FLOOR TO WALL RATIOS

Builders and architects will often use a rough $/m² figure when arriving at a preliminary estimate of the cost of building a home, making reference to tables of figures published by quantity surveyors or found online.

A typical example of the kind of cost per area table of used in cost estimates. The ‘Low’ figures represent a no-frills, volume-built house with the cheapest finishes and fixtures, and the ‘High’ figures indicate a custom, architect-designed house with high-quality fixtures and finishes.

Something that is not factored into these estimates, however, is the effect of the shape of a house on its cost: in other words, the effect that the floor-area-to-wall-length ratio has on the quantity of various materials required to construct a house of any given floor area.

Take the following simplified examples, which consider only the house in plan view, and assume equal wall heights.

A house that is a 10m x 10m square in plan has a floor area of 100m²:

Likewise, a house that is a 20m x 5m rectangle in plan also has a floor area of 100m²:

But the total length of external wall in the former is 40m, and that in the latter is 50m, representing an increase of 25%. This means that the rectangular house shown above requires 25% more studs, plates and noggings, 25% more interior and exterior cladding, 25% more insulation, 25% more building wrap, and 25% more skirtings and cornices than the square house.

A courtyard house, with narrow internal corridors connecting the two main areas, decreases the ratio even further:

There is also the effect of articulation to consider, i.e. adding ‘ins and outs’ to the exterior wall:

At the other end of the spectrum, the absolute most efficient shape for a building if your only aim is to maximise the floor-to-wall ratio is the perfect circle, but this shape is impractical from both a construction and an interior layout/planning point of view:

So why would anyone build anything other than square? In fact, most modern volume-built homes are essentially square in plan, or at least fatter than they are skinny, with a central corridor serving rooms on either side. This allows developers to maximise the floor area of these homes on their relatively small lots while keeping the cost of constructing the envelope of the house relatively low.

A ‘fat’ plan typical of most volume-built houses.

But there are several advantages to opting for a narrow plan over a square one. Cross-ventilation and the penetration of natural light into rooms are both optimised, and there are more opportunities for northern (or, if you are in the northern hemisphere, southern) exposure; in the extreme scenario, every room can be given northern exposure, with a corridor running the full length of the southern side of the house.

Of course, on most projects the advantages of narrow plans listed above must be weighed against budgetary and site constraints and other considerations, but it doesn’t hurt to at least have floor-to-wall ratio in mind when determining the best plan-form for a house. Construction is a one-time cost, but the utility and amenity of a home are lifelong.

VERNACULAR PICTURES 16: OARS

Just some pictures of oars. Some good colour/pattern ideas in there for buildings!

JAPANESE MINKA X - TWO RIDGE MINKA

After covering several varieties of magari-ya in last week’s post, today I will look at another general minka type, the futamune-zukuri (二棟造り), or ‘two ridge’ minka. As the name suggests, these minka are basically two structurally independent buildings; they may be either entirely separate, requiring one to go outside when passing between them, or joined to some extent. They are most commonly found in the southern regions of Japan, from Okinawa to southern and central Kyushu. The two buildings of the whole are the hon-ya (本屋), the ‘main house’ with raised floor for living, sleeping, etc., and the earthen-floored oto-ya or ‘cookhouse’, (lit. ‘pot/cauldron house’ 釜屋); they are roughly the same size, and are arranged either with their ridges parallel (the formal name for this arrangement is 平行二棟式, heikou-futamune shiki ‘parallel two ridge type’) or at right angles to one another.

Example of a ie-nakae secchaku minka with the ridges of each building arranged at right angles to each other.

It’s not difficult to understand why this type of minka is found predominantly in southern Japan. In subtropical climates like Okinawa and southern Kyushu, separating the ‘cooking’ and ‘living/sleeping’ functions of a house into two separate buildings means that heat from the stove can be kept out of the main dwelling; another advantage of isolating the hon-ya from the oto-ya is that in the event that the oto-ya is destroyed by fire, the hon-ya will stand some chance of surviving (depending on the wind direction of course!). The scale of these dwellings tends to be quite modest; another advantage of the two-ridge type might have been that the two buildings can be completed in two stages, as funds become available. And of course, as with any vernacular building form, we shouldn’t overlook the cultural factors behind the evolution and persistence of any particular typology or design element, i.e. “that’s the way it’s always been done.”

The ie-nakae secchaku (イエ・ナカエ接着) is one name for a variant of the two ridge minka in which the two building volumes (here termed the ie and the nakae) touch (secchaku) at their eaves, and are joined below by walls to form a relatively unified interior space. The ie, or sometimes omote, are regional variant names for the hon-ya; the nakae is the oto-ya.

Map showing the distribution of various configurations of ie-nakae secchaku minka on the Satsuma Peninsular, southern Kyushu

Where the two roofs meet, a box gutter is provided. In our era when long lengths of sheet metal are cheap and readily available, box gutters are taken for granted; in pre-industrial times constructing a waterproof box gutter was a much more impressive technical feat, using only split bamboo, or perhaps a hollowed-out half-log.

Ie-nakae secchaku minka, showing the box gutter and infill wall where the two buildings meet. The box gutter is a combination of old and new: the (presumably original) technique of split bamboo cleverly lashed together into a kind of Spanish tile arrangement, with the upper convex ‘capping’ sections of bamboo directing water into the lower concave ‘gutter’ sections; and the modern addition of cheap and timesaving sheet metal to make the old bamboo waterproof rather than replace it.

JAPANESE MINKA IX - L-PLAN MINKA

Last week’s post presented a map showing the general distribution of different types of minka across Japan. Today I would like to look more closely at one of the types included in that map that I haven’t yet covered in previous posts on the subject: the magari-ya (曲り屋).

Magari-ya literally means ‘bent house’; in other words, a minka with an L-shaped floor plan. But what really characterises the magari-ya is its particular mode of occupation, of which the plan is merely the spatial outcome: the cohabitation of humans and animals (typically horses) under one roof. The main volume, the omoya or moya (母屋), is for humans; the ‘stable wing’, umaya or maya (馬屋), is for the animals, and the two volumes are arranged at right angles to one another, with each forming one leg of the ‘L’. The umaya usually extends out southwards from the south facade of the omoya, because this position enjoys the best access to sunlight: an indication of just how valuable horses were to the occupants of these houses.

Magari-ya are most commonly found in the Touhoku region of northern Honshu (the main island of Japan).

A map of the Touhoku region, showing modern prefectures by colour and principal cities.

