Webinar on Retrofit and Flooding

00:00:01:00 - 00:00:25:19

Speaker 1

Brilliant. Thanks, Matt, and thanks everyone for coming today. It's so sunny, but I'm sure everyone wants to get outside. But we really appreciate you coming. My name is Joanne Williams. I'm a conservation accredited building surveyor who works in the climate change adaptation team at Historic England. Today I am joined by Ed Barsley from the Environmental Design Studio, and we're going to present a pilot study we've been undertaking over the last nine months.

00:00:26:08 - 00:00:54:13

Speaker 1

Just before I hand over to Ed, I just wanted to explain a bit why Historic England undertook the project. So water is a large part of our lives. We drink from it, bath in it, cook with it and we build with it. But it isn't until it causes an inconvenience to us that we really stop to think about water. As climate change causes rising sea levels, storm surges and unexpected heavy rainfalls, low lying cities, villages and towns across the globe are bracing for urban flooding disasters.

00:00:55:09 - 00:01:14:13

Speaker 1

Recently in the news we've been witnessing the extreme flooding events in Australia and Pakistan and we've also obviously seen the loss of the homes on the Hemsby in Norfolk after three meters, land fell into the sea in just two days. And predictions are actually suggesting that one in four buildings are at risk from some sort of flood event.

00:01:14:19 - 00:01:38:04

Speaker 1

It's important that when we think about solutions, we do this to prevent buildings from falling into disrepair and out of use. This isn't just in the UK, but across the world where across the world work is already being undertaken on a large or large community. Areas such as the Centenary Park development in Bangkok, which is on the left, which seeks to mitigate ecological issues, reduce flood risk.

00:01:38:13 - 00:02:01:23

Speaker 1

And it's also how to get the park to help the city reduce flooding, confront its climate change issues. And it offers city dwellers a place to reconnect with nature and reminds of the water, how it reminds the city how to live for water. On the right, you can see Rotterdam, which is obviously in the Netherlands, and this is home to the world's first floating dairy farm, which opened in 2019.

00:02:02:10 - 00:02:23:15

Speaker 1

It also has introduced floating parks made from waste and even a floating office building. But community schemes won't always be an option, and we might need to consider single buildings in isolation, as was the case with the building. We're about to discuss. Our ancestors knew how to make buildings resilient to flooding, and many of these measures still work today.

00:02:23:22 - 00:02:45:21

Speaker 1

However, the industry appears to have largely forgotten that traditionally constructed buildings are able to naturally dissipate moisture and wear sealed, tanked, damp, proofed or treated with sediment, tissues, mortars or gypsum plaster. This would not make the building resilient and in fact causes them to fall into decay and create health issues to the occupants. So the pictures on the slide are actually from my own home.

00:02:45:22 - 00:03:06:15

Speaker 1

I live in a 17 hundreds cob stone building that had previously had damp issues and was particularly cold in the winter, so the old tenant told me. Upon investigation, I found that the building had been tanked and various sections of carpet actually slept and were infested with rats. And yet later, I'm happy to say that my building is now drier, warmer and has no moisture issues.

00:03:07:12 - 00:03:27:15

Speaker 1

If you haven't seen the first webinar I did on flooding, we actually talk about the appropriate practices that you can do in place, and I'll post a link to that in the chat. I just also say pull out. So yep. Well, I've learned from working with Ed is that those of us adapting buildings need to start thinking outside of our silos.

00:03:28:02 - 00:03:59:19

Speaker 1

We have all got a duty to reduce our carbon emissions, to improve the energy efficiency of our buildings, and to ensure that buildings are made resilient. All climate change hazards where we fund specify, I construct or even retrofit. We need to think broader about the hazards the building might face and not just about improving its energy efficiency. This might mean in some situations as a society, we have to make difficult decisions about what is acceptable, better visual intrusion or loss of habitable space or an impact to our heritage.

