D.H Lawrence once remarked on a conversation he had with an Australian soldier who told him how comforting he found the sound of rain on the tin roofs of huts when he was away at war: it reminded him of home. Corrugated iron seems to have been a constant and obvious feature of the Australian built environment. It's there in the street awnings that shade the footpaths of our cities, it's there in the massive industrial factories and warehouses on the edge of town. And of course it's there in the woodsheds and water tanks of rural Australia.

But we tend to have very mixed feelings about iron and steel in architecture. Let's explore that ambivalence with architect Alan Ogg whose winding academic career through engineering, philosophy and architecture eventually led him to his first book which was an award winning study of steel in Australian architecture and the Sydney architect James Grose who uses steel extensively in his work and who must need a very big tin shed to house the many national and state awards he's won in recent years.

James, you grew up in Bundaberg in Queensland where there are enormous corrugated iron sheds serving the sugar industry. Is it too romantic to suggest that you found here at an early age your appreciation for steel architecture?

James Grose: I'm sure that's where I became aware of it and have brought it into my work, because the sort of agricultural architectural stock in Australia is really where a lot of us architects who were born in the country get our language from, and also combining that with a sort of modernist education in architecture where function is about in agricultural buildings getting rid of any unnecessary stuff, where you're aiming to make a huge span with as little amount of material as possible. Then those two things neatly dovetail to use a timber expression, together.

Alan Ogg: It's also used in the early ironwork of course as the transition was made from timber buildings into iron buildings. And there are many details in very early iron structures which in fact modeled very closely details in timber. This is a very interesting part of any switch, technological switch, in this case the use of materials.

So Alan what's behind your respect for steel as a building material?

Alan Ogg: I would like to think I would have respect for most building materials. I certainly have an interest or developed a very keen interest in steel because it was one of the subjects which I had to teach young architecture students at the university construction techniques and so on and one of the difficulties I found was that I was teaching the design studio where the focus was on design but I was also teaching structural and constructural matters in another forum. And it seemed to me that there were an awful lot of things that needed to be talked about, which didn't fit precisely well in either camps. There needed to be a way of talking about a material in terms of the ideas which generated the use of that material, and in large part that's the direction that my book took to explore not only the technology which surrounds a material but also the ideology, the architectural ideas which have surrounded the material and its use.

You say in your book that the first iron arrived in Australia on the manacled legs of convicts and there's been no turning back in how we've embraced it. From this inauspicious beginning, James Grose, to what extent do you think that the use of iron and steel in architecture in this country has registered on the national consciousness?

James Grose: Well I often reflect on one occasion (in 1992 I think) when several of my colleagues and I were in Venice for the Biennale exhibition, which is the biggest exhibition of international architecture ever. Each country had a pavilion and Phillip Cox designed the Australian pavilion and everyone who went into that building was overwhelmed by the lightness, meaning control of light, but also the lightness and elegance of the structure. And then you'd go over to the Italian pavilion and see heavy ponderous sort of big masonry thing. And that's when it occurred to me that building in steel has become now very important to establishing the difference or the otherness between Australian architecture and other architectures, and I think that it has become the real language of Australian architecture.

It's interesting that you talk about the ponderousness of the Italian building, there's a sense that stone has prestige, that it's a significant material?

James Grose: Well yes that's true and masonry meaning anything from rocks through to fabricated bricks is very much like this translation of an idea in architecture, such as the idea of enclosure must be of a terrestrial nature. In other words we are humans and we occupy the ground. Now my attitude to using steel in the more rural based buildings that we've done is that these things are temporary, they move on, they go into the ether or whatever, and that's the nature of Australian occupations.

Perhaps even now we tend to think of steel and iron as being structural elements which should be hidden. There should be cladding of some kind around it.

Alan Ogg: From the middle of the 19th century onwards, a lot of architects were eventually persuaded that here was a way of spanning, a way of building which was undeniable. But for the longest time these structures were wrapped up in masonry, they were wrapped up in stone, they were hidden away, they were in the back rooms. Even when they were major structures.

So one of the major I suppose changes that modernism has wrought (a good word in the circumstances), is to bring the metal out in the open. I suppose the Pompidou centre would be a late and spectacular example of that.

James Grose: Articulation of structure is a fundamental tenant of architecture in any case. I mean you can read the Parthenon in that way. But in probably the last 40 or 50 years steel has become a device for articulation of structure. Whereas as you say before it was always covered up, and it's that shift in thinking that articulation of structure is a desirable commodity in architecture as opposed to concealing it, in fact it's a generational thing too I would suggest.

Alan Ogg: I think that's quite true, and certainly if you ally what you're saying to the recent developments in Australia, it's quite correct. But we mustn't lose sight of the fact that from the very earliest work using this material, those characteristics of light and lightness and big spans and clear articulation of structure and exposure of its structure were there from the very earliest. But they were produced by people who were engineers, fabricators, people who were just getting on with the job, they didn't have necessarily architectural pretensions. Any they were rather naive, you can see that in a lot of the decorative work.

