Building sights: how offsite construction could help solve the housing shortage

Posted on February 1, 2021 by jamescarson2014

**“Offsite construction” by psd is licensed with CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/**

Long waiting lists, high rents, thousands sleeping rough, millions living in insecure or unsuitable homes and a generation of young people priced out of the market: these are the hallmarks of the UK’s broken housing system.

In England, the government is committed to building 300,000 new homes a year by the mid-2020s. But in 2019, the number of new homes amounted to 170,000 – fewer than half of which were affordable homes. It’s a situation that is almost certain to get worse. Housing analysts have suggested that the restrictions caused by the coronavirus pandemic in 2020 will mean a 30% reduction in homes delivered.

Local authorities are rising to the challenge of the housing crisis. Between 1999 and 2002, councils delivered just 60 new homes as a consequence of central government housing policy. But in recent years councils have been returning to housebuilding in large numbers. A 2019 RTPI report found that:

“…more than two thirds of local authorities are now involved in directly delivering housing and local authorities are delivering homes in numbers not seen for 20 years.”

In the same year, The Guardian newspaper highlighted some examples of council housing projects:

“Bournemouth is building housing above many of its surface car parks, and has won planning awards for the results. Wigan is transforming tricky former mining sites with an exemplary programme of housing for older people. Exeter has one of Europe’s largest Passivhaus schemes underway, while Liverpool is developing rent-to-buy homes.”

Going modular

But if councils are to succeed in their efforts to deliver more affordable, low carbon housing, they will need to change the way homes are built. Increasingly, prefabricated modular construction is being seen as a way to meet some of the demand for new housing. Built offsite in factories, with fittings included, prefabricated housing offers comfortable, well-insulated homes that can be constructed more quickly than traditional building. Offsite construction can deliver a modern apartment block in half the time that it would take to build using traditional methods, which means that units for sale or rent can start making money more quickly.

An article in the 12 November 2020 issue of MJ magazine reported further benefits, noting that:

“…these homes are delivered with up to 40% less carbon, fewer defects, and less disruption to neighbourhoods where sites are located. Once completed the fact they are made in a factory is not obvious to the passer by or occupant, it is just great housing, beautifully built, with low running costs.”

A shortage of skilled labour presents another reason why the old ways of building homes need to change, as a 2016 review of the construction market highlighted:

“We will not have the labour force to deliver what the country needs by working in those ways, and those ways will not create enough added value for clients or suppliers to allow construction firms to prosper, and make those investments in our people and performance.”

The report demonstrated that prefabricated housing can make a significant difference to satisfying demand:

“Tokyo alone is able to build nearly the same number of homes per year that the UK delivers nationally. This is purely due to the reliance on a different delivery model for single family homes which benefits from the mass market cultural acceptance of pre-manufactured modular housing.”

Housing the homeless

Further evidence that modern methods of construction can work well has come from a project in Cambridge, where six modular homes were installed on a temporary site to house local homeless people. A report by the Cambridge Centre for Housing & Planning Research noted that residents were impressed with the design, space and quality of the modular units, and were keen to be involved in efforts to build a thriving community.

The Cambridge project is especially important in the light of the UK’s large number of rough sleepers and ‘hidden homeless’. In March 2020, more than 14,000 homeless people were housed in England as part of the ‘Everyone In’ initiative to take rough sleepers off the streets during the first wave of the pandemic. The programme was hailed as one of the leading successes of the government’s coronavirus response, but it ended in May and has not resumed during the current lockdown.

The future is modular?

So, could modular construction offer a solution to the UK’s housing shortage? Recent research published in the Journal of Engineering, Design and Technology set out to compare the traditional approach with modular construction, and to assess whether a shift in construction systems offers the potential to alleviate the UK’s domestic housing crisis. The study stressed that more research was needed to provide greater certainty about how modular methods could be more effectively grafted onto the current UK construction practices. However, the authors concluded that:

“…modular construction promises strategic solutions to the lack of affordable housing currently experienced in the UK.”