00:03:59:19 - 00:04:20:02

Speaker 1

That is going to talk you through our work on assessing one particular house and building. We ask you to have an open mind to remember that our scenario has already happened to this building in question, and it's not something we are suggesting for all of the buildings at our handout. You and I look forward to seeing people's questions and thoughts in the chat, so enjoy.

00:04:20:02 - 00:04:48:06

Speaker 2

Thanks very much. And let's everybody tuning in. We're really excited to show you this study. It's been bubbling in the background and where I think it touches on some really pressing issues. So hopefully it'll be of interest. And as Joanne said, we're looking forward to people's questions as well. So just to set the scene, we focused this study on the village building, which is in the south east of England, and it's in the Medway Valley.

00:04:48:06 - 00:05:08:07

Speaker 2

This is the first phase of this of this research, study and building has flooded severely multiple times over the past two decades. In terms of why we've chosen it, it's got a range of different house types and construction materials. It's got a conservation area within it and many listed buildings in terms of its situation in the Medway Valley.

00:05:08:07 - 00:05:32:17

Speaker 2

It's a mid catchment position and any one of the three rivers that flow through it could flood its. So it is a it is a high risk area and large scale mitigation strategies have been deemed unviable technically and economically, economically to protect the village. Many options are being considered. And so what the residents of building are having to start to look at is what can be done to make the individual buildings more flood resilient.

00:05:32:17 - 00:05:57:19

Speaker 2

And the situation when when the sort of focusing and thinking about making these buildings flood resilient is that the Middle Medway Flood Resilience Scheme was undertaken and 304 homes were identified in the parishes as needing to be made more flood resilient. The issue and where we're focusing our study is that for 46 of these homes, so 50% of the properties, it was deemed that there was no standard measure for property flood resilience that would be suitable.

00:05:58:11 - 00:06:20:00

Speaker 2

So this was either due to the building's construction being a traditional construction, timber framed or issues relating to the listed status and conservation policy. So this read this rung some alarm bells because thinking, well, hold on, a lot of the buildings that slipped through the nets and missed out here were the buildings that we see in many different parts of the UK and around the world.

00:06:20:00 - 00:06:42:06

Speaker 2

And this that buildings that are actually I suppose when we think about how communities developed have been have developed near watercourses, there are areas that are now becoming much higher risk. And so we wanted to sort of zoom in and understand a bit more about these particular outliers, as we called them, and could be a factor figure, a piece of data, something that's different from the others in a set and doesn't seem to fit the same pattern.

00:06:42:06 - 00:07:06:09

Speaker 2

So we're focusing on these particular outlines. And the reason why it's important to consider is because actually with climate change, we're going to see many more of these being exposed and impacted by flooding and they could be damaged and start to fall into disrepair. The owners of these properties might find that they're unable to get a mortgage or insurance, and this could actually limit the quality and speed of repair and reinstatement to the wet.

00:07:06:09 - 00:07:26:09

Speaker 2

So they're getting the more inundations they're experiencing that could be damp issues that can escalate and cause damage to the building and ultimately to the occupants. Health, we could see house prices being affected as well. We selected these cottages, the case study for this initial phase one of the project as it's a grade two listed 16th century timber framed building.

00:07:26:22 - 00:07:51:16

Speaker 2

Now it's within the bounds of building conservation area. It has been flooded on multiple occasions and it's the home of Geraldine Brown, the head of the parish council. And Geraldine has been very proactive and in helping make the village a building flood resilient, she's been a sort of very well celebrated flood champion and helping encourage community resilience. But sadly, Geraldine's own house has had its troubles in finding ways to make it more full of resilience.

00:07:51:16 - 00:08:13:08

Speaker 2

So I think it's great to have been able to shine a light on that. And it was one of the buildings, one of these outlines that was excluded from the Middle Medway Flood Resilience Scheme. So the themes of interest in this phase, one of the study has been what has made the property an outlier, what the barriers to adaptation of these outliers were, how we might be able to adapt the actual building.

