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Last edited 18 Nov 2022

Twenty winters of Bedzed

[edit] Introduction

From Sgt. Peppers to Sutton Pioneers ‘It was 20 years ago today…', that this scheme, targetting zero-carbon living, hoped to persuade others to sing along, to change the norm, and now two decades later its tune still rings true. This is a reminder of a development, in fact a community of people, of 82 homes, 18 live/work units and 1,560m2 of workspace with community facilities. The scheme was built for the Peabody Housing Trust on a brown field site which might more accurately be described as an undesirable land fill site on the edge of London. It was the result of a collaboration between Bioregional as developers with Bill Dunster Architects (now Zedpower), Arup Associates as engineers and a number of other partners singing to the same tune about holistic low impact living at scale.

[edit] Bedding down for winter

Completed in the summer of 2002, by October of that year most tenants would have settled in and been preparing themselves for the first winter trial. They were armed with thick walls from locally made bricks, a recycled steel structure, a community scale infrastructure, supported by large PV clad winter gardens, rotating wind cowl exchanging exhaust heat and just a single towel rail in the bathroom for heat, imagine the comparison.

Today, November edges towards what some have dubbed as the global winter of discontent of 2022, where housing crisis, meets energy cost crisis, meets cost of living crisis, with war ongoing in Ukraine, Covid again rising in places, as many continue to work from home. Here are some reflections described in the context of the time intermingled with extracts from the Architect, on the origins, achievements and failures of what is now over two decades ago, by the Beddington zero (fossil) energy development, better known as Bedzed. A scheme more prepared for this coming winter in 2022 than most new houses being built today and justified from almost every angle possible in its considerations to the ongoing climate crisis.

The award winning scheme was both lauded and lambasted at the time of completion but perhaps now after what sometimes seems like a twenty year circle back to the start, time has been given to better assess and learn, even though the action needed at that time wasn't taken up as it was hoped. As Architect Bill Dunster, who with his team hasn't stopped building ZEDs, put it in an interview last year "Bedzed was an attempt to ask some questions, it doesn’t pretend to have all the answers, but the questions are probably worth running through". One might say these questions need asking now more than ever and perhaps many answers still lie in the walls of Bedzed or at least the holistic approach adopted by the team.

[edit] In 2000

In 2000, largely as a result of the Urban Task Force set up in the late 90's ( and the earlier publication 'Towards an urban renaissance'), the urban white paper 'Our Towns and Cities – the Future' was published. This in turn influenced Planning policy guidance note 3: Housing (PPG 3) which was published in the same year.

It took on some of the recommendations that had followed through from the late 90's to early 2000, many of which seem to be still familiar when reading recent policy recommendations, such as; design-led urban regeneration, special urban policy areas, reform of the planning system, involvement of local people in decision making, building 60% of new housing on brownfield land, better use of existing housing stocks, relaxation of planning authority standards relating to density and distance between dwellings, relaxation of parking standards away from road oriented design, supported by better non-vehicle planning and design quality.

[edit] Precedents

“We spent some time travelling round the UK looking at various alternative homes, solar homes and autonomous houses such as Brenda and Robert Vale at Hockerton, their own house and various alternative habitation solutions. We felt there was a massive gap between the people who were doing one off building physics experiments, like those at the Centre for Alternative Technology (CAT) and the urban or suburban housing that was being built. So how could this be brought back to the city, when in the 90’s most architects were busy proposing high or medium rise walk up blocks of flats with little understanding of energy-efficient, renewable energy integration or circular economy. There was no real discussion about meaningful responses to climatic change and every time we tried, we were knocked back, mainly because it just wasn’t mainstream enough."

[edit] Car-free

"Working on many cutting edge office buildings with top consultants whilst working for Michael Hopkins, we found that some of the ideas being practised in the low carbon work place were not making it through to housing, at all. On the Nottingham University new campus, on the Raleigh Bicycle factory at Hopkins we had the opportunity to be able, for the first time to not design around vehicles and car layouts, but around pedestrian orientated circulation patterns and solar access and the prevailing wind and we really felt there was just no point any more in designing yet another office Park if the carbon footprint of people going to work with so high."

[edit] Mixed-use

"So Bedzed was an attempt to bring everything together, muddle it all up again and take another look. Let's Not build anymore dormitory suburbs because you can see what that looks like over the fence and go back to the complexity of the more mediaeval city, that has 24 hour occupation and has lots of different activities going on in the same place."