Perhaps the magari-ya variant most synonymous with the form is the Nanbu magari-ya, found in the Touno district of central Iwate (the area was once the domain of the Nanbu clan, hence the name). Taking the former Fujiwara residence as representative, we see that the main entrance to the building is in the umaya volume, placed centrally and very practically at the inner corner where the two volumes meet, and leading directly into the niwa, the earthen-floored utility area. From this central position one can go right to the umaya (which has its own independent entrance, next to the main entrance), left to the daidoko (kitchen) at the rear/north, or around the corner to the partitioned, raised floor section of the omoya, which contains the ‘living’, ‘sleeping’ and formal areas of the home.

A grand example of a nanbu magari-ya, the former Fujiwara residence, Iwate Prefecture. The photo is taken from the west, showing the umaya wing to the rear right, and the omoya in the foreground. The two dark openings in the umaya volume are the main entrance to the niwa (left) and the umaya entrance (right).

Floor plan of the former Fujiwara residence, showing the stable wing (umaya) at the bottom (south).

Another variant of the magari-ya is the chuumon-zukuri 中門造り, which like the Nanbu magari-ya is closely associated with the Tohoku region, but this time on the western, Sea of Japan side. Characteristic of this variant is that the entry (with horse) to the dwelling is via a door in the gable end of the umaya, into the chuumon entry/passage adjacent to the stable, where the horse is left before proceeding through to the earthen-floored niwa in the main interior space of the omoya.

A thatch-walled chuumon-zukuri magari-ya, the former Yamada residence.

Floor plan of the former Yamada residence.

Chuumon-zukuri with a sculpted thatch umaya: the former Satou residence in Niigata Prefecture.

Floor plan of the former Satou residence

It’s striking how functionally similar the plan of the chuumon-zukuri is to that of the modern Australian garage-fronted house, where you enter in your car, ‘stable’ it in the garage, and then go on through into the house proper via a door between it and the garage. You don’t need to be an architectural historian from the future to point out that the size and position of garages in our homes says the same about the status and centrality of the car in our lives as the position of the umaya does about the importance of the horse to the occupants of the magari-ya.

JAPANESE MINKA VIII - DISTRIBUTION

Previous posts in this series presented the basic categorisation system for minka floor plan layouts put forward by Kawashima Chuuji. While this system is satisfactory in a general sense, and is useful in reconstructing the evolution of the minka from its earliest forms, Kawashima himself emphasises that such a neat taxonomy can never really capture the great diversity of minka seen throughout Japan, according to function, occupation, custom, climate, topography, socioeconomic status, and other variables. And what holds true of the country as a whole also holds true when it comes to attempting to identify distributions and patterns of minka by region, whether that be the regional distribution of any particular typology of minka, or the typology of any particular region. While it is understandable that the most typical or common minka type in any area will be held up as representative of that area, it should also be remembered that even within a particular region there will be many variations on the representative type, as well as other types, oddities and anomalous forms that resist classification. Thus it is impossible to create a really accurate fine-scale map of minka types according to region; such a map will be unavoidably low-resolution. Nevertheless, the exercise isn’t meaningless or futile, because the patterns are there, however messy they might be, and the alternative would be an analysis so granular and microscopic that any sense of them is lost. In any case, here is Kawashima’s own map:

Kawashima’s map showing the distribution of minka types across Japan (excluding Hokkaido)

The map’s legend enlarged

The legend reads:

• 広間型および広間的間取り　Hiroma-gata and ‘hiroma-like’ layouts

• ４間取り系間取り（田字型）Yon-madori kei madori (ta-ji-gata) four room layouts

• 曲り屋　Magari-ya literally ‘bent house’ i.e. L-shaped plans.

• 中門造り Chuumon-zukuri A sub-category of magari-ya.

• 妻入り（前土間、片側住居、本棟造り）Tsuma-iri (maedoma, katagawa juukyo, honmune zukuri) Gable-entry minka.

• 二棟造り（主屋無土間）Futamune zukuri (omoya mudoma) ‘Two ridge’ i.e. two building minka (without doma)

• イエ・ナカエ接着 (Ie-nakae secchaku) A form of two ridge minka where the two building volumes are joined to form a unified interior.

• 踏込み土間型 (Fumikomi doma-gata) ‘Step-in’ doma type minka

The hiroma-gata and yon-madori kei madori have been covered in previous posts. The other typologies shown on the map fit less neatly into Kawashima’s classification system; in the next few posts in this series I will look at them in more detail.

GREEN BUILDING PART TWO: IMPLICATIONS

This post will conclude the theme of the last few weeks - energy efficiency and its relationship to environmentalism - by examining the kind of ‘green’ building regulations discussed two weeks ago in light of the concepts introduced last week, and considering their implications on the possibility of ‘green’ building, and on the very concept of the home itself.

As noted last week in relation to automobiles, the Jevons paradox makes clear that any savings made through improved efficiencies, whether that be in energy, material, or space, will be eaten elsewhere; and this is no less true of building than of any other field. Say, for example, you make a more efficient hot water unit: where do the energy savings go? At the household level, the savings may be negated by the occupants, who introduce more energy-consuming devices into their home on the grounds that ‘we can afford it now’. If not, the energy they save will be taken up by others in the context of an increasing population; this is especially true of present-day Australia. Economically speaking, the money they save will either be spent, which is just transferring the consumption elsewhere, or perhaps deposited in an interest-bearing bank account, i.e. lent out by the bank to others, which furthers economic growth, which is also consumption.

Say you change your planning codes to allow, encourage, or mandate smaller, more space-efficient houses on smaller blocks. Is less agricultural land devoured? No: there are simply more people on more blocks on the same amount of land. Say you opt for ‘building upwards’ instead, and put everyone in apartment towers: does the required number of refrigerators, televisions, and washing machines decrease? No: it increases with the increasing number of households, even though each household is now living more ‘efficiently’.

Say you make a more efficient screen or monitor, so that each individual screen uses both less space and less energy (this is exactly what happened in the transition from bulky, power-hungry cathode ray tube screens to flat, energy-efficient plasma and LED screens); does the number of screens per household remain the same? No: instead of one or two screens per household in the 1980s, today there might be dozens.

The above examples reveal the problems and contradictions inherent in goals like ‘energy efficiency’ and ‘green consumption’. Consumption simply shifts to other people or other resources, and worms its way into ever smaller niches and cracks. But what are the implications of all this on the idea of home, in a metaphysical sense, particularly in light of concepts such as Ellul’s technique?

