Mercato Metropolitano Ilford opened last July on Chadwick Road in the London Borough of Redbridge, promising business opportunities, cultural exchange and 100 new jobs all with expectations the Elizabeth Line would help bring an influx of people to the area. As of February this year, only an ice cream kiosk remains of its former 20-plus traders and less than a quarter of the food halls floor space is open to the public and at reduced opening hours. This is most likely a symptom of a gloomy post-Christmas blip, but it is just the latest of many challenges that the market has seen on its seven-year stop-start ride from conception to completion. This is not a story of a failing entrepreneurial endeavour but one of perseverance and about attempts to fulfil a promise to one of the most diverse communities in the country.The low-tech community food markets journey began in 2018 as part of Redbridge Councils Spark Ilford regeneration project for the creation of a cultural quarter, funded through the Mayor of Londons Good Growth Fund. An existing surface car park earmarked for housing was identified as one of three council sites for five years of meanwhile use, along with Redbridge Town Hall. Sustainable food and community market provider Mercato Metropolitano was introduced to Redbridge Council following the successful opening of its flagship market at Elephant and Castle, boasting a sustainable and community manifesto that aligned with Redbridges vision of an Ilford for all.AdvertisementIn 2018, Redbridge ran a day-long charrette-style competition for the pop-up market-cum-cultural hub commission. Four teams including Asif Khan, Jestico + Whiles with Goldfinger Factory and Greig were contenders, and Interrobang was chosen. Interrobang was at the time an architecture and engineering practice, founded in 2015 by Smith Mordak within natural materials-specialist engineer Webb Yates. However, it was wound up in 2020 when Mordak, who is now chief executive of the UK Green Building Council, moved to Buro Happold to become a director of sustainability and physics.Interrobang was the laziest, jokes Marc Clark, regeneration programme manager at Redbridge, recalling that the winning team put together just two pages during the day-long charrette in the neighbouring town hall. The process was intended to give emerging and smaller design practices a chance to bid for mayoral-supported projects, as well as to inform the brief, adds Clark. However, it had nailed down exactly what client Mercato was looking for: ideas for a covered commercial and community facility featuring a rooftop hydroponic farm and education space, useable for community events, music, urban farming and studio space, and meeting Mercatos own ambitions for an element of self-sufficiency.Clark speaks positively about the charrette, saying it set up a good working relationship from the outset. We werent the direct client, but everyone wanted it to succeed, he adds. Unusual at the time for Greater London Authority-funded projects, the process of a charrette was selected to encourage the client to engage with the ideas of the design teams, rather than focusing primarily on fees.The designs starting point was the car park that is used to being rained on, says Webb Yates associate Dan Cole, recalling that the projects core philosophy was to return the site undamaged at the end of the lease period, leaving the site free from buried structures that would need to be removed. Initial proposals were for a hyper-flexible timber structure with demountable frame that could be reconfigured or relocated to other sites. Circular design principles were central, and the project would be detailed to eliminate material wastage through maintenance.AdvertisementSo, no foundations, just timber feet, he adds, the idea being that these feet would sit atop the car park site, spreading the structures load with vertical bracing and just three sets of concrete ballast to tie the shed structure down and prevent it from being blown away. Only two lengths of column would be needed across the whole building, these structural feet essentially comprising two projecting prongs at either side of columns that can be extended and adapted for other sites as and when needed. Finally, unusually, the team proposed hydroponic cultivation for the roof plants growing in water instead of soil.Mercato Metropolitano began in 2015 with a pilot project during the World Expo in Milan, regenerating a 14,000m2 disused railway station. Set up by Italian businessman Andrea Rasca, the heavily branded venture made a move to London, successfully opening a popular venue in a former paper factory in Elephant and Castle in 2016 apparently after a chance meeting with Mayor Sadiq Khan. Now there are three more: one in a Grade I-listed building in Mayfair; one in Elephant Park; and another, perhaps most suited to its bougie food prices, in Wood Wharf.Mercato Metropolitano claims its core aim is regenerating areas and bringing communities together, as well as being sustainable and inclusive in its offering. Its focus is on sustainably sourced products, artisan producers and being hyper-local. Its dreaMM campaign aims to nurture and support young businesses, transforming them into budding entrepreneurs. Mercatos key rules for the markets programme were to serve food on crockery, with cutlery, and have a central wash-up area for these, eliminating plastic waste; to have a 24-hour biodigester for breaking down organic food waste into biogas and fertiliser; to send no waste refuse to landfill; and to provide flexible space for local food traders and community activities.During the pandemic, the market was put on hold. And, with the wind-up of Webb Yates architecture arm, a new tender was put out to take the project forward in its construction phase. Hotel, bar and restaurant specialist Clark Architecture, led by Anthony Clark, was brought on board, having completed Mercatos