Seamless combination


The Mill is a luxury housing development that saw a complex conversion combine new build with refurbishment of a historic hosiery factory. Richard Cooper of HSSP Architects spoke to Jack Wooler

A former hosiery mill dating back to 1889 has been restored into luxury apartments as part of a regenerative canalside development in Loughborough that restored original features obscured by a 1980s office conversion.

Designed by HSSP Architects, the Victorian building – once a historic factory that supplied garments to the Royal Family – heavily influenced the final project’s aesthetic. The team retained the building’s brick fabric while incorporating modern interventions and ecological additions.

From the exposed brickwork and detailing, to the original iron, oak and bow string beams, The Mill carefully weaves old elements with the sensitive additions of a new wing at one end of the site, wrapped around the mill’s once isolated chimney, and two new storeys at roof level.

Forming the lobby for the apartments at ground floor and an “iconic” entryway into the building, the retained and restored chimney has been as carefully blended with the new elements as all of the existing building’s features – but not without multiple design and engineering challenges at every stage.

Despite tackling these barriers, the first phase has now been finished successfully to great acclaim, and a further two phases are in the works. The project has so far delivered 76 luxury one and two bed apartments, alongside a residents gym, communal offices and parking, all in what has been described as a “groundbreaking regeneration project.”

A lucky position
Having worked with developer Solus Homes for a number of years, HSSP was approached directly when pharmaceutical giant 3M, whose UK office base previously occupied the site, put it on the market.

“Solus found themselves in a lucky position here,” says Richard Cooper, director at HSSP Architects and lead architect on the project. He tells ADF it was “a fantastic opportunity” for the project team, with a history “far too interesting to turn down.”

The mill originally created hosiery items such as stockings, and was located at the side of the canal for ease of movement of their goods across the UK. In the 1950s, it was converted into offices, in which 3M would take residence.

While the Victorian architecture was still very recognisable in the building’s form when the architects first visited the site, it had of course been reconfigured internally to offer the necessary office functions, and extended – though the extensions were ultimately demolished as part of HSSP’s scheme.

Cooper says the older features “were by far the most immediately attractive elements from the outset,” the architects appreciating the cast iron columns, exposed timber and the industrial aesthetic, which all “lent themselves very easily” to the functions being served by the practice’s design.

“The look was already there,” he says, “it had just been hidden by its incarnation as an office.”

Ticking all the boxes
The architects began by carrying out a standard site analysis, looking at the focal, and entry, points of the project – which were largely based around the chimney – and how people would use and perceive the building.

Though the retention of The Mill’s chimney was key, Cooper says its restoration “was a fairly contentious point in the early days, as the developers thought it would be more of a risk than a feature.”

However, the team “slowly convinced everybody, and in the end it worked very successfully,” says the architect. Once a more complete plan was produced, the planners were reportedly “won over very quickly.”

The project “ticked all the boxes,” he adds, it being a brownfield site, and fulfilling both the regeneration and placemaking needs of the local authority.

“Because of this, the planners and council were extremely supportive,” says Cooper. “We engaged with them all early in the process, and everyone was very helpful.”

He adds that it has already proven to have kick-started the regeneration the local authority was hoping for.

Free reign
Cooper says the team had “fairly free reign” when it came to the design process – the client’s brief dictating mainly on the building’s use and how many units were needed to make it viable.

The waterside provided another key design inspiration, says the architect, the team being “keen to build on its language, along with the industrial elements of the mill.” Cooper says that the tall glazed roof extension with exposed steel framework was intended to “evoke this dialogue between water and industry.”

One of the key elements of the process here was to combine this design language with that of the building’s historic nature, and to reinforce the deep reveals of the brickwork in the new build elements to make it look “part of the same family.”

“On the new wing,” he explains, “we went to quite a lot of trouble to get deep reveals in the cladding to hark back to the existing structure,” something that the planners were also reportedly keen on.

“Traditional buildings’ deep brick reveals are clearly something that’s missed,” he adds, with modern buildings tending to have much shallower depths.

On the inside, the team worked very closely with the interior designers Kick Associates to continue these themes and “bring the building back to life,” ensuring a continuation of the same design values as its exterior, to create a holistic overall effect.

The project’s architect tells me that the whole design process had to be somewhat “fluid” here, as when removing the 80s office additions such as the suspended ceilings, ever more elements of the building’s history were revealed – to subsequently be exploited in the creation of the final design. This includes the original cast iron columns, which being structural could not be relocated or removed, and instead have been embraced within the apartments and communal areas.