In the meantime, recent developments suggest that the prefabricated housing sector seems to be going from strength to strength:

A 20,000 sq ft unit will be the manufacturing site for a new modular housing company in Durham, with plans to produce 1,000 modular homes a year.
A modular housing developer owned by Ikea has signed a 750-home deal with a housing association in the south of England.
Planning consent has been granted for 185 homes to be located in Bristol after they are shipped in from a factory in Yorkshire. Half of the homes will become part of the city council’s affordable housing stock.

The numbers of prefabricated homes are still too low. But if this trend continues, offsite construction might start to have a bigger impact on the UK’s housing shortage. The days of bricks and mortar could be numbered.

Further reading
More from The Knowledge Exchange blog on modern methods of housing:

Going through the roof: could building upwards address London’s housing problem?

Posted on September 23, 2016 by jamescarson2014

The Ter Meulen Building, Rotterdam: 21st century residential apartments built on top of a post-war shopping centre

The housing challenges facing London are well documented::

London needs around 50,000 new homes a year, but housebuilding is running at around half that.
Between 2005 and 2015, private rents in London rose by an average of 35%.
Future projections suggest there will be 9m people in London by 2020, 10m by 2030 and 11m by 2050.

There are now serious concerns that the lack of affordable housing and rising rents risk driving key workers out of London, and may cause businesses to think twice about locating in the capital. But as well as triggering dire warnings about the future of London and the UK economy, the housing crisis has also prompted increasingly creative ideas on how to solve it.

Going up

Last year, Darren Johnson, who represented the Green Party on the Greater London Assembly, proposed five ideas to secure land for affordable homes. One of his proposals was to build additional storeys on top of existing buildings.

Johnson suggested that this approach has many advantages over demolishing existing properties and building new homes, including:

a shorter period of disruption for residents;
more environmentally friendly than demolition and rebuilding
an opportunity to refurbish the existing homes

He offered the example of the Ducane Housing Association in Hammersmith, which built 44 new homes on top of two 1970s buildings. Based on data from London’s Borough Councils, Johnson estimated that almost 50,000 new homes could be built using Ducane’s example.

One potential stumbling block is the difficulty of getting planning permission for intensive construction projects in the heart of active communities. However, in July 2015, the Treasury signalled the government’s intent to end the need to obtain planning permission for upwards extensions in London.

Building on public buildings

Another approach, on similar lines, is the idea of building new homes on top of publically owned buildings. In 2015, WSP professional services consultants conducted a survey to gauge interest in the idea. Among their findings:

61% of respondents supported the idea of allowing private developers to refurbish government buildings, allowing them to make their money back by building additional housing on top of the refurbished building, which they could sell for profit.

Over 60% of Londoners would happily live above a library, while 44% would be willing to live above a government administration building, and around a quarter of Londoners would be willing to live above a school or hospital.

The WSP report went on to suggest that developing all available sites by building apartments above all available public buildings in London could provide over 630,000 residential units.

“Of course we acknowledge that not every building will be able to be redeveloped in this way, but even targeting one in every two municipal buildings could go a long way in solving the housing crisis, providing 315,000 homes.”

These homes, the report argued, would be most suitable for key workers employed by these facilities, or by students, older people and young professionals. Some may even house those working in the facilities below.

One landlord is already exploring the idea with several London councils. Apex Housing Group has experience of converting airspace above properties into luxury penthouse apartments. Managing director Arshad Bhatti believes the principle could be applied to affordable homes:

“We are working with a number of local authorities across London and expect airspace development projects will help bridge the gap between demand and supply of new homes in London – crucially with minimum lead times, and offering maximum value for property owners.”

The view from overseas

The idea of building up may be relatively new to London, but other densely populated cities have already been exploring its possibilities.

In Rotterdam, developers have been combining ultra-lightweight materials to build apartments on top of a 1940s shopping centre.
In New York, a developer is planning to construct a nine-storey condominium on top of apartments dating from the 1950s.
In Paris, three prefab dwellings attached to the rooftops of existing buildings were completed in January 2016.

The architects of the Paris project believe it has multiple benefits:

“Building on top of the roofs is not only an ecological and economical solution, it’s working against the urban sprawl that kills the social link. It’s also a contemporary way to discover new perspectives of the city, a new Paris above the horizon.”