other London venues.At about the same time, two other consultants were brought into the project to value-engineer the design. The first element to go was the second-storey hydroponic farm. Specialists suggested that the multi-span polytunnels would work best in a large shed rather than on a roof and, in view of the additional weight of the water, it was decided that a rooftop community garden instead would be the best compromise.The next elements to come under scrutiny were the external ducts and chimney flues, which provide extraction from cooking zones. They were deemed oversized, but Anthony Clark and his team fought hard to keep them as they are. Aesthetically they are a major part of the sheds visual appearance and typical of Webb Yates exposed M&E design. Theyre a genius part of the design, says Clark. Theyre very low-tech.When the project started on site, more issues arose. Beneath the car park were several Second World War air raid shelters. Although the design took account of these, additional undocumented tunnels were discovered, which limited the structure to one storey. The team had to conduct plate tests to ensure the structural loads onto the markets bespoke-designed timber feet would work.As there was a 1.2m drop across the site, drains had to be put in place around the sites perimeter and the car park resurfaced with asphalt to tackle surface water concerns. Building Control was cautious about the buildings structural integrity, sitting so lightly on sloping ground, and didnt sign off the project until it was literally about to open.The scheme that has so laboriously been built is a large, airy shed, clad in translucent polycarbonate cladding simply fixed so that it can be easily removed, if needed. The demountable structure of glulam columns and beams with CLT infill panels all sits lightly on the ground as envisaged seven years ago, but the feet for the columns are made out of standardised steel plates instead, due to budgetary constraints.The timbers have been set out on a kiosk grid to the standard dimensions of the scrapped polytunnels. Bolted connections and waterproofing systems mechanically fixed in small sections also enable localised repair in the event of damage. The difficulty was not knowing who was going to come in, says Anthony Clark, pointing out that the schemes adaptability was about both functionality for the different vendors and circularity.The ducts and chimneys are a real celebratory moment, says Redbridges Marc Clark. The symmetry is key. Hes right. Standing along Clements Road, the scheme perhaps seems the most stripped-back shed-like form there can be for good reason but it should be celebrated that the flues and chimneys were kept as originally designed, with vents boldly placed on the column gridlines.The flues were reduced in height slightly, but the simple, main moves are still evident. Shiny, wide and tall chimneys, coming out of the external sides of the faade, both give articulation to an otherwise simply detailed, empty expanse and hint at the sheds uses within. They are the key aesthetic of the scheme in terms of proportion and set a horizontal datum for the long elevations so that the sloping ground isnt immediately noticeable.Along the north edge of site are the back-of-house spaces biodigester and zero-landfill recycling facilities simply cordoned off by an acoustic wall to keep the noise down.A mezzanine level has been built inside the hall for community use but as of February, it remained unused. Provision is left for a lift and stair core to one side. Stage two including this and the rooftop garden is expected to get under way in the next eight months.The L-shape of the market can be changed and set up in a different way, if needed, says Cole, pointing to the flexibility of the sheds redeployable modules. Its essentially giant Meccano. Webb Yates went as far as to bring a contractor and cost consultant on board to price the hypothetical eventuality of disassembly and reconstruction. We wanted to show it was feasible, Cole says.At the time of opening last year, filled with more than 20 traders local to Ilford, the market drummed up plenty of excitement in the local press. However, since then, prospects have changed and it has become clear Mercatos financial performance over the past couple of years has taken a drastic hit. At the end of last year, founder Rasca resigned and a new director was appointed. In December last year the group surrendered the lease of its Elephant Park site to a third party.Although the market isnt operating at full capacity, the team is still pleased. Its a beautiful outdoor structure, says Marc Clark. The low-tech structure is truly flexible, and its an example of a fully demountable structure: everyone agrees it could be used for something else. Hopefully, with Mercatos change of management and a bit more investment the scheme can live up to its intentions of being an incredible asset for Ilford and the local community.And, technically, despite its numerous challenges, this scheme provides learning opportunities for others and shows that, with forward planning, demountable architecture is possible.Architects viewHaving collaborated previously with Mercato Metropolitano, Clark Architecture was appointed at Stage 4 to help move the Ilford project forward. Construction was planned to start on site in late 2020. The team was determined to deliver the project for the community after the unavoidable disruption of the pandemic.The building is essentially a covered market and therefore has no heating or cooling demand. It is open to the elements at the base of all faades and at the eaves to allow fresh air to circulate and to prevent overheating in warmer months. Plastic reusable wind curtains can be installed to provide a sheltered lobby when required in colder months. The building is considered to have low energy demand with respect to Approved Document L2 (Conservation