Is it Time to Bring Back Thatched Roofs in British Architecture?
Finding a thatched roof in this day and age is a rarity. However, on a blissful weekend away in the rolling hills of Sudbury, Suffolk, IGOLO’s founder Sophia spotted an array of thatched roof cottages. Sophia began to question sustainability of thatched roofs, and how we may be able to apply them in modern architecture.
With increasing pressures being placed on designers and architects to take climate action, the use of natural materials has grown in popularity. While some materials remain hidden, others such as cob and hemp are fighting their way back into the mainstream. Is the thatched roof a suitable solution to the climate crisis?
Countryside wheatfields in Sudbury
What are thatched roofs?
A thatched roof is a traditional roofing method which uses straw or reed to provide shelter as well as an additional layer of natural insulation. In comparison to hard roofs such as slate or composite tiles, thatched roofs are considered to be more eco-friendly due to its source and regenerative nature.
One of the most pressing challenges of building a thatched roof is sourcing all of the appropriate materials. Historically, architecture was built using natural materials found in the local area. Now, with our dependency on imports and modern farming techniques, the materials appropriate for thatching are much harder to come by. The straw from wheat, oats, and rye are much shorter in length and are thus unsuitable for thatching. Therefore, thatchers often grow this long-stemmed straw themselves- they are woven, combed, tied, and cut around the eaves.
With energy prices rising and colder weather right around the corner, additional insulation is desired by most in the UK nowadays. Thatched roofs can provide a suitable solution, due to the insulative properties of straw and reed.
Building regulations often require roofs to have a U value of 0.18W/m2k, whereas thatched roofs sit between 0.29 and 0.23 W/m2k at a 300mm thickness.1 U values indicate how much energy can pass through a square meter of a barrier when the inside and outside temperatures differ by one degree. Using a thatched roof even without additional insulation comes extremely close to meeting modern requirements.
Why are thatched roofs on the decline?
Thatched roofs have been on the decline for about 200 years, ever since slate and pantile became readily available. They seem pretty ideal on the surface until we begin to examine their disadvantages. Before you go and hire a roof thatcher, consider the cons list below.
- Modern fire regulations. Thatched roofs are only allowed on detached buildings with a minimum of 12m distance from the site boundary. However, this distance can be reduced if certain fire barrier levels are met in the build up. This is why thatched roofs are only really seen in rural settings.
- They are expensive and tedious to maintain. Roof thatching is a highly skilled service, and this is reflected in the price. In total, you can expect to pay anywhere around £15,000 to £30,000 for a thatched roof. You may need to shell out extra costs for your thatched roof too, such as netting to deter nesting birds and pests, and fire retardant protections. You will likely need to spend money annually to maintain your thatched roof.
- They require annual inspections. You will need to have your roof inspected once a year to make sure it’s up to scratch.
- Prone to wear and tear. The ridge cap of your thatched roof will need regular maintenance. Leaks are the most common issue here, which can cause serious damage to other sections of the roof.
Should thatched roofs make a come-back?
There are plenty of pros and cons of thatched roofs, and in a time where insulation is desired by many, they seem like an ideal and sustainable solution to these issues. In many ways, however, thatched roofs may cause more trouble than good. With their expensive costs and need for regular upkeep, you may find that a thatched roof is more trouble than it is worth.
This may explain why thatched roofs are on the decline and are only really found in rural settings today. They were a natural solution historically, providing much needed insulation using materials from the local area. This is why thatching is so prevalent in conservation initiatives in particular.
Considering the latest innovations in modern architecture and design, perhaps it is most practical for us to leave thatched roofs in the past. However in a world haunted by climate change, thatched roofs may be the sustainable switch we need to consider to put another foot forward to save our planet.
Modern examples of thatched roofs
Contemporary Interpretation of a Traditional Zagorje Cottage by PROARH Architects, Kumrovec, Croatia. Copyright PROARH.
Doggerij by LEVS Architects, Don Helder, The Netherlands. Copyright LEVS.
1 - https://historicengland.org.uk/images-books/publications/eehb-insulating-thatched-roofs/heag079-thatche d-roofs/