The idea of home is being assailed on two fronts: the regulatory and the material. It is difficult to find the right word to characterise this: the home has been pulverised, powderised, atomised, pinched, dismembered, quantified, disenchanted, bureacratised.

On the regulatory front, there might be no better example of the effect of technique than on that icon and image of the traditional home, the open fire. Once innocent, wholesome, poetic, mythic, a symbol of warmth and welcome, the hearth and heart of the home, the open fire has now been deemed by rational analysis to be, unacceptable, unsatisfactory, inefficient, environmentally unfriendly; its measure has been taken, it must be regulated out of existence.

On the material front, the totalising reach of technique can be seen in the change in timber products over the years. From building with whole logs, to large-section post-and-beam, to 2x4 stud wall framing with hardwood, to the same with softwood, to plywood, then OSB, then MDF, which is the literal powderisation of material: buildings made of sweepings and sawdust. MDF is less wasteful, more efficient, you might say. But none of these timber technologies have slowed deforestation in Australia or anywhere else, let alone reversed it.

The tendency of hyper-rational systems of technique to result in hyper-irrational outcomes is evident in the fact that today you can knock down a perfectly serviceable and sound 150m² brick home from the 1950s, a home that has paid its debt in material and energy terms many times over, and erect in its place a 500m² house with a three car garage, the whole suite of integrated ‘smart tech’ controls, solar panels and batteries, floor-to-ceiling triple-glazed argon-filled windows, and an air conditioner in every room, and as long as it achieves a six (now seven) star energy efficiency rating, it can officially be considered ‘green’. We might be aghast at the ‘waste’ involved in building the kind of primitive huts that were once common in Australia, with their large-section, old-growth hardwood timbers. In truth, the lifetime ‘footprint’ of such a structure would be vastly smaller than any passive or ten-star house. Yet you are not allowed to build and live in such a hut today, because the regulations don’t allow it.

In the 1970s you could obtain a building permit with a single sheet of drawings; today the volume and detail of the regulations and the resultant documentation required of architects and building designers is large and only increasing. The regulatory burden never shrinks but always moves towards growth and complexification, because regulatory bureaucracies (which, as you will recall, form a core part of the network of technique) will always act to increase and protect themselves, until, as Joseph Tainter points out, they eventually fall over. I don’t deny that the motivations behind building regulations are benign: the desire to make buildings safer, healthier, more amenable, less wasteful, is to be applauded. But at the same time the negative effects and deeper implications of this trajectory must also be acknowledged.

So if energy-efficiency regulations don’t in fact protect the environment but instead result in an increase in consumption, what is their point? Here is a challenging proposition: on the principal that ‘the purpose of a system is its outcome,’ this is the point, however unspoken, of such regulations. Not to ‘save the planet,’ but to allow us to continue to live in the manner to which we have become accustomed. The wind turbine and the solar panel are not avatars of environmentalism, they are avatars of consumption; efficiency regulations exist not to reduce consumption, but to make consumption more efficient, which is to say, to encourage it.

GREEN BUILDING PART ONE: CONCEPTS

This week’s post presents several important concepts that I believe should be understood by anybody interested in the subject of energy efficiency as it relates to environmentalism. It is intended to serve as a bridge between last week’s examination of one particular aspect of the recent changes to the National Construction code - an increase in the stringency in the energy efficiency provisions - and next week’s post, in which I will attempt to tie it all together by examining the implications of these concepts on the idea of ‘green’ buildings, and indeed on the deeper meaning of ‘house’ itself.

Technique

Jacques Ellul

In his book The Technological Society (1964), the French philosopher Jacques Ellul defines technique as “the totality of methods rationally arrived at and having absolute efficiency (for a given stage of development) in every field of human activity." As this definition makes clear, Ellul’s concept is not limited to technology in the material sense, but also encompasses process and procedure, methodology, bureaucracy, labour organisation, and so on. In Ellul’s view, technique is not a mere tool or function of people in society, but rather, in James Fowler’s explanation, “the defining force, the ultimate value, of a new social order in which efficiency was no longer an option but a necessity imposed on all human activity” by which “rationalistic proceduralism imposed an artificial value system of measuring and organizing everything quantitatively rather than qualitatively.”

The Jevons Paradox

William Stanley Jevons

The English economist and logician William Stanley Jevons was the first to describe what has become known as the Jevons paradox or the Jevons effect in his book The Coal Question (1865). The paradox is this: any increase in the efficiency with which a resource is consumed will result in an increase in the overall consumption of that resource. Jevons observed that the increase in the efficiency of steam engines - their ability to do more work with the same amount of coal, or use less coal for the same amount of work - resulted in an overall increase in the consumption of coal, not a decrease. This is because more efficient steam engines are cheaper to operate and thus become economically viable in a wider variety of applications: although the amount of coal required per steam engine to do a given amount of work goes down, the total number of steam engines, and the total consumption of coal, goes up.

The Jevons paradox is more of a counter-intuitive statement than a true paradox, but ‘paradox’ has proven to be a good term, as it gives a sense of just how resistant so many people are today to really internalising its meaning. Not because it is a particularly difficult concept to understand, but because it cuts to the heart of, and has uncomfortable implications for, the dream of ‘green’ or ‘environmentally friendly’ technology and the whole superstructure of technique that has grown up around it. The Jevons paradox gives the lie to the ideal of efficiency in the service of the environment, by pointing out that any energy or resources you save will just be used by someone else.

Perhaps rather than ‘counter-intuitive’ we should call the Jevons paradox ‘counter-ideological’, because the validity of entire green industry rests on the implicit assumption that the opposite is true: that an increase in the efficiency of consumption results in a decrease in overall consumption. To paraphrase Upton Sinclair: it is difficult to get a man to understand something when his worldview depends on his not understanding it.

Complexification

Joseph Tainter

In his book The Collapse of Complex Societies (1988), the American anthropologist and historian Joseph Tainter puts forward the thesis that technology plays a major role in the collapse of civilisations. Very simply put, the mechanism is this: problems are identified in society and novel technologies are developed to solve them; these technological solutions by their nature give rise to new problems, which in turn give rise to new technological solutions, and so on, with technology or technique piling on itself, increasing like the heads of the Hydra in a fractal-like multiplication and elaboration at ever-finer levels of complexity.

As an example of this phenomenon, Tainter has given the problem of vehicular CO2 emissions, which resulted in the mass-market hybrid car, where the solution was arrived at by providing cars with two power units instead of one, representing a huge increase in complexity. The solution itself was arguably a success, given that hybrids like the Toyota Prius can achieve fuel efficiencies of around 5 litres per 100km, impressive numbers when compared to a modern internal combustion-only car, but still only about the same as the Citroen 2cv, first produced in 1948.