of fuel and power).Timber lends itself to reuse and was the natural choice for a sustainability-focused temporary community space. The building is formed from glulam columns and beams with CLT softwood infill panels at low level and polycarbonate cladding at high level. The roof is a softwood CLT slab covered with a single-ply membrane. Internally, the language of the various kiosks, services and centralised areas creates a cohesive feel through the use of standard sawn timber planking.The acoustic fence was also specified to be demountable. The internal face is clad in Quietstone light a rigid, durable absorber made from 94 per cent recycled expanded glass beads, while self-bearing panels are mechanically fixed direct to walls for easy maintenance and demountability.The next phase of the project intends to unlock the multipurpose mezzanine space and create a community garden on the roof. Pre-planning applications have been discussed with the London Borough of Redbridge, whose feedback was positive. Were looking forward to seeing the structure evolve to serve both its current and future communities.Anthony Clark, director, Clark ArchitectureEngineers viewThe brief, which centred around a building that would occupy a site for only five years, was the perfect opportunity to explore the principles of circular design. The compressed building lifespan meant that not only was a demountable timber frame the sustainable choice, but one that made the project economically viable, extending the return period of the initial capital expenditure.Demountability was core to the structural philosophy and informed both the overall arrangement and detailing. Recognising that the current configuration might not always work on future sites, the grid was rigidly set so that the glulam timber components formed a kit of parts, allowing the structure to be re-assembled in arrangements to suit other plots. Connections between the timber members were detailed with clip-in concealed connectors that allow the elements to be taken apart without any damage or modifications that might hinder their re-use.Foundations were also initially conceived to be in the form of adjustable timber feet that bear directly onto the car park surface and, at the same time, take out level differences across the site. However, below-ground structures and budget constraints meant these didnt make it to the constructed frame.The novel brief of this project led us to innovate solutions, ending up with a truly demountable structure (the feasibility of which was demonstrated through a costing exercise between a cost consultant and contractor for a hypothetical building move).While these solutions certainly threw up new challenges, it helped shed some light on to how we might adapt designs of more permanent structures to be disassembled in the future.Dan Cole, associate, Webb YatesWorking detailManufactured in Italy by X-LAM Dolomiti, a company well-versed in offsite prefabrication of timber structures, the exposed engineered timber frame revolves around the principle of repeating standardised elements.This serves the dual purpose of reducing the initial construction time as well as allowing it to be easily moved and reconfigured without the need for additional bespoke elements or excessive waste. Due to Covid-related travel restrictions at the time, X-LAM handed over erection of the frame to UK-based companies B&K Hybrid Solutions and Oyster Design and Construction. It was delivered in eight loads to coincide with the assembly programme.A unique plate test methodology was devised during early conversations to provide some information as to the performance of the installed foundations under load. Plate testing equipment was used to load the pads and mimic the loading of the proposed structure in an attempt to show that the settlement encountered was within the limits allowed by the structural design, and again to develop the lifting plan and position of the mobile cranes around the site for the most efficient and safe assembly of the frame.A flame-retardant impregnation treatment a polymeric blend of organo-phosphate and nitrogen salts was applied to the timber to achieve a Class 0 rating. The cladding and waterproofing were fixed in small sections so that repair and maintenance could be carried out in localised sections and not cause disproportionate replacement of materials.Panels were installed by means of a panel coupling, provided by tongue-and-groove joints and aluminium fixing clips fixed back to a secondary structure.Anthony Clark, director, Clark ArchitectureProject dataLocation Mercato Metropolitano Ilford, 3 Chadwick Road, London IG1Start on siteOctober 2020CompletionJuly 2024Gross internal floor area1,128mConstruction cost2.9 millionConstruction cost per m2,570ArchitectInterrobang (up to Stage 4), Clark Architecture (Stage 4 onwards)ClientMercato MetropolitanoStructural engineerWebb Yates (up to Stage 4), Rebus Engineering (Stage 4 onwards)M&E consultantWebb Yates (up to Stage 4), Bocca Consulting (Stage 4 onwards)Quantity surveyorJackson Coles (up to Stage 4)Project managerClark Architecture, MilbankApproved building inspector StromaTimber specialist X-Lam DolomitiLocal timber specialist B&K Hybrid SolutionsAcoustic consultant Blackbird AcousticSurface water drainage Pura DesignMain contractorOyster Design and ConstructionCAD software usedRevitSustainability dataPercentage of floor area with daylight factor >2%N/APercentage of floor area with daylight factor >5%N/AOn-site energy generationNilHeating and hot water load152 kWh/m/yrOperational energy183 kWh/m/yrTotal energy load235 kWh/m/yrCarbon emissions (all)32 kgCO2/m/yrAnnual mains water consumption3.3 m/occupantAirtightness at 50PaN/AOverall thermal bridging heat transfer coefficient (Y-value)N/AOverall area-weighted U-valueN/AAnnual CO2 emissions32 kgCO2/mEmbodied carbon140 kgCO2eq/mWhole-life carbon160 kgCO2eq/mPredicted design life50 years