[edit] In 2002

Early in 2002 the Queen mother passed away, local elections were held following the re-instatement of Tony Blair as PM the year before, 50% of the UK population had access to the internet, car sales in Britain had reached a record high for the second year running, and last minute preparations were in place for the 8th Conference of Parties due to be held in India during that November.

The Kyoto Protocol was signed by all European Union member states and the European Union subsequently published the EU Directive on the Energy Performance of Buildings (EPBD) in December 2002. This legislation recognised that buildings were responsible for about 40% of Europe’s energy consumption and it bound EU member states to achieving a reduction in total end energy consumption and an 8% reduction of CO2 emissions by 2010 when compared to the base year of 1990 in order to comply with the EU’s commitment to the Kyoto Protocol (EC 2002).

[edit] A landfill site

"We kept competing in the social housing circuit and kept getting knocked back and after about two years working with Nicole Lazarus we managed to get the interest of the Peabody Trust in initiating this housing experiment. A very rundown part of London which had nothing much going for it at that time, it was disused waste treatment farm historically, nothing happened there probably because of the smell and the land of all around has been zoned for the similar anti-social activities ranging from landfill dumping, gravel extraction, incineration etc. So we took what was a potentially very unloved little bit of south London, which was only 20 minutes from London Victoria within walking distance of a railway station."

[edit] Setting density

"The idea being to try and turn that into a kind of suburban version of the Centre for Alternative Technology. So we tried to get it so that we could fit all the 3.5 million new homes that were required in the UK at that time on existing stocks of brownfield land, so not building on greenbelt, which then set the density for Bedzed, which approximated to Soho in central London, but everyone gets a garden and reasonable solar access. Then use the latest building physics models as we were aware of at the time, that you could have zero spec homes, and really only need a little bit of space heating and the domestic hot water load."

The ZED in Bedzed stood for Zero (fossil) Energy Development, a building with passive envelope to reduce the demand for heat and power to a point where energy from renewable resources generated on-site becomes economically viable. About one third of the energy requirements being met by solar electric with the rest coming from the schemes own centralised heat and power plant, (initially at least) and each flat contain a single electric towel rail as a heating back up for when the winter sun didn’t shine.

The scheme was both heralded a swell as criticised at the time, by the industry and professionals, partly because of its appearance in resembling the homes of the popular children's tv characters at the time, the Telletubbies and because it did not come without its own problems in performance from overheating to energy production. It was however, one might say the first dense and holistic model of housing to reconcile a higher-quality affordable life and work style with a step-change reduction in the carbon footprint for an outer London dormitory suburb, at a time when energy efficiency was less than a mainstream concern when it came to the construction of new housing.

[edit] In 2003

[edit] Overheating

The summer of 2003 was particularly hot, throughout Europe with high temperatures particularly in France whilst it has been estimated 17% more deaths occurred in England during the same heatwave. During this time there reports and complaints of over heating issues in the sunspaces from residents at Bedzed. In 2009 the design team conceded that top floor sunspaces tended to overheat but noted this was the result of cost-cutting as they were designed with roof-level opening lights, helping keep sunspaces cool without compromising security, but these were left off as part of costs savings. Similar particularly high summer temperatures across were also seen in 2006, 2008, 2018 and 2022 and in 2022 the building regulation Part O was introduced.

The cost verses benefit of sunspaces remained a discussion point, with Bioregional removing sun-spaces from many of their following developments, whilst Bill Dunster and Zedfactory continued to support of their use with the addition of an eave level over hang. “They add about 7.5% to the build cost, increase the floor area by 15% and can be occupied for 80% of the year without needing any extra heating,” (as reported in Building magazine in 2009).

[edit] In 2006

[edit] Energy issues

From its opening, to around 2005 Bedzed covered about 80 percent of its energy through local onsite production, which included wind power, solar cells and the CHP unit. However in late 2005 / 2006, the CHP wood chip gasifier system became problematic and sadly the system was turned off and heating was provide by gas, meaning that by 2006 only 11 percent of local energy consumption was covered by renewable sources.

"Probably one third by solar electric panels, partially integrated in the glazing and roof and the rest to be provided by a wood fuelled combined heat and power plant, running off wood gas, which was developed in Sweden in WW2 to run vehicles, now called pyrolysis. That didn’t work very well and was then replaced by a wood pellet boiler ( though pyrolysis is still a promising technology and could be deployed at scale and still needs to be given research time) … so a lot of the ingredients were there."

