who can use basic tools such as a saw, hammer, drill/driver, tape measure, etc. can build a house. There are even one or two cases of single parent mothers, who have had only basic training in woodworking skills, building their own houses. It’s not quite Lego, but probably as close as you can get using standard building materials. This can create large savings in construction costs.
No wet trades are used (like bricklaying and plastering) – skills which are difficult to acquire. It is a stripped down system of construction with a highly minimalist and rationalist approach. It has proved very adaptable in terms of upgrading to high insulation values and handled properly could probably achieve PassivhausSee more on the Passivhaus standard. The PassivHaus Institute has pioneered a standard for low energy buildings. It includes very low energy usage and ways of achieving this. The word is derived from the idea of buildings which are fundamentally low energy and passive solar heated rather than using extra gadgets to heat them. See Passivhaus for the UK branch of the organisation. or Zero carbonbit of a slippery fish. It tends to mean that a building uses no carbon (oil, coal, etc) to heat it (meaning in a 'net' way). It usually ignores the carbon which goes into building it (the embodied energy). See the page on Zero Carbon? standard. However, this can be seen as quite a challenge, as is the case with many types of construction which involve sealing multiple sets of construction joints to achieve air tightnessA measure of how leaky a building is to air. In other words, how draughty it might be. There are now standard fan pressure tests to check how air tight a house is and the Building Regulations have minimum standards for all new houses (L1A – Conservation of fuel and power in new dwellings (England)). A much higher degree of air tightness is covered by the Passivhaus standard.
Though there are many excellent examples of Segal houses in the UK, the development of the system has recently become somewhat moribund because the people involved with it, mainly architects working in the green building movement, are busy with other things. There is also a rather low cultural level of understanding of timber construction in the UK. Hence the slow uptake of prefabricated and flatpack houses. see Timber Culture)
It is a bolt-together, post and beamSubstantial, usually horizontal structural member. form of timber frame construction which relies on using all the materials in their standard sizes, as they are delivered, so there is almost no cutting or waste. The foundations are point blocks of concrete, usually 600 x 600 wide, (depth depending on soil conditions) so less concrete is used than in strip foundations. There is no oversite concrete used so this cuts down on embodied energythe total amount of energy it takes to make a material (or a building). See more on embodied energy. Originally intended to be single storey[for the purposes of part B (fire) of the Approved Documents to the Building Regulations] this includes - (a) any gallery[for the purposes of part B of the Approved Documents] - A raised area or platform around the sides or at the back of a room which provides extra space. if its area is more than half that of the space into which it projects; and (b) a roof, unless it is accessible only for maintenance and repair. construction, it has proved to work well up to three storeys (although this is pushing things a bit and requires a large input by a structural engineer) – see Allerton Park.
Although the system is basically simple and very flexible it still requires that full sets of drawings and structural calculations are supplied to Building Control and these will normally be prepared by an architect or architectural technologist and a structural engineer.
A frequent request on this web site is for construction details of the Segal system and we hope to publish these shortly. Requests on the contact form below will speed this up. You can see the basics of the system on Dominic Stevens web site. Bear in mind that it is a construction system rather than a set of house designs. It is very flexible and you still need to design the house.
As energy standards are tightened up it may well prove impracticable to design in the amount of air tightness necessary to achieve zero carbon or Passivhaus standards although insulation itself should not be a problem. However there are developments afoot to produce kit houses to the new standards. See below.
Check this out if you are interested in a kit house
Recently announced timber kit house from Passivhaus Homes. It looks like they are providing a design service and kit “to full Passivhaus standard (15kWh/m².a) or our PH30 ‘near Passivhaus’ specification to 30kWh/m².a.”
There are a couple of exemplary group housing developments such as Hedgehog Housing Co-op in Brighton at Hog’s Edge and the houses at Walter’s Way in London. (Some Google images here and usually one of Walter himself, though now deceased)
There are also many individual houses which have been built to the same principles. A good example is Ken and Sylvia’s house at Lampeter Velfrey near Whitland in Pembrokshire. Ken runs Water Margins, an aquatic plant nursery and next to the business they have built a single storey house.
The form is almost square in plan and the South elevation has a long glazed sun room which helps with heating the house. The structural timber posts are all 100mm square rather than the 200 x 50 which is more common with the Segal system. You can just make out the 600 x 600 concrete pads which the posts stand on. The outside wall cladding is Minerit and the inside lining is Fermacell. There is 200 mm insulation all round using wood wool and polystyrene. The level of insulation, along with the open plan layout of the rooms, has meant that the central wood burning stove has proved sufficient to heat the whole house without a central heating system.The roof membrane is neoprene.
Some recent improvement work on the house has included a 180 litre thermal store at the rear of the stove to capture spare heat and they are planning to install a thermal solar collector on the roof which will also feed into the store.
An up-and-coming new development is Rural Urban Synthesis Society, a Community Land Trust scheme of 30 new, high quality, sustainable homes in Lewisham, to be based on the Segal system.
There are now quite a lot of examples of Segal buildings being taken down, moved and built elsewhere which show the re-usability of the system.
The Architect and Self Build Housing a study by Adam Roberts, which covers some interesting examples of Segal stuff (starting page 23)
Superhomes"Opening doors to low energy refurbishment" The homes, which achieve at least 60% less CO2Carbon dioxide is a gas which is given off when carbon based materials such as fossil fuels (coal, oil, and natural gas) are burned. It is called a greenhouse gas because it works like the glazing of a greenhouse and causes global warming emissions, have open days. see the Supehomes website hosts a video of recent eco improvements to one of the Segal houses at Walters Way, Lewisham
Walter Segal Trust (web site needing some TLC)
Architype architects were the designers of the Brighton Hedgehog project and are a ground breaking ecological design company! See their ‘Community Self-Build Projects: Hedgehog and Diggers‘ page for the ‘Diggers’ project and ‘Hedgehog’.
Project sheet – various examples
The AJ library has on line drawings from the Lewisham self build scheme (thanks to Ben for posting a comment about this)
See the link below to a Sketchup guide to Segal design kindly provided by Nigel Taptiklis
The Self-build Book: How to Enjoy Designing and Building Your Own Home by Jon Broome, and Brian Richardson. It documents the building of a Segal method timber frame house and also goes into some community self build initiatives. There is very little written about self build timber frame in the UK (unlike say the US where it is usually the starting point).
A number of Building Regulations may be particularly relevant to the Segal method and various Approved Documents cover this including:
- Part A -Structure
- Part B -Fire Safety
- Part C – Site preparation and resistance to contaminants and moisture (England)
- Part E – Resistance to the passage of sound (England)
- Part L1A – Conservation of fuel and power in new dwellings (England)
Note that compartmentationa term used in the Building Regulations to denote fire resistance between two parts of a building (such as a compartment wall or compartment floor) or between one building and another (for instance a party wall), can be achieved using timber frame construction clad in plasterboard or a similar none combustible material. Also sound insulation between party walls is no problem.