The care taken over the design of every aspect of this D6 house shows how good detailing can lift the spirits, writes Emma Cullinan.

We are all aware of the deity that is said to lurk within well designed and executed details and the Miesian edict rings true in this Dublin 6 house: the attention to detailing lifts the spirit.

This brief for this project, by Design Strategies, was to overhaul a three-storey, three-bedroom house, add in an extra bathroom and possibly another bedroom. The project also involved conservation work.

While beautiful detailing in itself can be pleasing; when it is just applied to perfecting standard elements to give a smooth, swish finish it offers neat and quiet satifaction but when it involves innovative, clever and creative solutions - built to perfection with conjoining elements lining up with each other - then you are into 'wow-factor' territory.

The first whoa factor greets you just inside the ground floor entrance to this house where an iroko tongue-and-groove box protrudes from the wall into the vast hallway. If you thought that you were in a conventional house then this would be read as a large cupboard but the nautical ironmongery on the door offers a clue: this box is actually a bathroom that floats off the floor.

It barely intrudes into the space but that is because it backs through the wall into the livingroom behind it where it appears as an elegant wall panel.

This means that the livingroom beside this ablution box can be used as a guest bedroom (with its almost en suite), a function that is aided by a matching tongue-and-groove cupboard for guests' apparel.

The bathroom is beautifully lined in grapestone from Antica and has a mosaic floor. This palette is repeated in the other two bathrooms in the house, along with sanitaryware bought from The Loft.

"It takes fantastic discipline on the clients' part, to allow us to use similar materials almost everywhere," says Jim Horan, head of Design Strategies. "But it helps to unite the house and is particularly important in a structure where contemporary elements are put into a period building. You have to respect the original as well as the 21st century and a continuity of materials very often solves this problem."

The result is that the three bathrooms give a flow of continuity throughout the house even though one is on the contemporary ground floor and the other two sit perched on the edge of very Victorian rooms.

On the top floor the bathroom used to be reached via a small flight of return steps. These were taken out to give the original staircase an appropriate grand finale: without the weedy extra tacked on.

The former entrance to the bathroom is now a wall and the new bathroom door is in the main bedroom accessed via some clever oak and walnut stairs - designed by the architects and made by Terry Doyle Woodcraft - which incorporate drawers (painted red inside for fun).

Its frameless glass balustrade is repeated through the house - both inside and out - in another example of design continuity.

The bathroom on the first-floor return is a new structure that owes its existence to period design. Often bathrooms were cantilevered off the backs of older houses and the architects have referred to this by pulling the tiny room out by a crucial 500cm to create a workable shower room.

Externally it is clad in standing-seam copper and has a slit window to one side that frames a nearby church spire. This side window offers privacy to and from the neighbours, which wouldn't have been possible with windows facing the garden.

Attention to detailing in the bathrooms includes shower-screen tops lining up with grouting lines and a shower handle that curves around to become a towel rail. The architects even discussed the possiblitity of mitreing the tiles with the tilers and - yes - these are now angled at their corners.

Apart from the bathrooms, the top two floors have remained intact - having been overhauled using best conservation practice, say the architects - because the house is a protected structure. This is why all of the contemporary elements are on the ground floor.

This used to be a dark two-room space dulled by a utility room on the back of the house which, apart from cutting out light, also severed the link between the interior and exterior.

The architects treated the ground floor as five interlinking spaces - family room, livingroom, kitchen, dining, garden - and worked to prevent any of them becoming useless and outclassed by the area beside it.

"One problem with adding extensions onto period houses is that you can end up with unusable room in the middle - it becomes a dead zone between other rooms," says Horan who is head of the architecture school at DIT Bolton Street and was recently made a professor.

The zones are connected by both the view - you can see the garden from the furthest room - and light levels. When you put a very bright extension onto a house, says Horan, you make the room beside it seem dark.

Here, the meeting point between the new and old parts of the plan is marked with a large glass panel in the ceiling. This area of the kitchen is in concrete, visable externally, and at its meeting point with the dining area, which is clad in copper, there is a thinner strip of glass in the ceiling. These ceiling apertures are designed to maintain even light levels: where the plan is deep the ceiling slit is wider and where the extension nears the large floor-to-ceiling windows to the outside, the glass panel is thinner.

Above the concrete part there is a deck accessed from a first floor livingroom or via steps from the garden. The glass panel - which, as with the detailing elsewhere, is flush with the deck - can be walked on for views of the kitchen below. While people get nervous about this the resident dogs display no such vitreous vertigo and glide across the glazing leaving muddy marks. The owner is considering fencing off the glass but there is something of a delight to be had in looking up from the kitchen and seeing furry tummies sliding about.

Outside the extension is seen as a series of boxes, with the copper clad dining area and the copper box that is the cantilevered bathroom relating to each other. The prepatinated copper is dark brown: "I resisted architectural cliché of going for green," says Horan, whose practice is working on a number of similar projects. Getting to this level of design and finish is up to the clients as well as the architects. In this case a lot was down to project architect Lotje Dujardin, from Belgium, who followed that well-trodden path of marrying an Irishman.

"Some of our projects have clients that will allow us to get to this level," says Horan. "It's important that they take on the notion of the completeness of the project and not just bits of it. Sometimes their personal preferences come in and they want to bring in things they had in the past - which may have worked in other houses but are not appropriate in the new project. If clients understand the overall concept it makes for a really good architecture."