A hidden roof terrace and minimal wood-lined interiors are among the features that Cathie Curran and O'Sullivan Skoufoglou Architects have added in an overhaul of this north London house.

Aptly named North London House, the renovation and extension added an attic bedroom and a ground floor studio flat to the home, alongside a private terrace that is connected to the kitchen and dining room on the first floor.

It was designed by Curran and O'Sullivan Skoufoglou Architects to provide the client, a family with a young son, with plenty of space to entertain guests, while also meeting their changing needs over time.

"As with many London houses, the primary brief requirement was to maximise the floor area," said Curran and Amalia Skoufoglou, co-founder of O'Sullivan Skoufoglou Architects.

"The client brief included a studio which could be used by a guest or family member as part of the household or let as a fully independent unit," the pair told Dezeen. "Futureproofing was a key concern – the studio may equally be required for use by a carer or an elderly person unable to manage stairs."

In total, Curran and O'Sullivan Skoufoglou Architects' intervention has given the four-storey North London House with an extra 26-square-metres of internal space.

These spaces are unified by their light and pared-back finishes that the team has designed to "complement the architectural intent".

"In this instance the palette was condensed in order to reduce surface disruption and maximise the feeling of space in the new elements," explained Curran and Skoufoglou.

North London House's new rear extension, which contains the studio, is slotted into the plot where the home's high-walled garden once was positioned.

As this blocked the existing ground floor windows, the team punctured the extension with a light-brick courtyard on one side that mean natural light can still enter.

Inside, the studio is lined with white-painted masonry and flush plywood cabinets. These bright finishes are designed to help maximise light inside, which enters through a strip skylight on one side.

To replace the garden that was lost to the rear extension, an 18-square-metre roof terrace is positioned on top of the studio.

Curran and O'Sullivan Skoufoglou Architects have lined this terrace with a series of solid-ash posts that support opaque glazing in order to retain privacy from the windows of the neighbouring houses.

The terrace is accessed by home's new kitchen and dining room, which Curran and O'Sullivan Skoufoglou Architects relocated to the first floor to sit in line with the outdoor space.

Forming the heart of the renovation, this layout is designed to maximise space to host as "entertaining friends and family was another major consideration" in the client brief.

The finishes in the kitchen and dining room are bolder than the rest of the house, fitted with a mix of materials like marble and brass, as well as furniture pieces including a walnut table by Pinch.

Its focal point is a dark, handmade and hand-stained kitchen unit that is positioned next to the door to the terrace.

At roof level, the house has a new loft bedroom with an adjoining shower-room. This is designed specifically for the client's child to meet his needs as he grows older.

Here, plywood is used as the single material for the walls, ceiling and floor, concealing flush plywood storage spaces that include a pull-down bed, and broken only by a large dormer window.

O'Sullivan Skoufoglou Architects is a London architecture studio founded in 2016 by Jody O’Sullivan and Amalia Skoufoglou.

Other projects by the firm include the interior design of the RÖ Skin shop in Lincolnshire and an extension of a typical terraced home in northwest London with a new timber-lined room that opens onto a brick-paved garden.

Photography is by Ståle Eriksen.