But what about purely electric vehicles like the Tesla? you might ask. The increase in complexity in modern vehicles is not limited to the powertrain, of course: it is also driven by comfort, safety, the need for speed, reliability, and a whole host of other factors. I don’t mean to suggest that these things are bad, or in any way not genuine improvements, just that we should also accept that they come with costs. Electronification in particular has vastly increased the complexity of cars, and has been made possible by the invention of the transistor, then the integrated circuit, then increases in the processing power of silicon chips and the efficiency of their manufacture.

Weight is a good proxy for complexity in cars: the 2cv weighs in at around 585kg; a Prius is more than double that at around 1200kg. Teslas weigh anywhere from around 1700kg to 2400kg, and a single Tesla battery alone doesn’t weigh that much less than an entire 2cv. These weights are representative not only of energy consumption per unit distance, whether than be petrol or electricity, but also of the sheer amount of material and energy embodied in the manufacture of the vehicle itself.

Here we see the Jevons paradox at work, both at the resource level and at the product level: despite increases in chip efficiency, world silicon production has increased from around 4 million tonnes annually in 1990 to around 9 million today; cars per unit are ever-more efficient in their fuel consumption, but the total number of cars produced goes ever upwards.

Fungibility and Liebig’s Law

Carl Sprengel

In discussions of resource availability and depletion, it is often assumed that resources are fungible: that is, when any particular resource becomes unavailable or too expensive through scarcity, it can simply be swapped out for another without significant effects. This assumption is especially common in regard to energy, the ‘master’ resource upon which the extraction and utilisation of all other resources depend. As the thinking goes, coal replaced wood as the primary energy source at the beginning of the industrial revolution, then oil and gas overtook coal, and now ‘renewable’ energy sources such as solar, hydro, and wind are poised to replace fossil fuels. This leads us to Liebig’s law, or the law of the minimum, developed by the German botanist Carl Sprengel in 1840. Liebig’s law states that the growth or health of any system is limited not by the total resources available, but by the availability of the least available resource. To illustrate this concept, let’s take an example from agriculture, the field where Liebig’s law was first formulated: it doesn’t matter if you have perfect rainfall, sunlight and heat, and your soil is perfectly balanced in all other essential minerals; if the soil is deficient in nitrogen, then it is the level of nitrogen that will determine the ultimate health and yield of your wheat crop.

A joule from a wind turbine may be fungible with a joule from a coal-fired power plant, but this doesn’t mean that the energy sources themselves are equivalent in other ways. Fossil fuels are taken so for granted that it’s easy to forget what a miracle they are in terms of their energy density, storability, and ‘readiness’. Coal in particular can be literally dug out of the ground and burnt to obtain energy without processing or any other intermediate steps. Wind turbines must be built (of large amounts of concrete, steel, fibreglass, and rare elements), transported, erected, and maintained, and all of these stages require their own energy inputs; they have a limited lifespan and eventually fail; and they are ultimately harvesting a low-density source of energy: wind (which is really a form of solar energy). The same things are true of photovoltaic solar. People will often counter these objections by an appeal to technological omnipotence: claiming that when rare-earth elements become scarce, we will go to space and mine them from asteroids; or that wind turbines will eventually be made by and with self-replicating bacteria; or some other iteration of “they (scientists) will think of something.” But these fantasies are based on nothing more than a kind of quasi-religious faith in technology and progress.

The Citroen 2CV

THE NATIONAL CONSTRUCTION CODE 2022

I would like to take a bit of a detour today, away from the recent focus on Chinese vernacular architecture and into some ‘talking shop’. This is prompted by the recent adoption (on May 1st 2023) of the new National Construction Code, which replaces the previous NCC released in 2019.

For those unfamiliar with the NCC, the Victorian Building Authority website provides this explanation:

“The National Construction Code (NCC) sets out the requirements for the design and construction of buildings in Australia, including plumbing and drainage work. It sets the minimum required level for the safety, health, amenity, accessibility and sustainability of certain buildings.”

The NCC has previously been comprised of three volumes:

Volume One, The Building Code of Australia Volume One, which covers mainly Class 2-9 structures;

Volume Two: The Building Code of Australia Volume Two, which covers Class 1 and 10 structures; and

Volume Three: The Plumbing Code of Australia.

The 2022 NCC retains this basic three-volume structure, but also introduces significant changes and additions to the organisation and content of the Code.

The deemed-to-satisfy solutions for Class 1 (basically houses) and Class 10 (garages, carports and the like) structures, which used to be contained in Volume Two, have been split off into a new document, the ABCB (Australian Building Codes Board) Housing Provisions Standard 2022; Volume Two now contains only the performance solutions for Class 1 and 10 structures.

There is a whole new Section to the Code, “Liveable housing design,” which is presented in both Volume One (as Part G7) and Volume Two (as Part H8), and also in its own dedicated Standard referenced in these Parts: the Australian Building Codes Board Liveable Housing Design Standard 2022. This Standard contains new requirements (to come into effect in Victoria on October 1st 2023, after a five-month transitionary period where adoption is optional) intended to ensure that new dwellings “better meet the needs of the community, including older people and people with mobility limitations.” It is an adaptation of the ‘Silver’ level requirements of the Liveable Housing Design Guidelines (LHDG) 2017, but essentially makes mandatory in private dwellings certain design elements that until now had been optional: things like step-free access to dwelling entrances, minimum clear widths for openings and corridors, accessible bathrooms, and the like. Previously such measures were generally only required in public buildings, with the specifics given in Australian Standard 1428 - Design for access and mobility.

The other major change to the Code is an increase in the stringency of water use, energy efficiency (to the tune of around 30%) and condensation mitigation requirements. The new energy efficiency requirements are contained within Volumes One (Section J) and Two (Part H6), and also in the Standards referenced therein: the ACAB NatHERS (Nationwide House Energy Rating Scheme) Heating and Cooling Load Limits Standard 2022, and the new ACAB Whole-of-Home Efficiency Standard 2022. The NatHERS scheme is used to provide a streamlined pathway to achieving the energy efficiency standards required by the NCC, and it assigns a star rating to new dwellings; the minimum rating required, previously six stars, is now seven. Likewise, although NatHERS has contained heating and cooling load limit provisions since 2019, those required by the 2022 edition are stricter.