The Mill involved many challenges in its construction process to realise these designs, from the ground all the way up to the new addition. “Starting from the bottom,” says Cooper, the existing building’s “massive, deep foundations” were amply capable of supporting the “fairly small and lightweight” new build element. As such, the team managed the project without piling, just using traditional insitu poured concrete.

He describes how the existing brick frame starts off very thick at the bottom, and gradually gets thinner toward the upper stories. Structures were typically constructed this way in the pre-steel era, masonry and cast iron columns having to take the vast bulk of the buildings’ loads.

The existing brickwork of the Mill was “in pretty good condition,” the architect tells ADF, and as such there weren’t many necessary remedial works – only “a few bits” of pointing and repairs to sills.

When it came to the added brickwork elements in the new wing, however – which were also constructed as load-bearing masonry with concrete planks to fit with the existing structure – Cooper says it took some “fairly lengthy” technical analysis to achieve LABC accreditation.

Moving up to the roof extension, sitting above both the new build and restored sections, the team turned to Fusion Building Systems to create a structure lightweight enough to be supported by the brickwork.

Cooper explains that these additions were necessary to meet the client’s brief for an increased number of homes in the project’s footprint. The retained chimney previously stood alone together with “a kind of boiler house,” so the architects enacted the wing extension through this new linking block that wraps around it, and which subsequently “leads it all back to the mill.”

Then, in order to achieve the two new floors added above all this, the team had to remove the pitched slate roof from the existing brick portion, as well as undertake the removal of some “insensitive additions and links” made in the past during the building’s conversion to office space.

“The developer did a really good job of sourcing all these materials to recreate the key details,” the architect adds.

Structural stress
When it came to structural challenges around adding the new floors above the existing building, “there was a lot of technical work necessary to get it right,” Cooper explains.

A bespoke, “highly complex” metal grill system was used to connect the base of the new floors to the existing building and fully support the ‘fusion frame’ system at the point of transition.

The team was surprised to find that in stripping out the existing brickwork structure, it was out of level by around 300 mm across the length of the building.

“Nothing’s square when you’re dealing with these old buildings,” says Cooper.

“It was quite a headache, trying to deal with one system which needs to be made with precision in a factory, and then trying to insert it into something which has been hand built in the Victorian era.”

The architect tells me it took “a huge amount” of setting out, modelling and resurveying to achieve this connection.

Live, work and play
Having achieved this complex hybrid structure, Cooper says that the client wanted to do “something different” when it came to the scheme’s end use, and intended to “set the benchmark for regeneration” in so doing.

“It’s not the standard conversion of a building, where they just thought about how many flats they could get in and how cheaply they could do it,” he explains. “It’s a placemaking project, and we’ve really paid attention to how we could create a community here.”

As such, the architects followed a “live, work and play” ethos when designing the placemaking aspect of the development.

Embodying this idea, there is a gym, a communal work at home office space where people can mix and “not feel isolated working in their own apartment,” and a communal garden space. This includes table tennis tables and street furniture – intended to “encourage people to form a community.”

Being alongside a canal, the development also naturally offers the leisure opportunities of cycling and walking down the waterside.

“Especially in a time of lockdown, exercise is vital for mental health,” says Cooper, “and there’s no better incentive to get outdoors than having the perfect spot for it just outside your front door.”

A greener build
In terms of low energy technologies, the architect admits the project may not be a “model of environmentalism,” however multiple elements helped achieve a greener result.

Green roofs were one such addition – the lead architect reports these were welcomed by planners. Further aiding biodiversity, bat and swift boxes were included following stringent ecology surveys.

The project also features solar PVs, but Cooper believes that the real sustainability at The Mill is found in how it reuses a substantial existing building: “we’re not losing all that embodied carbon that went into its construction.”

He summarises, “We believe that the reuse and adapt method is far better than building something new with flash technology added.”

With brick production having significant amounts of embodied carbon, “it would have been a crying shame to have knocked it down and started again,” he says.

Problem solvers
The first phase now complete, the team has started work on the further two phases, phase two starting in August this year and due for completion in Spring 2022, and phase three expected to begin in the middle of 2021.

Cooper looks back to the “numerous” challenges within the first phase, but says that, “as an architect, that’s basically your day job; coming up with solutions to problems is just what we do.”

Despite this, he still cites the matching up of the new frame with the restored building as “a huge task,” one that couldn’t have been achieved without high levels of collaboration between the project’s stakeholders.

The planners were “delighted” with the end result, he says, as were the developers, having managed to sell all units within the development off plan.

In what is a hearteningly positive coda to a challenging project, its architect says “we’ve only heard positive feedback so far – people are so proud to have been involved, especially ourselves.”