A student at Bolton Street got a practical lesson in architecture when her family commissioned a Modernist extension with memories of Mies, writes Emma Cullinan

WHEN THE owners of this west Dublin house commissioned an architect to design them an extension, they were not only improving their own home but also offering their daughter a valuable lesson.

Ruth Condren, who is in her fourth year of studying architecture at DIT Bolton Street, could now put the theory into practice. She sat in on consultations with architect Ronan Rose-Roberts from the start and once the structure began to go up, "suddenly the structures lectures started to make sense. I understood the principle from what I had been learning at college but it really began making sense".

She also got an insight into the process from the client's point of view: "Especially in your own house, you are a bit blinkered by the way things are. We had been living here for 16 years and you are so used to the way you use the space it took someone like Ronan to come in and open our eyes to different ways of looking at our own home.

"It was also interesting seeing the process Ronan went through and how the design developed from concept to built reality."

The first thing that strikes you on seeing the finished garden room, to the rear of a two-storey pitched and pebbled dashed house, is its similarity to architect Mies van der Rohe's 1951 Farnsworth house, in Illinois. That floating, glass, rectangular building is both a distillation and paradigm of the International style.

Yet Rose-Roberts did not set out to create such a thing. "I design buildings from the inside out, starting with what the client wants," he says.

The Dublin clients loved their garden, which they had designed and planted, but access to their former cold garden room sent them round a twist: it was reached from the rear kitchen, via a utility room and round into the conservatory.

The brief, then, was for an accessible room from which to enjoy the garden but which would not take up too much of it; instead fitting onto the footprint of the former conservatory and utility.

The clients are also interested in art and, combining the two loves, discussions led to the idea of treating the garden as a painting and seeing it through a triptych created by three large glass panes, and broken by three internal columns.

But the first design Rose-Roberts sketched out, and modelled in Plasticine, for the clients was an asymmetrical angular structure with glass walls facing in different directions.

Further discussions led the shape back to right angles, still with lots of glass, and a request for a canopy. "I drew the elevation and we were looking at this horizontal structure, with its glass panes, and I saw the similarity to Farnsworth," says Rose-Roberts. "I didn't want to pretend that it was not that or for the Mies building to be the elephant in the room, so I said: 'This is similar to a classic piece of architecture'. Ruth knew about it straight away, and we had all talked a lot about Modern architecture before, but after that we left it aside and concentrated on the design detail and the idea of simplifying it."

Once this design had been reached, Rose-Roberts wanted to give it finesse by honing the details: if you are going to reference an iconic building - however loosely - it pays to do it well. Just as it is possible to pastiche classical buildings it is possible to do tawdry copies of Modern ones (or classical Modernist buildings, if you like!)

"I sat in the office looking at how to make it all work. I wanted the façade to be like a sliced edge and I had to make that sheer face work, through the details."

Ways of paring back the building also included integrating the canopy into the steel-frame structure, as a continuation of the roof, and rainwater is sent unseen down through the internal steel columns - to save cluttering that cliff-edge elevation with downpipes. The issue of connecting a glassy and white rectangular building to a pitched and rendered structure was resolved by stepping the new part away from the house and indenting the glass to create a three-sided square in which to slot plants. Large expanses of glass come with issues of solar gain and cold-weather pain.

The surrounding vegetation and orientation of the extension saves it from excessive solar gain. The plethora of deciduous trees shades the building in the summer while the south-east aspect of the main façade attracts early morning heat from the sun which then heads south behind trees and any beams filtering through the leaves and branches hit the short, side elevation of the extension. Each end of the extension opens up to allow cross ventilation.

Nature was also addressed in the use of sustainable materials. A structural timber frame was mooted for this highly insulated extension but the engineer said that wood would be too flexible to cope with the large cantilever so they opted for steel.

Rose-Roberts wanted to avoid too much pvc in the white roof and found an environmentally-friendly waterproof membrane catchily called Thermaplan T, from Bauder, a company better known for its green roofs.

The space is heated through grilles in the floor, at the edges, and above these are fittings for curtains, but the clients have decided against them, which some may feel would leave them open to scrutiny. Indeed, Mies fell out with his client Dr Edith Farnsworth at Farnsworth House (a building that also has heating in the floor, protection by trees and cross-ventilation) because the building went over budget and also, she said it was not possible to live in such a structure. Mies' argument was that the house was meant to be a weekend retreat rather than a family home.

Many would feel nervous about being exposed in a glass house but that depends on the type of person you are; Irish architect Niall McLaughlin designed a glassy house in England for one person who loves it and told me that if people really want to gaze at his middle-aged body, then good luck to them.

The other crucial aspect to glass structures is their surroundings, and this Dublin house is well sheltered by fences, trees and shrubbery. And it is that verdure which explains the appeal of glass houses: it is not, self-consciously, about who is looking in but, instead, what you are looking out at.

When architects leave, clients adapt to the space in their own way (unless you were a client of Frank Lloyd Wright who would drop in unexpectedly to check that everything was as he left it) and in this Dublin home they sit in the room without the internal lights on and instead soak up the atmosphere of the garden lighting which includes two beams ascending from the patio, that work as virtual columns at the end of the cantilever.

While the Farnsworth reference was dropped early on in design discussions, the clients picked up the Mies connection when they chose furniture, and now the extension has Mies' Brno chairs, and elsewhere in the house there are Barcelona chairs and (while they were shopping at Design Classics Direct) they picked up some Le Corbusier armchairs too. The clients have also been to visit Farnsworth.

"When I first met them they had nothing Modern in their house at all," says Rose-Roberts, who would have been equally happy if they had put antique furniture into the bright, white space, something he saw used to good effect in the film 2001 Space Odyssey. "But now the house is dramatically different and shows how their taste has changed."

It is strange seeing something so close to a design icon, and we have also become a bit wary of white boxes, but this extension really works: the way it flows out from the kitchen, sits lightly in the garden, has a sheltered outdoor area, and how each connection between materials and changes of direction has been carefully considered. (I have tried to resist bringing up Mies' oft-used quote about the place of God re: details but Rose-Roberts has certainly kept the faith in this project).

The existing house was built recently - and is a loose twist on Classicism - while the extension is a tighter twist on Modernism, and it shows how we have become more open to different styles.