The new Whole-of-Home Efficiency Standard, as explained in its introduction, “provides a holistic assessment of the energy performance of a dwelling, covering both thermal performance and domestic services. To meet the WOH requirements, the net equivalent energy usage of a dwelling must not exceed a certain allowance.” This is in contrast to the approach adopted by the NCC and NatHERS until now, which has been more focused on managing “heat transfer through the building envelope to separately minimise heating and cooling loads.”

All this represents significant complexification and growth of the Code over the previous edition, and is indicative of a larger general phenomenon. Next week, I would like to explore its implications from a more abstract and holistic perspective, and consider what it means to be ‘green’.

CHINESE VERNACULAR DWELLINGS IV

As mentioned in last week’s post, timber construction doesn’t easily lend itself to building at extremely large scales or in multiple storeys, and traditional Chinese architecture is no exception here: there are relatively few examples of large timber structures in the historical record. Timber architecture does however encourage a degree of systematisation or ‘modularity,’ if those terms can be applied to pre-industrial structures, and this has been the case with the ‘hall’ (tángwū 堂屋), whose gradual standardisation has meant that it displays little variation over time and region. These factors go some way to explaining the agglomerative character of Chinese architecture: increases in scale and complexity are achieved not by the erection of grander and more complex unified structures, but by the addition or duplication of relatively modest and simple groups or ‘units’ of tángwū and their associated courts (院子 yuànzi).

The tángwū and yuànzi present a beautiful contrast. Against the simple, rectangular and relatively unchanging form of the tángwū, we see in the yuànzi an infinite variety of sizes, forms, functions, and atmospheres. It is tempting to interpret the two in almost yin-yang terms: the tángwū is rigid, stable, material; the yuànzi is spatial, fluid, yielding, freely receptive and responsive, with the capacity to accomodate the creative energy which finds no outlet in the tángwū. Indeed, when we speak of Chinese architecture increasing in scale and complexity in response to emergent societal conditions and requirements, it is in the yuànzi, not the tángwū, which this response is expressed, and to the Chinese people it is the yuànzi, not the tángwū, that is in every way the heart of the architectural ensemble.

CHINESE VERNACULAR DWELLINGS III

Last week’s post examined at the nature and evolution of one of China’s most characteristic vernacular dwelling plan-forms, the sìhéyuàn (四合院), via the book Exploring Space in Chinese Residential Architecture. Here I would like to take an introductory look at one of the two fundamental elements of these dwellings: the basic building unit or ‘hall’ 堂屋 tángwū (the other being the courtyard 院子 yuànzi). It could be said that the essential nature and form of Chinese architecture is distilled in these two elements and their relationships, and they are found everywhere, across eras and regions, from the grandest temples and villas to the most humble dwellings.

At the heart and beginning of Chinese architecture is the concept of protection. From the earliest recorded history, the Chinese have sought to defend their living environments from threats of invasion by foreign enemies, winter winds, and sand storms by erecting walls to enclose them. From the neolithic period, clusters of dwellings have displayed a centripetal character, and from the Xia Dynasty (c. 2070 - c. 1600 BC) we already see the pattern of tángwū being situated at the north, south, east and west of a central inner courtyard. This form, the sìhéyuàn, reached its maturity in the Han Dynasty (202 BC - 220 AD), and has continued down until the present.

The age-old Chinese practice of erecting thick, sturdy earthen walls around dwellings, villages, and cities, not only to fortify them against the ‘outer’ but to clearly demarcate the ‘castle’ and consolidate the sense of the ‘inner,’ has given rise to the development of a unique, hermetic world within these walls and cloisters, with the oppositional relationship between the tángwū and yuànzi at its core.

As historical sources indicate, the structural basis of Chinese architecture has always been the axial timber frame, and the tángwū is no different. Such a structural system is not really capable of producing large, complex buildings, and the simple, pure plan-form of the tángwū is an expression of this orderly, ‘modular’ structural system, rather than being expressive of any particular function. Though the use and scale of tángwū may vary, they all share the same basic essential characteristics: the orderly arrangement of columns, typically a single span in depth but sometimes more, an odd number of bays, an open ‘front’, and a closed ‘back’.

Elevations showing a range of tángwū, from the simplest three-bay pattern all the way up to nine and eleven bay examples.

The building of a tángwū involves first constructing a raised platform or podium, typically of compacted earth or rubble faced with stone, then erecting on it the building itself, with its entry and all openings in the long southern facade facing a courtyard or open area, blind rear and gable-end walls, and a hipped or gabled roof.

Cutaway perspective of a tángwū, showing the central táng ‘living’ area and wòshì ‘bedrooms’ to either side of it.

The fact that tángwū always have an odd number of bays is thought to have arisen both from the influence of yin-yang philosophical concepts, and also from the desire to grant the ‘chief’ or head of the household a physical position within the tángwū that gave full dignity and expression to the functional centrality of his role. The central bay of the tángwū occupied by the head is called the 堂 táng. The odd number of bays, with an equal number of bays (typically bedrooms, 臥室 wòshì) on either side of the central táng, the central entry steps leading to the táng, and the role of the táng as the ‘gatekeeper’ space which must be passed through to access the other areas of the building, all emphasise the centrality of the táng and the importance of the axis that runs through its centre, and give the tángwū as a whole a strong sense of overall symmetry.

Diagram illustrating the highly symmetrical form of the tángwū and the importance of the central axis.

CHINESE VERNACULAR DWELLINGS II

This post continues on from last week’s in taking a look at the contents of the book「中国民居の空間を探る」“Exploring Space in Chinese Residential Architecture”.

As good a place to start in any exploration of this subject is with one of the most representative and archetypal plan-forms of Chinese vernacular dwellings (民居, mínjū): the sìhéyuàn (四合院). In this post I would like to attempt to summarise the book’s introduction to this particular building typology.

The sìhéyuàn is an arrangement in which four (四sì) wings, or independent buildings, are arranged in a square or near-square around a central courtyard (合院 héyuàn). These wings or independent buildings are probably best described under the Japanese catch-all counter for buildings, 棟 (tou, literally ‘roof ridge’), which accurately captures the fact that each wing or building has its own pitched roof (gabled at its free ends) with a central ridge that slopes down to front and back. The history of the sìhéyuàn goes back over 2,000 years, typically seen as the relatively luxurious dwellings of the upper classes; sìhéyuàn can be found all over the country, with many variations according to local climatic, environmental, and other conditions.