But not everyone is happy with the idea. Residents in the existing apartments beneath the proposed New York condominium are concerned that the wear and tear of construction could damage their properties. And they’re also worried about the stability of the columns supporting the new building.

The only way is up?

Clearly, building on existing properties is not without its problems. But as the housing crisis in London intensifies, and spreads to other parts of the UK, it’s an idea that may no longer be regarded as pie in the sky.

If you liked this post, you may also be interested in other blog posts on suggestions for tackling the UK housing crisis:

BIM: the digitisation of the built environment

Posted on May 23, 2016 by staceydingwall

by Stacey Dingwall

Last month, the Department of Architecture at the University of Strathclyde hosted a seminar on the digitisation of the built environment and how digital is disrupting the construction sector. The event focused on the use of Building Information Modelling (BIM), and its use in Scotland in particular.

What is BIM?

As defined in the UK government’s industrial strategy, BIM is “a collaborative way of working, underpinned by the digital technologies which unlock more efficient methods of designing, creating and maintaining our assets”. Specifically, it embeds key product and asset data, and a 3D computer model that manages information throughout a project’s lifecycle. BIM has been described as a “game changer” for the construction industry, and can be used in the construction of new buildings as well as retrofitting and refurbishment.

Speaker: David Philp, AECOM

The first presentation came from David Philp, Global BIM/MIC Consulting Director of AECOM and the Chair of the Scottish Futures Trust’s BIM Delivery Group. The Group was established on the recommendation of the Scottish Government’s 2013 Review of Scottish Public Sector Procurement in Construction, and tasked with delivering a BIM implementation plan for the country, which was published in September 2015.

David focused on the pathway set out in the implementation plan for Scottish public sector projects worth over £4.32m to adopt Level 2 BIM by 2017, as recommended by the 2013 review. In England, the industry was required to have adopted Level 2 by April of this year; a recent survey carried out by Construction News found that almost 70% of main contractors, consultants, professional services and clients had either fully embedded the Level 2 standards into their systems, or were using Level 2 when it suited the project.

The suitability of different levels was something that David stated was important to consider on a case by case basis – while the goal is to be Level 2 capable, sometimes Level 1 may be more appropriate. This is different to the approach taken in England, where the government has mandated that only Level 2 should be used from now on. As highlighted by David, the Chancellor’s latest Budget also included a commitment to “develop the next digital standard for the construction sector – Building Information Modelling 3 – to save owners of built assets billions of pounds a year in unnecessary costs, and maintain the UK’s global leadership in digital construction”.

David also described the benefits of using BIM, particularly Level 2, in construction projects, in terms of efficiency, reducing risk and the creation of more sustainable and intelligent infrastructure. He also touched on the use of BIM in the construction of the High Speed rail link between London and Birmingham (HS2), due to begin in 2017. BIM has been described as the “backbone” of the HS2 project, which will be the largest BIM project undertaken in Europe so far.

Speaker: Professor Bimal Kumar, Glasgow Caledonian University

The seminar concluded with a presentation by Professor Kumar, Head of BIM at GCU’s School of Engineering and Built Environment. Professor Kumar, who works with David Philp as part of the BIM 4 Academia Working Group spoke about his department’s work in embedding BIM into the taught curriculum of the courses they offer, as well as his work in developing a BIM strategy for NHS Scotland, which involved mapping their existing processes to BIM processes.

Professor Kumar also shared some of his personal opinions on the adoption of BIM in Scotland, stating his belief that it will take another 30 years before Level 3 is fully adopted. He emphasised the need to ‘demistify’ BIM, as too many organisations still think that it will cost them too much in terms of effort and money to comply with the standards.

Overall, the seminar offered a good opportunity to find out more about something that, while mystifying to most, is set to transform the global construction industry.

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PassivHaus … a home for all seasons?

Posted on July 3, 2015 by jamescarson2014

Image by Pichler Haus, released under a standard Creative Commons Licence

By James Carson

This week, eight contenders are waiting expectantly for the results of the 2015 UK PassivHaus Awards. The awards celebrate sustainability and good building design, with the focus on the PassivHaus concept.

