Lime Green turns 21

LG21 Jonathan Garlick from SPAB Q&A

What has been the most important change in the protection of ancient buildings over the last 21 years?

It has to be the changes we helped implement to building regulations in 2010, that came about around discussions for the Green Deal.   The government at the time had approached mainstream insulation manufacturers but we felt that older buildings needed a different approach and called for more research.  As a result and with the help of Historic England, changes were made and special considerations added to Building Regulations approved document Part L that remain there today.

It states that a building which is vapour permeable can only use insulation materials that absorb moisture but they must also allow it to evaporate.

The changes allow building control to understand that old buildings are different and that they need to be treated differently and says how what types of materials should be used.


How long have you been in collaborating/working with Lime Green?

Really since 2010 when the Green Deal was being looked at.  With the help of various organisations, Lime Green being one, we met with government over our concerns and James Ayres was involved in the research undertaken as a precursor to the Part L changes.

James’ house was one of the buildings we monitored for a few years after the changes.  Looking at the figures before and after he installed the Warmshell system, it turned out to be one of the most efficient we observed.


What makes Lime Green a suitable supplier for the kind of projects/campaigning that you are involved with?

They understand old buildings full stop.  James, who I speak to, is incredibly knowledgeable.  His background, his knowledge, particularly in lime is immense.  With woodfibre, he’s been there, tested it, used it, understands it, so there’s a good level of trust in Lime Green, which makes life easier. You know they will make a good call. 


Could you give us any examples of projects, we may not know about, that have used Lime Green?

I’ve used the exterior Warmshell system on my own house.  The house was built in 1958 and in 2016 we added an extension.  It was a no brainer really, I had the evidence it worked, trusted Lime Green, it has a BBA certificate which meant building control could sign it off easily.

It’s proved to be fantastic.  We have 450mm thick walls and 500mm roof.  We don’t have heating on in there at all and it’s a lovely environment to be in, winter or summer.

We’re also using James at The Old House Project, a 15th century converted chapel that as an organisation we are renovating.  James has been involved in the lime research and we also have permission to insulate the building so are looking to use Warmshell for that.


James at the Old House Project at our Boxley Working Party.


What’s the most pressing issue for ancient buildings going forward?

It’s the conundrum of wanting to ensure that old buildings are fit for the 21st century with regards to energy efficiency. Using the right materials but also not destroying their character.

It’s the importance of not using inappropriate materials that fail and have to be taken out.

The right material may alter the building in some way but will add to the historic fabric to the building, and like we can now, people will see our work in hundreds of years’ time.  So it’s not always about preserving something in exactly the same state, in aspic as it were.  We need to preserve but accept materials move on and they are all part of the evolution of the building.


As we’re celebrating 21 years in business, what advice would you give to any 21-year-olds looking to make a career in your sector?

I speak to a lot of 21-year-olds who are interested in building conservation and the best advice is:  get onsite and get your hands dirty. Get familiar with the right materials and learn from great people – craftsmen, surveyors and engineers.  Everyone who works in conservation knows we need great new young people and as a result many really welcome any young person.  Organisations such as The Princes Trust and apprenticeships are great too.

Get your hands dirty, pick up the materials, feel them, you get a huge amount from handling the materials.


Our thanks to Jonathan for taking part in this Q&A.  If you would like to find out more about SPAB visit 

Photographs of Shakespeare's Globe courtesy of Artisan Plastercraft and Chris Taylor. Photographs of the British Museum courtesy of Artisan Plastercraft.

 Cover photo credit: Ralph Hodgson. Photograph of James Ayres courtesy of Jonathan Garlick.

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