The best way to understand the sìhéyuàn is to trace its evolution from simpler forms. We begin with the 横長方形住居 (Japanese: yoko chōhōkei jūkyo) pattern, a single-storey, single tou, rectangular building, arranged with its long axis oriented east-west, a south-facing facade with large openings to admit as much of the available southern sun as possible, and a completely blind northern wall to protect against winter cold. Most examples of the yoko chōhōkei jūkyo are divided into three or more bays, with one primary central ‘living’ bay, and the remaining bays, typically for sleeping, symmetrically arranged to its left and right. This arrangement as a whole is called a 堂屋 tángwū or ‘hall’; the prototypical three-bay tángwū is called the 一明二暗 yī míng èr àn, literally ‘one light two dark’. In many cases, the whole site of the dwelling is walled, with the building situated at the northern part of the resulting enclosure; the southern part is left as open space, but this ‘negative’ space is not considered to be a courtyard (院子 yuànzi) proper, because it is weakly formed by the perimeter walls, not by buildings (Fig. 1).

Fig. 1

The prototypical yoko chōhōkei jūkyo form eventually evolved into a more complex arrangement of three tou, arranged in a U shape open to the south, known as the 三合院 sānhéyuàn, which first appeared in the north-east of China before spreading to the other regions.

There are three subtypes of sānhéyuàn. In the first, the three tou are completely independent structures; though these structures clearly define (and mark the first appearance of) the true ‘positive space’ courtyard (院子 yuànzi), and establish a relatively close relationship between the courtyard and the main living area (堂táng), the courtyard in this arrangement still lacks a strong sense of intimacy (Fig. 2).

Fig. 2

This sense of intimacy is only gained when the three tou are unified into a single building, as in the second type of sānhéyuàn, in which the basic east-west oriented yoko chōhōkei jūkyo is extended southward at each end (Fig. 3), eventually forming a fully continuous U around the yuànzi (Fig. 4). This form is often seen in farmhouse dwellings, and the southern side of the yuànzi is left open.

Fig. 3

Fig. 4

The third subtype is similar to the second, the only difference being that the southern side of the yuànzi is fully closed off by extending a wall between the southern ends of the east and west wings (Fig. 5). There are also two-storey examples of this type, more commonly seen in urban settings.

Fig. 5

The step from sānhéyuàn to sìhéyuàn is relatively straightforward: the southern side of the yuànzi is infilled, not with a wall as in the third subtype of sānhéyuàn, but with a fourth tou, thus forming a courtyard enclosed on all four sides by buildings (Fig. 6). The entry gate (大門 dàmén) to the complex was typically placed on the central axis in the southern wall, though from the Song Dynasty (960-1279) onwards there are also many examples with the dàmén at the south-east corner, as a result of fēngshuǐ considerations.

Fig. 6

Each of the four volumes in the sìhéyuàn is a 堂屋 tángwū in itself, typically the 一明二暗 yī míng èr àn three bay type, with a central 堂 táng flanked on either side by an auxiliary sleeping bay. In effect then, the sìhéyuàn is a rotational quadrupling of the yī míng èr àn around a central courtyard, with the internal facade of each tángwū open to the courtyard, and the ‘back’ walls facing away from the courtyard left blind. In examples where the four tángwū are unified into a single building, the resulting corner rooms are typically ‘servant’ spaces, for activities such as cooking and washing. The tángwū lack internal corridors; the auxiliary bays are accessed from its central táng. Movement between each táng is via a corridor or cloister (廊廊 zǒuláng) ringing the yuànzi; the zǒuláng is protected with a shallow, low roof but is open on the side facing the yuànzi, and serves to unify the whole composition, not only functionally but also by modulating the transition between interior táng and exterior yuànzi (Fig. 7).

Fig. 7

CHINESE VERNACULAR DWELLINGS I

I’ve been looking through the book「中国民居の空間を探る」“Exploring Space in Chinese Residential Architecture” with the unwieldy subtitle「群居類住　ー　光・水・土 中国東南部の住空間」“Communal Living - Light/Water/Earth - Residential Space in Southeast China”, by 茂木計一郎 (Mogi Keiichiro) et al., published by 建築資料研究社 “Architectural Resource and Research Corporation”, 1991, 247 pages.

The book presents the results of research trips taken by a group from Tokyo University of the Arts in the 1980s, and is a fantastically detailed study of a variety of Chinese vernacular residential building types, including the famous tulou (土樓, literally ‘earthen structure’) fortified communal dwellings of Fujian province.

Bird’s eye view of a group of tulou.

Interior courtyard and cantilevered balconies of a tulou.

Facade of a tulou. The massive earthen walls taper as they rise and slope inwards for stability. Note also the fortified elements: blind lower storeys and a stone-reinforced entrance.

The book is a great resource for anyone interested in the subject, even for those who don’t read Japanese; it is informative and pleasurable enough just to look at the huge number of photographs and floor plans, street plans, diagrams, sections, cutaways, and detail drawings, all beautifully and finely drawn. It is also a valuable resource in that it is safe to assume that many, if not most, of the buildings and streetscapes documented have since been demolished, given the immense economic development experienced by the region in the decades since the book’s publication.

Something that will immediately jump out at any reader who is far more familiar with Japanese architecture is the Chinese predilection for symmetry in plan and elevation, even in relatively modest residential buildings. The Japanese, in contrast, seem to have an innate dislike of too much symmetry, and will rarely miss a chance to ‘sabotage’ it in one way or another, even in formal religious buildings.

OPPOSITE DIRECTIONS

It’s one thing to write in the abstract about the theoretical differences between traditional and modernist architecture, and to study pictures and diagrams of traditional and modernist buildings. But it’s only when you encounter the two architectures starkly juxtaposed ‘in the wild’ that you are really struck by the living difference between them, not only in the buildings themselves but in their effect on the atmosphere of the place. As in the example of the two buildings shown below, the photos of which were taken by standing in the exact same spot, but facing in opposite directions.

THE SHIP OF THESEUS: PART THREE

In this final (probably) post on the Ship of Theseus and the question of architectural authenticity, I would like to consider the example of Australian mountain huts that have been lost in fires and later rebuilt. In particular, Delaneys hut in Kosciuszko National Park, which has now been rebuilt twice after being destroyed in bushfires: once in the mid to late 2000s after the fires of 2003, and again this year after the fires of 2019-2020.

The original Delaneys Hut, built circa 1910, Kosciuszko National Park.

The original Delaneys Hut after its destruction in 2003.

Delaneys Hut during its first reconstruction.

The first reconstruction. Note the horizontal rails to the timber slab chimney, reasonably faithful in design to the original.

The first Delaneys Hut reconstruction after its loss to fire in 2020.

