Don't Bat Away Sustainability Issues

There was a brief period in the mid-2000s, during my time working in architectural practice, where it felt like I was becoming an expert on bats.

I was a long way from being an expert on bats, of course - to suggest otherwise would be to do conservation experts and bat specialists a great disservice. But I had the opportunity to work on a couple of projects featuring bat protection, and it was an interesting area to explore.

Preaching to the unconverted

Both projects were barn conversions in Cheshire: the buildings to be renovated were habitats for bats, and provision needed to be made for them before any work could start.

Plans for the first barn included a brand new, detached double garage. The first floor was intended as a play room - a play room that had to be sacrificed once the bat survey yielded its results. The family found themselves still paying for a substantial brick-built structure on its own foundations, but with an upstairs that I designed and detailed solely for bats and not for them or their kids.

You can probably imagine the disbelief with which the idea was met when it was first suggested.

The second project was more straightforward but no less interesting: the site featured a suitable location, near to hedgerows, to accommodate a small shelter specifically for the bats that had been observed inside the barn. Unsurprisingly, since they weren't losing living space, the reaction from this client was a lot more favourable...

I was happy too, for not only could I expand my experience of designing conservation features for bats, but I could also enjoy the simple pleasure of calling it ’the bat cave’ - even if ‘bat house’ was a more appropriate description!

Boxing clever

Sadly, my experience of thinking about and designing for bats progressed no further after that - they didn’t feature on any more projects before my career switch to insulation.

I had cause to be reminded of it recently, however, when I found myself in conversation with a representative from the Bat Conservation Trust. She wanted to know how incorporating bat boxes - like these - would impact on the installation of cavity wall insulation, particularly high performance rigid foam boards.

Since the boxes are all designed to fit standard 102mm wide brickwork, happily the answer was simple: there would be no impact at all. The boxes do not encroach on the cavity, meaning no impact whether the insulation is partial fill or full fill, rigid or flexible.

Cavity wall insulation may seem complex to some specifiers and installers - particularly new generations of products - but this is an excellent example of how biodiversity features can be incorporated in the fabric of new buildings with little or no alteration to the design or construction.

It may be the best part of a decade since I worked on bat habitat designs, but I do remember orienting openings to steer the bats in particular directions when they exit the building - so I suspect all that is needed with these bat boxes is a little bit of expert advice to help determine the most appropriate elevation on which to site them.

Newt-onian principles

While my work on bat habitat designs may have stopped after those two barn conversions, I did find myself dealing with another protected species for a while: newts.

I suspect many people think of newts halting work on large developments, but they are every bit as likely to be found on smaller sites. As my knowledge built, I increasingly found myself becoming aware at an early stage of ponds and other site features that could be a home for newts.

It was important to spot the potential because surveys of newt habitats, like many biodiversity surveys, including for bats, can only happen at certain times of year; much better to warn a client and commission a survey in advance than risk their ire as a planning application got delayed because of a lack of forethought. Inevitably, there was a cost associated with that, but better to be safe than sorry.

At least, that was my thinking. On one project, my boss preferred not to draw attention to the issue. ‘We’ll worry about it if they [the Local Authority planning department] ask for it,’ was the thrust of his argument. I’m fairly sure there was also an element of wanting to make the planning department the scapegoat if and when delays and additional costs were incurred…

Long term benefit

I glossed over the reaction of the clients whose play room turned into a play room for bats rather than their growing family, but there was genuine - and understandable - dismay on their part at having to make the compromise. It’s not that they weren’t willing to accommodate bats on the site, it just happened in a way that none of us had foreseen - and which cost a lot of money for no tangible benefit to themselves.

And there, in a nutshell, is the problem: biodiversity and the preservation of protected species is so far down people’s list of priorities that it either shocks them when it becomes an issue, or they prefer to ignore a potential issue in the hope that it doesn’t become one.

Protecting biodiversity is not just red tape, though; it’s not planning departments being difficult for the sake of being difficult. It’s about minimising the already significant impact of humans on the earth, protecting animals and habitats from those who would otherwise concrete over them at a moment’s notice.

Like trees that have Tree Preservation Orders attached to them, and which ‘just happen’ to be brought down by a bad storm, some people are only too happy to look for loopholes, shortcuts and escape routes to free themselves of their obligations and concentrate on short term gain.

That’s what made the conversation about bat boxes such an enjoyable one - it is a relatively simple measure that, with a bit of forethought from those planning and designing developments, can go some way to mitigating the impact of building more new houses.

What the industry needs then, I would suggest, is more conversations like mine: more education, more often, on a bigger scale, highlighting how we can not only build sustainably, but also ensure we continue to enjoy a rich and diverse natural environment around us.


I recently wrote about how valuable the House Planning Help podcast has been to my construction knowledge, so it would be remiss not to draw attention to an episode about biodiversity that is well worth a listen if you are interested in this topic. It taught me things about the building materials we talk about and use every day, and how they relate to animals like bats, that I simply wasn’t aware of.