No house of straw: Sarah Wigglesworth's eco-home, 20 years on

“I’m a real believer in trying things,” says the architect Sarah Wigglesworth. “That’s how you learn. Taking risks is really important. I’m interested in the things that give a kind of joy and maybe disrupt things. I am interested in pushing boundaries. Anything that does that is good.”

Wigglesworth – who was appointed MBE in 2004 and became the first woman to receive the Royal Designer for Industry award for architecture in 2012 – is describing herself, but she could easily be talking about how she designed her home in north London. 9/10 Stock Orchard Street is the multi-award-winning live/work space of Wigglesworth and her partner, Jeremy Till. Built 20 years ago, the “straw bale house”, as it was invariably called, instigated a debate about the aesthetics of eco-architecture. “At that time,” Wigglesworth recalls, “the green movement was about dropping out to north Wales or somewhere and building something quite vernacular with your hands. We wanted to make an urbane version of that, in an urban setting.”

As a practice, Sarah Wigglesworth Architects (SWA) has since become renowned for its life-enhancing public buildings, including social housing, schools and community centres. However, during the two-year Stock Orchard Street build, the practice almost folded, so all-consuming was the work. The couple had sold their home and, for nine months, Wigglesworth lived on-site in a caravan. (“In the spring and summer, it felt like a holiday camp, but by winter it was damp and miserable.”) Till – who is now head of Central St Martins and pro vice-chancellor of University of the Arts London – spent his weeks up north as the head of the school of architecture at Sheffield University. Wigglesworth was appointed to Sheffield at the same time (she was a professor of architecture there until 2016) but took a sabbatical to concentrate on the project.

The L-shaped building is situated at the end of a short residential road. On one side is a row of semi-detached, Victorian villas, on the other a busy railway track that slopes towards King’s Cross. The couple bought the plot at auction in the mid-90s. At the time, it was a working forge: part-gas furnace, part-junkyard. It wasn’t until the site was cleared that they realised just how large it was.

At the same time, they had regular visits from a film crew: their straw bale house featured in the first series of Grand Designs. Ten minutes into that episode, Wigglesworth tells presenter Kevin McCloud: “In a way, I don’t really care what the outcome is: I just want to build it.” She feels now that the technical aspects of the build weren’t fully showcased; that she and Till were “actors in a drama”. “The production company understood TV, but they weren’t familiar with the complexities of getting a building out of the ground,” she says. The project was delayed, so the producers introduced a distracting subplot in which McCloud builds his own rural, straw bale cabin. That said, there have since been two “revisits” and 9/10 Stock Orchard Street remains “one of Kevin’s favourites”.

When it was finished, the editor of the Architectural Review, Peter Davey, called the straw-bale house “the most sexy and witty building I have seen for years”. He predicted that it “will be seen as one of the most gallant experiments in eco-architecture of our age”. He was right.

To enter 9/10 Stock Orchard Street, you pass through a fence of woven willow and galvanised steel. This opens on to a series of vertical gabions (“cages” filled with lumps of recycled concrete). These piers support the office wing, which is clad on one wall with weathered sandbags, filled with cement and lime, which absorb the rumble from the adjacent railway line (the inspiration was a photo of Swansea’s plate-glass-windowed Kardomah coffee house during the blitz). Above the office door, the facade is swaddled in silicone-faced fibreglass – a kind of wipe-clean quilt, which is “buttoned” to the structure of the building.

Wigglesworth’s home is connected to the office via a double-height conference/dining room. The dining table is pivotal for Wigglesworth. Her drawing, “The Disorder of the Dining Table”, is an exploration of order and control in architecture. It depicts three dining tables in various states of use: before a dinner party, with chairs tucked in and places set; during, a scribble of movement; and after, a mess of crumpled napkins and abandoned plates. Wigglesworth calls the drawing a “post-rationalisation of the idea that we were fighting very hard against: this concept of the perfect product”. For Wigglesworth, the rituals of eating are analogous to the rituals of domestic life. “We were designing this in the mid-to-late 90s, when sheer glass and very minimal interiors were the sort of gold standard of architectural homes. But we wanted the mess, we wanted the dirt – we wanted our home to be able to accept all the spills of everyday life.”

The conference/dining room connects to the living space via a sliding door made from heavily patterned douglas fir. The reveal is dramatic – like a sheet falling off a sculpture. The space Wigglesworth has created for the scribbles and spills of everyday life is full of light, texture and colour – but mostly, it is full of ideas.

The steel-and-timber structure of the living and sleeping quarters has been insulated with 550 barley straw bales. These are covered by sheets of corrugated, galvanised steel on the outside, and rendered with lime plaster on the inside. On one facade, the steel has been replaced by sheets of clear polycarbonate, revealing a glimpse of the insulative straw bales, which, 20 years on, are as golden as the day they were first laid. (Unlike the polycarbonate sheets, which are cracked and taped together in parts.)