The second reconstruction of Delaneys Hut under construction, due to open to the public in April 2023. Note the fire-treated cladding and ridge-mounted sprinkler system.

Another view of the second reconstruction. Note that the chimney now lacks horizontal rails, and has gained a cowl.

Comparing before and after photos of these huts, the thought occurred that is probably easier to successfully reconstruct a work of classical or ‘high’ architecture than it is to rebuild a vernacular building, because classical buildings are more formally and precisely designed and thus more easily ‘abstracted’ into a set of measured drawings and other documents that capture the ‘essence’ of the design; in the terminology of aesthetics, they are more allographic and thus more reproducible, more akin to composed music or a written work. In vernacular buildings, the authenticity arguably lies more in the process of production; they are more autographic, like a painting or a sculpture. Does this then mean, somewhat paradoxically, that aiming for a ‘perfect reproduction’ of a lost vernacular original is actually against the spirit of vernacular building? Perhaps the attitude expressed by one of the men who worked on both Delanys Hut reconstructions is in fact the correct one: “I didn't need a plan this time because I still had it in my head."  

If you are interested in learning more about Australian bush huts, this is an excellent site.

THE SHIP OF THESEUS: PART TWO

Continuing on from the conclusion of last week’s post on the issues raised by the Ship of Theseus thought experiment and the importance of process, or craft, in the consideration of the ‘authenticity’ of traditional architecture and vernacular building (that we call it vernacular building is itself a clue to the importance of craft in the character of vernacular buildings), I would like to consider a local example.

In architecture, Ship of Theseus scenarios play out not only as ‘plank-by-plank’ transformations via the progressive replacement of decayed or broken parts over a long period of time, as in the original myth, but also, and perhaps more often, as wholesale ground-up reconstructions of historically important buildings that have been lost to fire, war, and the like. We almost got to see such a reconstruction in Melbourne, Australia, a few years back, when developers illegally demolished the Carlton Inn (c. 1856), one of the oldest surviving buildings in Carlton. The City of Melbourne at first sought to force the perpetrators to rebuild the building brick-for-brick, and it would have been interesting to see what resulted: whether the reconstruction would have been true ‘in spirit’ as well as in form, or whether most of the fractal texture would inevitably have been lost through the use of modern ‘precision’ industrial materials and techniques.  Presumably at least some of the original material of the building could have been salvaged from the demolition site and reused in the reconstruction; whether this would have been proportionally enough of the whole to carry the entire building is an open question. The stamp of authenticity imparted by things like handmade bricks is taken in at a glance, and is so subtle as to operate on an almost unconscious level.

The Carlton Inn as it was in the early 20th century (1920s?).

The building in more recent years.

The building during its demolition.

The ‘park’ that currently occupies the site.

Unfortunately all this will have to remain at the level of speculation, because the developers in the end received only what essentially amounted to slap on the wrist: fines totalling far less then the increase in value of the land they achieved by demolishing the pub (something they had no doubt factored in to their risk-reward calculation when deciding to undertake the demolition), and an order to establish a temporary and perfunctory park on the site, until its inevitable occupation by another generic modernist high-rise development.

The ironic thing is that the Victorian architects and builders responsible for the Carlton Inn’s design and construction, and indeed the architects and builders of the traditional age of architecture more generally, would not have been that bothered by the building’s destruction. Brimming with confidence, the Victorians were not so concerned with preservation, because they were sure that whatever they replaced lost buildings with would be, if not identical, at least equal in quality: quality of design, quality of materials, and quality of craft.  Part of the impetus and urgency behind the preservation of ‘historical’ (actually traditional) buildings today is the knowledge that, in the vast majority of cases, we are not capable of matching the quality of the buildings we demolish, in any category.

THE SHIP OF THESEUS: PART ONE

In Greek mythology, the Ship of Theseus is the ship in which King Theseus returned from Minoan Crete to Athens, where it was maintained in seaworthy condition for centuries by replacing its decayed parts with new, until eventually nothing of the original ship remained. In philosophy, the story is used as a thought experiment to prompt contemplation of the notion of identity: does an object that has had all of its original constituent parts replaced remain the same object? Does the identity lie in the form only, or also in the content?

Probably the most famous example of the ‘form over content’ approach to architecture is the Ise Jingu, or Ise Grand Shrine, in Mie, Japan, whose buildings have been dismantled and constructed anew (on adjacent sites) over 60 times going back around 1,300 years. Other than in periods of war or other disruption, reconstruction takes place every 20 years; the last in 2013 cost over half a billion dollars. The forms and details of the buildings have remained largely unchanged over the centuries, providing invaluable insights into the history and development of Japanese architecture; perhaps even more importantly, the reconstruction process also plays a crucial role in preserving and handing on the knowledge, techniques, and traditions of the various trades involved; to the form/content binary we should perhaps add a third element, process. These practical, constructional aspects are usually given less emphasis in writings on traditional architecture than are issues of ‘form’ and design theory, which is not really surprising given that most writers on traditional architecture tend to be architects and are thus understandably focused primarily on design. But the viability and even the ‘authenticity’ of traditional architecture lies as much in the hands of the tradesman it as it does in the hands of the designer.

Ise Grand Shrine buildings

Aerial view of Ise Grand Shrine, showing extant buildings on the left and the vacant site awaiting the next reconstruction on the right.

VERNACULAR PICTURES 15: JETTYING

The traditional practice of projecting the upper storey or storeys of a building horizontally out beyond the ground floor footprint, by the use of cantilevered (supported at only one end) or bracketed beams or joists, is called jettying (the word is cognate with jut and project). In the past, jettying was commonly employed in urban areas as a way of increasing overall floor area by extending the upper storey or storeys out into the ‘airspace’ of the street, something that modern planning codes no longer allow.

As noted, jettying is a form of cantilever, but modern cantilever-as-feature architecture is an entirely different beast to the modest projections of traditional jettied buildings. Whereas the reach of the traditional jetty was limited to the bending strength of practically obtainable timber beams, steel and reinforced concrete allow for much greater cantilevers; for even more extreme projections, the whole volume can be engineered as a giant box truss, formed by steel structural members within the floor, walls and roof.

A huge cantilever with structure exposed, showing how the whole volume constitutes a giant truss.

While undeniably impressive from an engineering perspective, these extreme cantilevers tend to induce anxiety and a sense of imbalance. Humans have a finely-tuned instinct for what is structurally stable (if these cantilevered volumes were boulders balanced on other boulders, would you stand on their edges, or walk underneath them?), and knowing that these structures have been carefully designed so that they will not collapse does not reduce this fundamental feeling of unease. It’s also interesting that despite superficial or cosmetic differences, these ‘wow-factor’ cantilevers are essentially all the same, to the point of cliche.

