Why thatched roofs have carbon concerns

The majority of reed used in thatched roofs comes from Europe (Image: Peter Cox |

Andy Dodson MCIOB from Solent University is researching the supply chain issues concerning reed – crucial for repairing thatched roofs.

What are you working on at the moment?

I am in the third year of a part-time PhD, researching stakeholder conflict and its impact on the management and use of reedbeds within the UK. My family background is thatching and, while I didn’t end up as a thatcher, it’s a craft I find fascinating. This interest extends into the supply chain. 

As a boy, a lot of my weekends were spent travelling up to How Hill in Norfolk to collect loads of reed with my dad, grandad and brother. As we got into the 1990s the number of trips decreased significantly, with us now getting reed delivered directly to the yard, with the vast majority being imported from continental Europe. 

While I was completing my undergrad dissertation I discovered that UK-grown reed now accounted for only 10% of overall consumption. My appetite was whetted but at the time I wasn’t in a position to take this further. Thankfully, when I started work at Solent University, my line manager was supportive of me undertaking a PhD to investigate these causes and the impact.

Why is this important to the UK construction industry now?

There are a variety of reasons. The vast majority of thatched buildings in the UK are listed. Historic England has a like-for-like policy when it comes to rethatching listed buildings: ie, if reed was on the roof then it needs to be rethatched with reed. This means there is an ongoing demand for good quality reed. A thatched roof should be extremely sustainable – however, with 90% of reed having thousands of carbon miles attached to it, it really does detract from its sustainability. 

Having a greater understanding of the causes of conflict will help the different stakeholder groups develop solutions to these problems, which should equate to more jobs. Over the past few years global events such as covid, the war in Ukraine and the Houthis attacking merchant shipping in the Red Sea mean that reed prices have fluctuated significantly. A more consistent and greater UK supply will help settle the price of reed.

What is new about this research?

The vast majority of research to date on reedbeds has either focused on it as a habitat or ecosystem, for sewage and wider waste water treatment or for different uses for the cut reed. A lot of research does acknowledge the presence of conflict and outlined some of the causes, but there has yet to be any in-depth research on how these conflicts are impacting on the management and use of reedbeds. 

CV: Andy Dodson MCIOB

2020-present Course leader, Built Environment, Solent University
2020-present Senior lecturer, Solent University
2019-20 Programme delivery manager, Chartered Surveyor degree apprenticeship programme, University College of Estate Management
2017-19 Unit leader, University College of Estate Management
2005-17 Clerk of works (construction), Royal Engineers
1997-2005 Plant operator mechanic, Royal Engineers
1996-97 Apprentice thatcher, Clive Dodson Thatchers

Given the age of current policy surrounding the use of UK reedbeds and requirements around stakeholder engagement for environmental land management payments, this will provide new insights.  

How wide is the gap between research and industrial application? How important is it to maintain the links between academia and professional practice? And how can we meet these challenges?

I don’t believe the gap is significant but the biggest challenge is effective dissemination of research. The majority of the industry aren’t reading academic journal articles or attending conferences so we need to look at how we can convey our work to those at the coal face so it can be utilised.

Academia does also need to remember that there is always an opportunity cost to trialling new ways of working and that, if it doesn’t work, it can cost a company a lot of money.

It is really important to keep the links alive so we can continue to support industry solving the broad range of challenges that it is facing.

How has becoming an educator helped you in your career?

I came into academia after 20 years in the Royal Engineers, so the past seven years have been a bit of a whirlwind. I initially came into education teaching Level 3 surveying technician apprentices, prior to becoming a programme delivery manager for the Chartered Surveyor degree apprenticeship and moving to Solent University just before lockdown, as a senior lecturer.

Now I’m leading all of the construction management, quantity surveying and civil engineering courses. It’s certainly provided a lot of opportunity for personal growth and development. You do have to be at the top of your game and you do need to be willing to be challenged. 

It’s been extremely rewarding, both in terms of educating the future of the industry as well as being a member of the trailblazer groups for both the construction site supervisor and construction site manager apprenticeship standards. 

While understandably there is a lot of focus at the operational level of teaching, you have to think strategically about the future needs of the industry, how you develop your courses to meet those needs and how you position yourself in the market. l  

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  1. Picture is of straw not water reed, which is misleading. Would be wonderful to see what research brings up, many reed beds in UK are now unmanaged but the distance imported materials travel should surely be a part of the case for bringing them back into production. Ecology is another issue for discussion. Labour cost is often a factor and the machinery which makes it easy to harvest is expensive, without it its hard work but not unachievable. Are you part of the thatching material research which is currently being undertaken, or is it just coincidence? Please stay in touch.

