Bright ideas throw light on the domestic extension

While domestic extensions yield welcome additional space, they can also create their own problems when it comes to bringing light into an even deeper plan. In the following pages, we look at three Victorian house projects that tackle overhead light with aplomb. Overcast House, by Office S&M, makes a virtue of north light by using a saw tooth roof to provide just the right conditions for the colour consultant client. In contrast, the two other projects give the skylights starring roles. Another side return project, Matthew Giles Architects’ Hannington Road, floods the new double height space with light with the help of extensive overhead light.  And at Umfreville Road, DHaus uses dramatic skylights to bring light into the heart of the plan and, in doing so, transforms the experience of the apartment.

Umfreville Road, London by DHaus

‘It makes you feel like you’re flying through the sky – it’s an amazing feeling,’ says DHaus co-founder David Ben-Grunberg of the practice’s transformation of a dark maisonette into a light-filled triplex in north London.

Before, a gloomy staircase was the initial impression of the first and second floor apartment, but no longer, thanks to the addition of an ‘up-and-over’ frameless skylight to drench the staircase in light. This addressed the biggest challenge of the refurbishment – how to bring light into the core.

The practice worked with 1st Folding Sliding Doors to create the 1.6m by 1.8m skylight, which combines in an L-shape with a 1.6m by 1m side panel to accommodate light both from above and the side – bringing, says Ben-Grunberg, a magical dimension to the experience of ascending the staircase. 

The double-glazed units are set into a concealed anodised aluminium frame to maximise the impact of the sky. 

The effect of the skylight is enhanced by the open lattice staircase. For this, DHaus drew inspiration from the work of architect Taro Tsuruta, a friend of the client, to create a bespoke plywood design by Materialise Creative Design using CNC fabrication, with perforations that allow light to permeate down. The underside is curved to give a softly contoured effect.

‘The stair is an investment piece at about £1000 a tread and was one of the things [the client] wanted to spend money on. Not only is it a nice statement piece but it’s practical for bringing the light through,’ says Ben-Grunberg.

A 2m by 3m inner roof terrace has cunningly been inserted to the side of the rooflight  one of the first upper terraces in the area, he adds.

The other main move was the loft conversion. For this, a dormer roof extension was enabled by structural reinforcements of extra beams and posts. In here, an unusual, giant triangular skylight with a 450mm reveal gives the new bedroom space an eye-catching character from both inside and out. 

Measuring 3m by 2.2m by 2.1m and again created by 1st Folding Sliding Doors, which had not previously tackled such an unorthodox shape, the metal-framed skylight is manufactured in double-glazed glass with low E argon gas. Rather than sitting flush in the roof, it projects by 150mm for better waterproofing by enabling rainwater to drain around the windows and down. 

The concealed frame puts the focus on the view of the sky – it is, says Ben-Grunberg, ‘like going into a spaceship.’

Structural engineer Michael Alexander Engineering

Selected suppliers 1st Folding Sliding Doors (skylight); Materialise Creative Design (staircase)

Hannington Rd, London by Matthew Giles Architects

Enclosing adjacent garden space is a classic strategy for many a kitchen overhaul. But making your neighbour’s party  wall the star interior design feature is a more unusual move, carried out with aplomb by Matthew Giles Architects with the help of a 5.4m by 2m skylight.

The new space is part of an extensive overhaul of a Victorian townhouse for a young professional couple, in Clapham Old Town in south west London. The architect decided to enclose the side return at second rather than first floor level, creating a double-height space on one side of the kitchen-diner and replacing a low-quality lean-to.

‘You get this lovely space, glazed above, full of natural light – it’s quite dramatic and different,’ says Giles, adding that the architect had ‘lucked-out’ with the presence of the distinctive Victorian brick wall, which had at some point acquired dashes of white paint. The bathroom and study windows both look onto this space at first floor level.

All the wall needed, he says, was sealing, plus the addition of the huge skylight, which brings the light down to play on the wall. The rear facade now has new steel-framed Crittall glazed doors and windows.

The bespoke skylight was created by L2i Aluminium, which the architect had collaborated with on several previous projects. After discussions about panel sizes, installation and detailing of the junctions between frames and the main building fabric, it was designed to create the roof light in four double-glazed panels, each 1.3m wide and framed in powder-coated aluminium. The most complicated part was panel nearest to the rear wall, which opens as a vent via a switch-operated mechanism as part of the natural ventilation strategy. 

Enclosing the wall space was part of a desire to blur the boundaries between the interior and exterior – previously, the presence of a toilet at the back of the house had blocked views of the garden from the kitchen. 

This inside-outside theme continues at the rear of the house, where the kitchen opens onto an ‘outdoor lounge’, a sunken patio area with its own sink to one side and above, a pergola arrangement of timber joists – the hope is that these may one day support a vine.

As well as the kitchen intervention, the architect reorganised the ground and first floors to create a four bedroom family house, with a study overlooking the newly-created ­double-height space. At the end of the garden is a new gym. 

Matthew Giles Architects is currently working on 24 ­further residential projects throughout the capital.

Civil/structural engineer Michael Barclay Partnership 

Contractor  Lucas Construction

Selected suppliers L2i Aluminium (aluminium rooflight); Fabco Sanctuary (Crittall glazing)

Overcast House by Office S&M

When Office S&M designed a small, single-storey rear kitchen extension to a house in north London, it wasn’t merely a question of getting in enough light, but getting in the right sort of light too. This was crucial given that one half of the client couple, Keiko Cummings, a colour consultant, would be using the new space for meetings with her own clients so needed a consistent quality of light, which had been difficult to achieve at the front of the house where she previously worked.

As well as dealing with the light, the architect needed to deliver a kitchen space big enough to accommodate 10 people around a table, whether for Keiko’s consultations or socialising. Permitted development would have allowed a 3m rear extension, but by taking in the side return, Office S&M’s design required just a 1.5m rear extension to increase space from 94m² to 114m². 

The solution was a series of saw-tooth rooflights, an approach common to studio or gallery spaces but more unusual in a home. The row of three rooflights delivers indirect north light to the enclosed side return, with a further, flat roof light to the rear, where it is shielded by the back wall of the main house. To neutralise the cold light coming through the roof, the wall was painted gold.  

‘Sawtooths were the best way of achieving even lighting, says Office S&M partner Hugh McEwen. We looked at some more shaped rooflights but they’d cast shadows and pools of light.’

Office S&M used Velfac V200i fixed windows measuring 1268mm by 432mm with poly­ester powder-coated aluminium frames in tandem with a bespoke build-up. This was designed to be as thin as possible in order to minimise the overall height of the roof, which rises to 770mm. The solution was a timber roof frame with Kingspan insulation on top and between the beams to give a hybrid between a warm and cold roof.

It was decided to continue the timber to ­create the structure for the whole extension, with rear leaf of self-supporting cast concrete blockwork. Created in collaboration with Mortise Concrete, the pigmented blocks are scalloped to act as ‘shadow catchers’. A prominent hopper is celebrated in contrasting dark green, and marks the transition to the former side-return.

On entering the extended kitchen, visitors are funnelled away from the cooking area with the help of an angled wall that conceals a new WC, and the orientation of the flooring, which follows the same direction. The new space has the flexibility to position the table at the rear or the side. The clients are currently using the new area beneath the rooflights for their morning yoga.

 ‘You don’t have to build the biggest space to have quality of space – you can create really wonderful spaces that are compact,’ says McEwen. 

Engineer Foster Structures

Contractor YG Builders

Selected suppliers Velfac (rooflights), Kingspan (insulation)