In recent years there has been a growth in the development of modular homes which have been designed from the outset to be relocated to a new site – particularly for the provision of affordable homes. Many determining factors come into play: from skilled labor shortages, production time efficiency, quality assurance, to sustainability and circular economy considerations.
But the case of Chris Payne House has set a new precedent: its dismantling in one London borough and relocation to another demonstrates various instructive lessons that could be applied to a new wave of reusable modular homes.
The original building, designed by AHR for registered provider Hyde Housing, was completed in 2005 on land leased from the London Borough of Southwark. The building used volumetric and modular construction techniques to provide flexible, demountable and relocatable affordable homes. The modules were built by BUMA, a manufacturer based in Poland.
In 2018, Southwark demanded the return of the land, as the lease was ending. Hyde had the option of demolishing the building, moving it to a new location, or selling it to a new owner. Fortuitously, the London Borough of Ealing at this time had several potential locations for such a project and were interested in purchasing the building for use as temporary accommodation for families in emergency need.
AHR were again tasked with launching a planning application for the relocated houses, which were renamed after a former Ealing councilor who died in 2014. McGregor White Architects was then appointed for post-contract services and as contract administrator for dismantling and relocation. 12 miles to Hanwell, as well as carrying out the refurbishment and adaptation of the program from 18 one and two bedroom apartments to 16 one, two and four bedroom apartments.
The reuse of Chris Payne House sets a precedent by preserving the embodied carbon of the original construction and providing a flexible solution to housing on sites in the interim before being moved to other locations if required.
But what happens when it comes time to move these buildings? Is it practical and what are the challenges in the design, planning and logistics of relocating an existing building to a new site?
There was no playbook to follow… the team had to develop the plan from first principles
As far as we could tell, an apartment building like this had never been moved before. There was no manual to follow to complete this type of project, so the team had to develop the plan from first principles.
To design and plan the move, members of the team that delivered the build in 2005 were called in to join the new project team and luckily all were available and up for the challenge, including the original QS, who came out of retirement. be part of the project. This enthusiasm and commitment proved essential, as there was a lot of knowledge retained and nuggets of information that were not communicated in the “as built” drawings. It demonstrated the importance of having access to reliable building information for future relocation projects.
Designing the building to be as flexible as possible and viewing building policy or regulations as a baseline to be exceeded, rather than a goal to be achieved, certainly helped the project as well.
This flexibility helped answer the question of whether the relocated building should be treated as new construction or as a renovation project. When it came to building control, planning, and various other stakeholders, this issue had the potential to become a troubling gray area.
The improved standards to which the building was already designed and its adaptability helped to minimize uncertainty and stakeholders were able to negotiate appropriate approaches. In the event the building was treated as a mix of new build and existing, and agreeing this approach from the start was key to helping to successfully define the brief.
Transporting an entire building on the back of lorries a distance of 20 km through London was a complex logistical operation. The project team included logistics experts and transporters to ensure that it was carried out in a safe and efficient manner. The building modules had to arrive at the Ealing site in the correct order, which was not necessarily the order in which they had to be dismantled. The team also had to think about maintaining the stability of the building through disassembly and reassembly, in addition to factoring in time and London traffic.
It all amounted to a huge juggling exercise. After months of planning, dismantling, transporting and reassembling the construction took 18 days from start to finish. The subsequent renovation took another four months.
A few days after the building was handed over, families began moving into their new homes. The London Borough of Ealing was extremely pleased with the quick delivery of the project, which took less than half the delivery time of an equivalent new building.
The move and renovation saved 219.5 tonnes of embodied carbon compared to an equivalent new building
Modular home relocation is definitely something to consider going forward from a sustainability standpoint. Over 95% of the materials from the original building were reused in the relocated building. Our calculations showed that the move and renovation saved 219.5 tonnes of embodied carbon compared to constructing an equivalent new building on the same site – even taking into account dismantling, transport and new concrete foundations.
The renovation and modernization of the houses also included new and improved heating and hot water systems, energy-efficient lighting and electrical installations, and a solar photovoltaic installation, which together reduced the CO in use.2 53% emissions. The cost to the client was considerably lower than that of a new construction, estimated at only 40% of the cost of an equivalent, in addition to being delivered in half the time.
Chris Payne House has already paid off with a successor project. McGregor White Architects is now working with the Pan-London Accommodation Collaborative Enterprise (PLACE), a development company owned and supported by four London boroughs, to develop relocatable modular homes for temporary accommodation to be used at sites in the meantime.
And AHR continues to develop and advance BIM workflows to facilitate the design and modeling of modules and prefabricated construction elements, as recently demonstrated by its Gillender Street housing project for Mount Anvil in Tower Hamlets.