    • Thanks for your feedback on the article’s image, Karen. We have now replace it with a photo of water reed.

  2. This sounds very interesting and I hope the final research will be shared widely. Are you also looking at the life cycle carbon cost of reed thatch and comparing it with slate or tile?

    An interesting comparison is the Stone Carbon Calculator which has been developed by Historic Environment Scotland and is available free via The Engine Shed website (

  3. Definitely interesting however I know the less common type of reed for thatching was reed wheat, which tends to be more of a Southwestern thing and was looked on less favourably locally than water reed due to costs (despite it being expensive to the people having their roofs thatched, it didn’t seem worth the effort of growing as a cash crop when compared to convention wheat). However, I would be interested to see how it compared as well.

  4. As the joint owner of a Grade II* listed property, I attended the Listed Property Owners Club two-day exhibition in January of this year in London. At one of the seminars I attended, whose panel included a senior officer of English Heritage, an attendee asked this question: “My elderly parents live in a relatively small listed cottage with a thatched roof, and they need to re-roof the cottage. My suggestion to them was the potential to re-roof in reclaimed heritage slate, stone or tile, dependent on the local vernacular of the area. This would also would greatly reduce their insurance costs. Is this possible?” The senior officer from English Heritage was emphatic with his answer. “No, they have to re-roof with thatch!” The son was, quite naturally, greatly distressed with this answer and walked out of the seminar.

    Here is a potential idea for Andy Dodson: many companies produce plastic materials from recycled plastics, for example posts, flooring, cane, laminate flooring, roof tiles, etc. Would it a be possible for a recycled plastic thatch to be produced and secured to the roof for the first two or three layers, and then topped with real thatch? Andy, could you pose such a solution to English Heritage if you thought it might have some legs? The advantage would be longer life (I believe thatch has to be replaced approximately around every 30 years), and enable a more egalitarian approach for householders, or potential householders with lesser resources, to become custodians of listed buildings. It would be interesting to hear what your comments will be on this idea.

  5. Hi Karen,
    Thanks a lot for your message. Yes, I have been involved as a research participant in the excellent work being undertaken by Jenny Cheshire at Historic England.
    There are a lot of challenges in bringing reedbeds back into commercial production. I believe the biggest challenge will be updating policy surrounding reedbed management and Bittern. When the data sets were produced to establish ideal habitat there were a lot of limitations, such as the number of Bittern, number of Bittern sites etc.. The male Bittern population is now at circa 230 and over sites across England and Wales, despite only a small proportion of sites being subject to a special protection order. The blanket rules of leaving 2/3 of a large reedbed or that Bittern require 20ha in which to successfully nest need to be reviewed by bodies such as the RSPB.

  6. Hi Sara,
    Thanks a lot for your comment, and yes, once completed I do intend to make sure it is distributed as widely as possibly.
    I hadn’t planned on doing a like for like life cycle carbon calculation for slate or tile because it doesn’t really fit into what I’m doing but will take a look at The Engine Shed website because it could be very useful for comparing carbon of UK produced reed and imports.

  7. Hi John,
    Thanks a lot for your comment. I think there will always be a market for combed wheat reed because of the like for like policy, and how frequently used it is down in the South West. Historic England have also looked at issues around combed wheat reed supply in their research on supply of thatching materials, and it’s well worth taking a look at.

  8. Hi Andy,
    Thanks for your comment and I really do sympathise with the owners and their son.
    Straw will typically last between 20 – 25 years, combed wheat reed will typically last 25 – 35 years and reed upwards of 70, and even 100 with suitable maintenance! The ridge will typically need to be replaced between 10 and 15 years.
    There are types of synthetic thatch available, although I’m not entirely sure what materials are used in their production.
    From a thatching perspective I’m not entirely sure if what you are proposing would be feasible, although I will send the link to this article to my brother (who has 26 years thatching experience) and ask him to comment. I know aesthetically it doesn’t look that great. I would also assume that as it’s not 100% like for like material, then the chances of getting it approved on a listed building would be quite small, in a similar manner that you wouldn’t be able to use a synthetic slate on a listed property with Collywest slate.
    Personally, for situations like you describe, I think that it would be fair if there were a grant scheme available for re-thatching. You never really own a thatched property – you are a custodian.

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