For many of our older audience, steel buildings and corrugated iron will be associated with poverty, depression humpies, factory floors and makeshift shelters housing perhaps poor Aboriginal families. Do we still have a sense of making do with some of these materials?

James Grose: I think that's right, and there's a sense also - and this would horrify some listeners I guess - that for some buildings that Lindsay and Kerry Claire and certainly I have been working on recently too, we've clad them in unpainted fibro, to use old speak. But it's my view that the real essence of Australian architecture is in the exploration of what I would call materiality. It means that material (or materials) that can perform more than just a cosmetic or a somewhat narrative function, perform several layers of function. So it's quite correct that people think corrugated iron is a poor man's material, but in this sort of generational shift, a piece of corrugated metal is a beautiful thing. It's of its time completely, it's a fabricated material, a material that can be recycled. And in a structural sense, imagine you have this piece of paper and simply by putting ripples in it you give it strength... It's an extraordinary idea and it has a high degree of poetry just in that structural sense. Then in its galvanised or its zinc alumina state, it reflects the day and the quality of the light, it also has beautiful reflections in the moonlight. It's a wonderful modern material.

Alan Ogg: And the material's been used poetically by James and other architects in Australia and notice has been taken of this work, because it is significantly different to the manner in which Americans, Germans and the British have used the material. It's an interesting phenomenon.

Is there also something Australian (and Glenn Murcutt might be an example of this, he's probably made the best known use of this material internationally) in the notion of finding the poetry in the ordinary, finding the celebration of the commonplace?

Alan Ogg: Yes, I think that's an insightful observation, and in fact that's not only evident in the work of Murcutt and many other, it's also there in the early theories of post modernism in architecture. It was something that Venturi was very interested in. He didn't use the materials we're talking about, but he used this idea of taking the common place, the ordinary and of artfully and skillfully lifting it and elevating it into something else. It's difficult to do and when it is done, it's poetic by definition.

James Grose: It's also an attempt to demystify architecture and materials. In our practice, Nicola Bradley and I strove very hard to make materials or use materials that had inherent quality to them. In other words, you don't need to paste something on a concrete block, you try not to use a marble bench because a marble bench is a narrative that someone's applying, you know "I must have a marble bench because Betty's got a marble bench". But the choice of raw steel or raw concrete block or raw concrete is absolutely derived from this Australian characteristic of making buildings that are rudimentary. What gives them their power and their quality and their presence is the fact that the rudimentary has risen above all this sort of tic tac of painting surfaces and in a sense applying a pastiche - which happens in urban locations and one might hesitate to say that the phenomenon of the recent restaurant in Sydney is all about pastiche. Whereas architecture of rudimentary materials has nothing to do with pastiche, it has to do with presence and longevity and timelessness.

I want to get on to a few practical considerations with metal architecture. One thing that frightens some people about steel, especially in coastal areas, is that it might rust. Now I know that there are rust resistant products available, but rust is destructive which is one reason for not wanting it, so should we be seeing rust as inherently ugly or is there poetry in rust?

Alan Ogg: When we're talking about steel architecture within the industry, rust is a word which doesn't even exist. Corrosion is the word used and it is slightly softer... There are steels available which are metallurgically designed to rust or corrode and form a coating, a natural coating which protects the steel. It's an extraordinary material for which there were great hopes in the late 1960's and it's been used very well in a few isolated cases. But look, I think everyone has owned in their youth a car which we saw rust away in front of our eyes. It's a highly evocative word.

James Grose: But implicit in your comment is the fact that using steel as a material is actually a different state of mind from using timber or masonry, and it's the knowledge of connection that enables you to build buildings and certainly we have built some in very exposed conditions, I know Glenn Murcutt has and a number of architects right on the edge of the country, and it simply comes down to the knowledge of how to use the material and it won't rust.

People of course quite like the patina that you get on copper as it goes green, a very expensive material I understand. But there used to be a church with a copper coupe near where I lived in London and as a child I always used to look at that green and think "it's poisonous, if I were up there and licked it I would die". It always looked rather sinister to me.

I want to end with a specific example, which is the celebrated house James Grose built in 1990, perched on the Illawarra escarpment and clad in corrugated iron. The way it stands on its long steel legs has often led it to be likened to a praying mantis. But what interests me about it is that Wollongong has long been associated with the steel works and in fact the couple who commissioned the house made their living there. You would have thought that they wouldn't want to be reminded of heavy industry when they got home.

James Grose: On the contrary. There's a wonderful integration of their life there you see, working life, private life, their contentment. But seriously, the idea of using abstraction in architecture to make buildings belong to their place is one that's a long time ago used, and that's really all that's about. It's saying that Wollongong is marked, especially when you've got an aerial view of Wollongong, these long sight sheds that are made of steel and corrugated iron, fabulously beautiful things, and so why not make buildings that are to do with the built place. And really that's all that's doing, it's saying that you can have buildings of wonderful elegance that are industrially derived.