VERNACULAR PICTURES 14: AGEMISE AND SHITOMIDO

Any designer can tell you how satisfying it is to find a design solution that allows a single element to perform ‘double duty’ by fulfilling multiple functional requirements, and it’s always a pleasure to come across examples of such solutions in vernacular buildings. Two such examples from Japan, in a way the mirror image of each other, are the agemise and the shitomi-do.

The agemise or battari-shogi is a fold-down timber platform or bench for the display of wares (or for sitting on) in front of a machiya townhouse. In its folded-up position, it can either sit in front of a blank wall, or in front of a koushi lattice that fully covers the main opening or the facade, or it may itself form part of the security arrangement over the opening; it also provides impact and intruder protection to the lower half of the opening, and when folded up, sends a clear ‘we are closed’ signal to passers-by. When folded down, it forms a kind of extension of the interior floor out into the street.

Fine example of an agemise folded up against the koushi of a machiya facade.

Agemise folded up to form the lower half of the protection to the openings, with the upper half formed by folding shutters.

Folded-down agemise showing their function as platforms for the display of goods, in this case books.

The shitomi-do is a top-hung lattice shutter most closely associated with Buddhist architecture. It covers either the full opening or, as is more often the case for openings that extend to the floor, only the top half. It is usually held open in a horizontal position, on hooks at the ends of iron struts that hang town from the eaves; shitomi-do are usually well protected from the weather by the deep eaves of the roof above.

Lattice shitomi-do in the open position on a Buddhist temple building.

Top-hung shutters can also be found in vernacular applications, where they are often more exposed to the elements, and so also function to provide protection to the opening from sun and rain. These vernacular examples are usually board-clad rather than latticed, so are not strictly shitomi-do; the other main difference to their architectural counterparts is that they are usually propped open in an angled position, on angled timber struts that rest on the sill of the opening.

Rustic top-hung shutters propped open on a building in Okinawa.

More refined example of top-hung shutters.

Top-hung shutter to a small unglazed window.

Looking out through half-opened shutters. This image illustrates another of the functions served by top-hung shutters: that of filtering or ‘muting’ the view.

Example showing agemise and top-hung shutters used in combination.

VERNACULAR PICTURES 13: THE DESIGN ENVIRONMENT

This blog focuses on traditional architectural design, so it is easy to overlook or forget the fact that any designed object can be designed in a traditional manner; indeed, in the not-so-distant past, all designed objects were traditional in their design. It is interesting to speculate on the positive impacts of living in such a design environment (or what Kon Wajiro called the fudo), where not only the buildings but every object, from the most rustic and utilitarian to the most refined and ornamented, was worthy of aesthetic contemplation, and contributed to the psychological wellbeing of the people who moved amongst and interacted with them, whether taken for granted at a conscious level or not. Even machines were traditional in their design and ornament. Compare this world with the ugly chaos of our own design landscape: take any modern design object with a historical continuity of at least 100 years, and line it up next to its ancestral counterparts. It is an understatement to say that the modern designs don’t come off well in the comparison.

19th century bollards. Old cannon barrels were often used as bollards, and the design was so well liked that eventually bollards were purposely cast in this shape.

Modern bollards.

An early 20th century car: the Ford Model T

A modern car

A 19th century cash register

A modern cash register

And before anyone objects that ‘materials like timber and brass are no longer affordable, nor the labour involved in ornamenting them’ — this may be true, but there is no practical reason whatsoever why traditional design and ornament can’t be achieved in injection-moulded plastic or other modern materials.

VERNACULAR PICTURES 12: THATCHED ROOFS

The thatched roofs of Japanese minka farmhouses are an indispensable part of their overall character. These monumental, steeply pitched roofs might be oppressive or overwhelming if clad in any other material, but the inherent softness of thatch and its fine-grained, almost porous texture gives these buildings a distinct warmth and an impression of welcome and shelter.

Thatch is probably the most sculptural of all roofing materials: its smooth, rounded hips and valleys, uninterrupted by capping or flashing; the creative and even fanciful solutions it allows in resolving complex intersections; and its great thickness, fully expressed at the eaves, are all difficult or impossible to recreate in any other material.

A cold-region minka with not only thatched roofs, but thatched walls: thatch is an excellent insulator.

Thatched roof with a beautifully smooth valley transition. Note also the grasses and even trees growing from the ridge capping.

A fine example of the subtle sculptural possibilities of thatch.

Due to fire concerns, thatched roofs have been absent from Japanese cities for hundreds of years, long replaced by tile. Unfortunately, thatch has also become a rarer and rarer sight in the Japanese countryside, due in large part to the fact that for most people, thatching only makes sense economically if it is undertaken as a communal effort, with each villager volunteering their labour in the harvesting of reeds and laying of the thatch, under the direction of a skilled thatcher, and each receiving help in their turn when it comes time to rethatch their own roof. The communities and community structures required for this reciprocal system to work barely exist any more, and to pay a professional crew to rethatch a roof is prohibitively expensive.

Incidentally, a thatched roof isn’t strictly waterproof. It relies on its thickness and the careful orientation of the ‘fibres’ or individual reeds within the body; they are laid at an angle slightly shallower than the pitch of the roof as a whole, just as tiles are. In extremely idealised terms, a drop of rain hits the topmost layer of reeds, travels along it for a distance, falls through onto the later below, travels along that, falls again, and so on; the thatch layer must be thick enough so that by the time the drop of water penetrates through to the underside, it is outside the wall of the building and exits the thatch at the eave.

Simplified and idealised diagram of how rainwater ‘travels’ through a thatched roof and exits at the eave.

Thatching has never been a part of the Australian vernacular landscape. The industrial revolution was already well underway in Britain by the time European settlement of this country began, and from the very earliest days roofs in Australian towns tended to be of corrugated iron or slate, both brought out from Britain as ships’ ballast. Outside of the more populated areas, settlers’ bush huts tended to use bark or boards as a roofing material, sourced from trees felled on site. At any rate, the dry climate means that the marshy areas needed to support the growth of reeds are relatively rare; add to that the ever-present risk of fire, and thatch was never going to be a viable proposition here, unlike in Britain. But steel roofing, probably the most common roofing material in Australia, in corrugated and other profiles, presents its own sculptural possibilities; these have barely yet been explored.