See the light. Clever use of glass can provide a spectacular extension to an otherwise plan home. Karen Hesse looks at house in Milltown and Portobello that are perfect examples

The Sunday Times (Ireland Home Section), December 1, 2002

There is house in New Orleans they call the Rising Sun. There's another one by the same name in Dublin 6, the antithesis of the property in the Animals' song that ruined poor boys, and a good example of making the most of what you've got.

The 1930s house in a mature estate in Milltown in typical of many three-bed semis in Ireland, built on a Victorian model, complete with red brick and rendered façade. Like many neighbours, the owners, Charles and Alice Sheehan, have converted the garage into living space. The extension continues to the full roof height and to all intents and purposes the house appears as if it has always been double-fronted.

To the front it looks like many others on the road. But that's where the similarities end. Behind the hall door there is a glimpse of light from the back of the house that is key to the transformation. "It's all about the light," says Gary Mongey of Box Architecture, Dublin 8, who was drafted to deliver the Sheehans' vision. They made their house their dream home and in the process scooped a design award for Box Architecture.

The couple knew what they wanted. Top of their wish list was a master bedroom and walk-in wardrobe. They also wanted a family room with access to the garden, an open-plan kitchen/dining area and a study and guest room.

The key component in Box projects is making the most of available light. Mongey says: "It is one factor that has the most influence on how people live and how rooms are used." He reworked most of the interior, adding 800sq m of floor space, to do this.

"We decided early on to stick with the traditional façade. It is easier to get planning permission for an extension that will be in keeping with a row of houses," he says.

Keeping the traditional front makes for a dramatic surprise when you cross the threshold. A low-maintenance but high-style black-tiled finish leads from the front door to the back of the house. Here a large family room embraces the garden through a bank of iroko teak, floor-to-ceiling windows and doors. To the back the extension is timber-framed and roofed in cooper, a slightly more pleasing than torch-on felt.

A lower ceiling here adds intimacy and allows for a long narrow window to flood light into the adjoining kitchen and dining room.

"We went for open-plan living downstairs and designed the rooms to catch as much of the rising sun as possible," says Mongey. This has worked so successfully that the owners now spend most of time in the kitchen and living room.

Upstairs, new and old blend seamlessly either side of central landing area. To the right, Box has created a dramatic, light-filled space to include the master bedroom. The design allows for a low ceiling in the walk-in wardrobe to facilitate a large room in the attic above. Light from five roof windows is filtered into the master bedroom through a panel of polycarbon, more typically used in conservatories.

Throughout the project, the couple stuck to their decision to get the most out of their €136,000 budget. "You can choose materials carefully to get the best out of the budget and spend money on permanent features while putting things like new kitchen units and landscaped gardens on hold," Mongey says.

Solid-oak flooring at €50 a sq m was used in the heavy-traffic living areas, and less expensive maple at €30 a sq m upstairs.

If you are considering a renovation it's worth bearing in mind that refurbishment will normally cost twice as much as a new-build. Depending on where you live, this can average €200 per sq m.