What is PassivHaus?

PassivHaus is an approach to building that is designed to eliminate the need for traditional central heating systems by combining:

excellent levels of insulation
passive solar gains and internal heat sources
excellent level of airtightness
good indoor air quality, provided by a whole house mechanical ventilation system with highly efficient heat recovery.

Since its small beginnings as a German-Swedish collaboration in the 1980s, over 30,000 buildings around the world have been built using the PassivHaus approach.

The benefits of PassivHaus

Energy efficiency lies at the heart of a PassivHaus building. The PassivHaus Institut, which plays a leading role in promoting the concept, has claimed that these buildings can achieve energy savings of up to 75% compared to average new builds. PassivHaus proponents also claim that the buildings have significantly better levels of air quality, and greatly reduce carbon emissions.

Practical issues

While the long-term energy savings are impressive, PassivHaus buildings are not without their critics. Among their concerns:

Cost: The higher standards of PassivHaus buildings, including triple-glazed windows, mechanical ventilation systems and vacuum insulation, all add to the costs of PassivHaus construction. The consensus seems to be that PassivHaus will increase build costs by 15% to 25%, and it’s believed that the higher costs have limited the concept’s application to a handful of private housing developments in the UK.
Construction time: Because of the optimum performance demanded of them, PassivHaus buildings can take longer to install. In the Republic of Ireland, concerns about slower construction times during a serious housing shortage has prompted the government to oppose plans by local authorities in Dublin to make the PassivHaus standard mandatory for new homes. PassivHaus proponents in Ireland have condemned the moves as short-sighted, and claim that PassivHauses won’t slow down construction.
Adaptability: Another criticism of the PassivHaus concept is that it’s not readily adaptable, and that structural alterations may interfere with the integrity of a PassivHaus building.

A building or a lifestyle?

There have also been claims that residents may themselves have to adapt to PassivHaus living.

“Building a house to this standard means agreeing to live a certain lifestyle, which if lived to the book can work very well, and has been proven to do so time and time again. You must appreciate, however, that building such a home is a lot of trouble to go to if ultimately you do not want to live the PassivHaus lifestyle.” (The Green Home)

However, PassivHaus supporters dismiss the idea that these buildings are too complicated to maintain:

“The ventilation system, not common in conventional buildings, is user-friendly and easy to operate with fewer controls than a normal television.”

PassivHaus in the UK

The PassivHaus concept was slow to take off in Britain, but more and more UK architects have become interested in PassivHaus since 2013, when the government committed to implementing zero carbon homes from 2016. The zero carbon homes standard will require house builders to decrease all carbon emissions from energy arising from fixed heating and lighting, hot water and other fixed building services, such as ventilation, in new homes. It’s worth noting, however, that the zero carbon standard is less strict than PassivHaus.

The PassivHaus approach is not limited to residential properties. Among the buildings shortlisted for the UK PassivHaus awards this year are a primary school, an office and an education centre.

Elsewhere, the University of Leicester’s Centre for Medicine is currently under construction, and is set to be the UK’s largest PassivHaus building. It’s estimated that the high levels of insulation and a state-of-the-art heating, cooling and ventilation system will reduce the university’s energy bill for its new teaching and research facility by 80%, compared to the previous building.

PassivHaus may also be able to contribute to alleviating Britain’s housing crisis. A social housing project currently under construction in Rainham, east London, aims to demonstrate that PassivHaus is a commercially viable solution to the UK’s shortage of affordable homes. The builders of the 51-home project claim that this will be the first PassivHaus development to be let entirely at affordable rents.

Future prospects

Inadequate heating, poor insulation and high energy costs have become significant factors in the rise of fuel poverty among households in the UK. At the same time, there is a pressing need to reduce dependence on fossil fuels. So, it may be that the buildings being showcased at this year’s PassivHaus awards may come to be seen as ahead of their time.

The Idox Information Service can give you access to a wealth of further information on housing; to find out more on how to become a member, contact us.

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