A “summer ventilation strategy” has also been incorporated into the design. On warm days, a series of louvres in the lobby can be opened. These draw cool air into the building, while hot air is pulled out through another louvre system at the top of a five-storey tower, the couples’ library and creative “eyrie”. The larder – a central area of cool that looks like a giant anthill – separates the living space from the kitchen. It functions in much the same way, with vents at the top and bottom. “One of the things we were unpacking was this idea about re-learning technologies,” says Wigglesworth. “Of course, now we have fridges, but there are ways of keeping food cool without recourse to energy.”

Wigglesworth was thinking about gender when she decided to make a combined conference and dining room. “I have always been really interested in the idea of ‘women’s work’ and what it means to be the worker – to be the proprietress of an office at the same time as being the homeowner and the homemaker. To my mind, there’s very little distinction […] Everything is happening at the same time, even in your brain.”

This year, SWA marked its 25th anniversary by hosting an exhibition at the Anise gallery in London. For the show, each studio member presented a piece of work made in response to some of SWA’s most memorable projects. For Wigglesworth, the exhibition represented a way of “stepping back” and “democratically reflecting” upon the themes in architecture during those years.

Gender inequality in architecture is one of those recurrent themes. In the mid-90s, Wigglesworth co-curated an exhibition, symposium and accompanying book called Desiring Practices: Architecture, Gender and the Interdisciplinary. Twenty five years later, the issue “has come round again”. Today, Wigglesworth is a member of Part W, an action group of women “calling out gender discrimination in an industry that routinely excludes”. Wigglesworth says: “I sometimes go to meetings with a younger male colleague, in which I will ask the questions, and the person I’m addressing will answer my young, male colleague. I find that almost unbelievable, but that still happens.”

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For their first campaign, Part W drew attention to the fact that, since 1848, the Riba Royal Gold Medal had been awarded to just one woman in her own right. By crowd-sourcing an alternative list of women who have been overlooked for the medal, they highlighted how female architects have been routinely underacknowledged. This year’s award went to Part W’s co-founders: Grafton Architects. The organisation is also interested in ensuring women’s viewpoints are given equal representation in education, histories of architecture and speaking platforms (“there are too many ‘manels’”). “For too long, bodies that are responsible for creating the discourse, and that represent the industry, have not paid enough attention to doing this,” says Wigglesworth.

In the 20 years since 9/10 Stock Orchard Street was built, the green movement has evolved. Building regulations have changed and techniques for analysing energy efficiency have improved. Wigglesworth’s timber windows had warped and part of the roof will not stop leaking. (“I shouldn’t tell you that, should I? No architect’s roof ever leaks.”) It was time for a renovation.

At the beginning of last year, SWA commissioned the energy consultancy Enhabit to assess the building’s performance, including thermal imaging and airtightness tests. They pored over energy bills, measured the U-values of the building fabric (how effectively their sandbags, steel and straw act as insulators), and fed the data into Passivhaus software to determine the energy efficiency of the building. The research highlighted areas that needed rethinking. For Wigglesworth, the work that ensued is a continuation of their initial concept: “It is part of sustainability, this idea that buildings are cherished. Your home should be treated as if it were a part of your body – which in a way, it is. It is a kind of bigger expression of yourself, and you need to look after it.”

Now they have reinsulated and re-rendered the large glass wall in the living space and the “undercroft” (the area underneath the raised, open-plan living space). The warped timber windows have been replaced and a section of polycarbonate roof has been replaced with rooflights and blackout blinds. And, “after much discussion”, a new boiler has been fitted. “We were wondering if we should put an air-source heat pump in,” says Wigglesworth. “But we decided not to on the basis that, by the time this needs replacing in 20 years, the technology will have improved massively.” (Already, she is thinking of the next renovation.)

They have removed a wall between the tower and the living area, so losing a redundant corridor. The floor has been replaced with engineered, oiled oak, the window frames painted in either green or blue, and the walls and woodwork in gloriously off-kilter shades of coral pink and pale lilac (“I’m not very good at colour,” she confides. “I find it really, really hard.”)

At the end of that episode of Grand Designs, Wigglesworth tells McCloud: “I’ve always seen this house as something of a plaything for us architects […] You can test an idea on paper ,” she says, “but the proof of the thing is in the building of it, and the experiencing of it and the living of that life.”

At the age of 62, Wigglesworth has – alongside improving energy efficiency – made the building more age-friendly. The composting toilet has been decommissioned (“I don’t want to be maintaining that when I’m 80”), helping create room for a self-contained annex on the ground floor, which may, some day, be lived in by a carer. In the kitchen, gas rings have been replaced with an induction hob and an eye-level oven. Accessible drawers have been installed. There are even handrails on the bath. Wwill she be OK to use the five-storey tower, I ask, as we ascend the bright red, book-lined staircase. “As a musculoskeletal organism, you need to keep moving,” is her pragmatic response.