A Little bit about me...

I'm a Structural Engineer, specialising in conservation, at Hurst Peirce + Malcolm in London. I don't wear tweeds, am not particularly "cultured" and I'm not that old, but I do care passionately about the conservation of old buildings. I am a Chartered Structural Engineer, a member of The SPAB (formerly on the founding committee of the reborn Berks, Bucks & Oxon Regional Group), a Friend of SAVE Britain's Heritage and have recently completed a PD Diploma in conservation at West Dean College, with a view to achieving CARE accreditation. I hope to give you regular updates on my trials and tribulations as well as some insight into projects I am involved with and things I believe in.

Be patient with me - I'm no writer and I'm normally up to my eyeballs at work........

All views expressed here are my own.

Hurst Peirce + Malcolm, Celtic House, 33 John's Mews, Holborn, London WC1N 2QL

07854 624692 - richardsalmon9@gmail.com

Monday, 21 May 2012

Conservation Engineering for Engineering Students

You can thank students for this one. In particular, Charlotte Illsley ( @Concrete_Geek )

As far as I am aware, in the UK, right now, there is no mainstream education for budding building conservation professionals below post-graduate level, and no mainstream education in conservation engineering at all, so how on earth can young (and not-so-young) engineers get interested in this 'branch' of structural engineering (unless you are lucky enough to be working at one of the handful of practices that specialise in conservation)? I know this is something that Andie Harris (HSI/NECT) is looking into and hopefully something will come of it. A good start would be for universities to offer an optional module in refurbishment and conservation.

Well, I thought I'd help out by doing a 'bitesize' version of my first blog post and by coming at it from a slightly different angle for a different audience.

I had always taken Conservation Engineering to be a 'specialism'. This is still the case, since you can become 'accredited' in it and good on you if you are. You have proved yourself against a rigorous assessment process with your aptitude and experience. This accreditation enables you to work on major/capital projects for clients such as English Heritage, The National Trust and projects funded by HLF and the like. But (and I speak from a personal perspective here) there is no middle ground, no stages, no mid-term assessments. You are either accredited or you are not and then there is always the catch-22 of getting the necessary experience in order to become accredited if your firm does not have 'pedigree'.

Thinking about it from another angle, should it really be a specialism practised by a limited 'elite', or should it be a another tool in the box of every engineer? Clearly there are pros and cons both ways, but the current system means that one can remain fully ignorant of what is involved unless one goes specifically out of ones way to find out. This invariably leads to insensitive treatment of non-capital (lower grade and unlisted historic buildings, which still require the same level of care), where no specific conservation credentials are required. But lets leave that discussion for another day.

So, back to the point: What is Conservation Engineering? What makes a good Conservation Engineer?

The most important thing in my opinion is to be passionate about old buildings, how they were built, their history and saving them as a legacy for future generations.

Secondly, as there is no specific training as such, you need to be able to fully understand and appreciate conservation philosophy and then adapt your 'conventional' engineering skills to put that philosophy into practice. The modern definition of conservation is 'managing change' and the engineer will use his specific skill and experience to respond appropriately to any changes with minimal detriment to the historic or architectural significance of the building in question. In my book, this means doing nothing to the building unless you need to.

This is easier said than done. Even though a building may have quite happily stood there working for hundreds of years any changes/alterations to, or degradation of, the building fabric, plus changes to building usage or external/internal environment can break that fragile equilibrium. There are also 'business' factors to consider, such as insurance/risk management.

So, lets try and boil this down by taking a simple example (to keep this post to a manageable length), say an existing timber spine beam, approximately 200 years old and an original part of the building. A change of use will result in a change to the existing loading regime:

Firstly, we survey, collecting all the data we need to enable assessment: Sizes, span, deflections, species, condition (rot, insect attack, splits, shakes & twists, etc - utilising specialist surveyors if needed) - as hopefully, any engineer would. But after this, the 'conventional' (new-build) engineering approach diverges from the conservation path.