[edit] Living Machine

The Living Machine mimicked the function of wetlands in purifying water, it is a biological treatment system with an ecosystem of plants, bacteria, algae, plankton, snails, clams and fish to process the sewage, the useable in toilets and irrigation along with the harvested plants. It initially worked well and was manned by a resident, however also in 2005 it became inoperative. Whilst reasons for this vary from problems with high maintenance to issues with replacing the previous caretaker of the system, however the effect was the same.

As the system wasn't working discussions with the local water supplier highlighted a number of issues, firstly the low water use at Bedzed (around 6,000 cubic meters) became problematic for the water company who normally made similar agreements on at minimum use of around 50,000 cubic meters water per year. Some studies also indicated that the energy consumption for pumping and aeration at the small scale of BedZED was not viable and both economically and environmentally connection to a central water supply was more efficient.

[edit] Code for Sustainable Homes

In 2005 the BRE Innovation Park opened, showcasing a number of low energy show homes. In relation to this the Code for Sustainable Homes was being developed, an assessment procedure to holistically assess sustainable housing developments from fabric to location and transportation links. In 2006 the UK Government formally introduced the Code for Sustainable Homes (DCLG 2006a) as part of a commitment that all new homes would be zero carbon from 2016.

The Climate Change Act was enacted 2 years later in 2008 and committed the UK Government by law to ensure that the net UK carbon account for 2050 would be at least 80% lower than the 1990 baseline, excluding international aviation and shipping.

[edit] In 2010

[edit] Passive design

"That was the main story really, so it required passive solar designs, solar access, good thermal envelope, thermal zoning, attention to detail on thermal bridges and lots exposed radiant thermal mass and passive heat recovery ventilation. And then a lot of care with embodied carbon, GGBS, recycled agregate, and local bricks and zero use of polyurethane insulation. Bedzed really was about if you got the main energy demand down to a fraction of a conventional UK home at that time, maybe one fifth, in theory it was just about possible to meet that demand with renewable energy generation on site."

The building envelope principles of Bedzed were very similar (but not identical) to what is now commonly known as Passivhaus, though it took another 8 years in 2010 for the first UK Passivhaus home to built. Whilst both standards apply similar principles of high performing fabric and heat recovery ventilation, there are differences in certain specifications and design principles. The most noticeable probably being the passive solar form and heat recovery, which in a Pasivhaus comes from a electrically fan driven Mechanical Ventilation Heat Recovery (MVHR), whilst in Bedzed it comes from its distinctive wind driven, rotating large, colourful wind cowls.

In 2010 the Energy Performance of Buildings Directive (EPBD) was recast to establish the ‘nearly zero energy building’ as the building target from 2018 for all public owned or occupied by public authorities buildings and from 2020 for all new buildings (EC 2010).

[edit] In 2022

The queen herself passed away in 2022 with King Charles in her place and just less than twenty COP's later even more so hopes for substantial action and solutions are being pinned both on this new environmentalist King as well as on COP 27, coming up this November in Egypt.

A time when the industry continues to define, redefine or refine zero carbon with a government again reviewing its net zero strategy around discussions of which technology roll out will save the day, from heat pumps to hydrogen. A time where parts of the industry continues to call for back to basics support for envelope and external cladding upgrades, which is surrounded by controversy, sensitivity and safety issues that were highlighted by the tragic Grenfell fire some 5 years earlier caused by the type and installation of external insulation. Now as the regulations and guidance have reacted to this event alongside changes to the Building Regulations that came into effect this year, with changes to Part L, the new part O covering overheating and even the industry proposed Part Z.

[edit] Low carbon social agenda

"Above all I suppose the intention was to provide a higher quality of life and more of a social experience than residential models at that time we are providing. So to give everyone the access to sunlight, their own garden and a place where kids could play in a reasonably secure environment .. and hopefully some of those ideas have come through. The social facilities, the power generation and the water treatment on site, the living machine, all these things did work for time, got replaced or upgraded and are still partially working. So everything as I say is not perfect, but it set an agenda which I think was intended to show zero carbon homes could have been nationally mandated by the year 2016 and that indeed was actually what was going to happen but well then it didn’t, primarily due to lobbying”

The Bedzed scheme might be seen as a testament to how far we could have been as we enter this winter, after another of the warmest summers on record or at least a continuing trailblazer to learn from and even in part replicate.

Quoted texts are taken from an extracted transcript of the interview with Maria Smith, Bill Dunster and resident Tom Nicholls for the Architecture Foundation in 2021. To watch the full interview visit the Architecture Foundation recording.

All images are shown with permission of copyright belonging to Duan Fu of zedpower.

For further details on design specifications and in use reviews use external links below.