Design codes go out of the window. Old buildings were not designed to Standards but from experience handed-down by generations. We make an accurate assessment of what dead and live loads are likely to be, rather than plucking a figure out of the loading code. We use simple analysis to determine stresses and strains in the beam and then use our judgement to determine whether those stresses are too high or not (these cannot be compared to modern grade stresses as old timber is known to be much stronger than new) using working loads only (no place for factors of safety here, unless we judge that some extra bunce is necessary). If there is any doubt over the capacity of the beam, then load testing can be carried out in-situ to verify assumptions, particularly useful if you want to try to determine Young's Modulus. Repairs and/or strengthening, if deemed necessary will be considered in such a way that the conservation tenets are adhered to (conserve as found, minimum intervention, like-for-like, reversible, sympathetic) with a presumption that repair is always preferable to replacement, unless there are exceptional circumstances. Traditional carpentry timber repairs are also preferred, as opposed to introducing alien materials, but again this may not be possible if loadings/stresses are too high. We also quite often have to come up with more than one solution to a single problem in order to give the client or architect a choice. They like that.

The strengthening of an original oak beam using a central vertical steel flitch plate (invisible from below apart from where timber plugs cover recessed bolts). Strengthening was required in this case due to a significant case of wet rot damage at one end.
I hope this has given you an quick insight into the world of conservation engineering and that a few of you might take it a little further. Please do not hesitate to get in touch if you have any specific queries.

Some recommended courses:
The SPAB's 5-day 'Repair of Old Buildings' course, run twice a year.
'The Structural Repair of Historic Buildings' 3-day course at West Dean College, by Ian Hume and Terry Girdler.
Individual courses run by The Weald & Downland Museum, Essex County Council and others.

Some Recommended reading:
"The repair of Ancient Buildings" AR Powys (SPAB)
"Structural Repair of Traditional Buildings" by Patrick Robson (Donhead)
(Quite old now, some repairs involving cementitious materials, etc now out of favour)
"The Repair of Historic Timber Structures" by David Yeomans (Thos Telford)
"Structural Aspects of Building Conservation" by Poul Beckmann & Robert Bowles (Elsevier)
Numerous papers written by Ian Hume for The IHBC and Buildingconservation.com.
"The Repair of Historic Buildings" by English Heritage
"Appraisal of Existing Structures" by IStructE

PostScript: So, it appears that a handful of universities offer some sort of optional module in conservation. I would like it to be more. I should also mention the IHBC route to accreditation, a valid alternative for engineers too.


  1. Really interesting blog. Thank you for the insight. It doesn't seem as scary as I thought it would be. :)

  2. A good read Richard. I am currently on a post-graduate route towards conservation accreditation. I agree there is no recognisable route for Conservation Engineers and as a subject it isn't covered at all at undergraduate level or on engineering post-graduate degree courses.

    Engineering is such a broad subject and although it would be good for all engineering graduates to have a base knowledge in conservation and repair I'm not sure what could make way to allow this to happen. Conservation is a mindset, a change in philosophy, it affects how you approach every project and unless it is something you are personally interested in I don't know how you could imprint that mentality in the mind of young engineers. You also need to have an interest in old buildings, how they were built and why there were built and an understanding of building pathology.

    Like you say, Conservation Engineering is a specialism; you need the engineering academic base to solve the problems but the conservation mindset and some lateral thinking to take a suitable approach. I expect it would be a tall order to come up with an undergraduate degree course in conservation engineering that didn't dilute either the engineering or the conservation and already a post-graduate level qualification is required to become Chartered.

  3. Charlotte,

    Thank you for your kind comment and thank you for planting the seed. This was something I had wanted to talk about for a while but hadn't found the right angle.


    Thank you for your comments. I suspect you are right, as I have had this discussion with one of my directors who is currently on the ICE/IStructE Joint Board of Moderators, but we need to consider any and all possible educational opportunities in order to spread the message and hopefully avoid unnecessary damage to our less well protected built heritage.

    As a p.s. - I have been advised that the University of Manchester now runs an undergraduate module in Conservation of Structures, run by Tom Swailes (with thanks to Brian Duguid)

  4. My course (under-grad) at the University of Bath included an optional 'Conservation' module. It was run by Dr D D'Ayala. Sadly it could only give a brief insight into the field due to time pressures. However, it did give students sufficient exposure to whet their appetite, to perhaps persue it further.

  5. Hi Scott,

    That is good to hear. Another one to add to the list. And it should be easier, especially for places like Bath, which already run engineering degrees and conservation masters courses, to run a little something, even if not a full module, as a way of raising awareness.