00:08:13:08 - 00:08:47:17

Speaker 2

How could we adapt Geraldine's house to make it more flood resilient, and what methodology we could actually use to explore and evaluate and ultimately communicate suitable strategies for flood risk capitation. And along the way, finding an opportunity really to. But whether there's any gaps in the code of practice for property flood resilience with regards to historic and heritage properties within the book I've written on the resilient design, there's lots of different strategies that are set out in terms of how we can make a property flood resilient, an existing building flood resilient as well as new build.

00:08:47:17 - 00:09:07:12

Speaker 2

You can see here in the red box with the arrow, that's those two strategies sort of picked out there. They're the resistance based approach and there's lots of different ways that we can make a building. Flood resilience resistance is about slowing the rate that water enters a building with with barriers and and and sort of sealing up or limiting water entry.

00:09:07:24 - 00:09:30:09

Speaker 2

And really that's what the the Medway scheme has been looking at. It's just primarily been thinking, well, can you fit a barrier on it, yes or no. And so as you can see, hit as many other options and many of the things that could be done to make a building more flood resilient. And this is going to look through here in session today and within the research project, within this study, we've looked at lots of different ways in which Jodi could adapt her home.

00:09:30:09 - 00:09:50:07

Speaker 2

And some of them might seem a bit radical, a bit the bit sort of they're pushing the envelope, but actually it's really useful to consider the impossible and work back from there. Consider what could be done and what the implications of different strategies could be, rather than just limiting and bottlenecking everything down and saying, Can you fit a barrier on that, yes or no?

00:09:50:07 - 00:10:13:23

Speaker 2

Well, if not, then we'll just have to leave it because there are many different things we can do to adapt. So we'll come through this, these strategies in a second, but you can see along the bottom there the avoidance and realignment based approaches include adding extra storage to the house or even lifting the building. And there are examples of actually those different strategies being underway in the UK and even in the actual village building.

00:10:13:23 - 00:10:40:19

Speaker 2

So about 100 meters from Geraldine's house, there's a property that has had an extra storey added to it and the ground floor has been changed to non habitable. So this is an example here where we're seeing vertical adaptation so that there wasn't any restriction given to the ridge height being changed and actually the plans allowed. This vertical adaptation of the building has been in touch with this house we're actually featuring in our next case study of hazard, an open flood resilient home.

00:10:41:14 - 00:10:58:08

Speaker 2

And Tim, who lives there, called me up a couple of years ago and said, we're surrounded by water, we're fine, we're safe. We don't need to leave the building. And that's a very different consequence than they experienced in 2013 when they were evacuated from the building and had to stay out for months on end when it was being recovered and reinstated.

00:10:58:08 - 00:11:24:15

Speaker 2

So we are already seeing different approaches to property, flood resilience being being acted on in the in the village. And this example here actually is a building, a five bed detached brick house along the River Thames that was lifted. And this property flooded. You can see the brickwork was was posing brickwork with cots and I-beam lattice slit in the structure was cross braced and computerized direct jacks gradually lifted the building.

00:11:25:06 - 00:11:48:00

Speaker 2

New foundations were put in. This strategy cost £80,000 to an act to undertake, and it doubled the house price. So the house price went from 1 million to 2 million because ultimately its exposure to flood risk was reduced here. So the thresholds are higher. I'm not saying we need to do this with every property or in every single place, but it's very interesting to see the different strategies that are out there and could be considered.

00:11:49:20 - 00:12:18:15

Speaker 2

There are even examples where people have built new build extensions next to Heritage Properties and we can see here the Wildfowl Cottage extension by fifth studio in Cambridgeshire as it's next to an old pub, I believe. And it's actually positions that finish for a level of the new building is positioned up above the future flood datum. It's single clad, it's it's kind of a, you know, a safe haven, an escape, an additional habitable area if the other building floods.

00:12:18:15 - 00:12:51:24

Speaker 2

So there are examples out there that we can we can reference already where these different strategies are being undertaken. Now, when we think about the next method, just to talk you through the different thinking of the method that we've used within this study, the code of practice for when I say PFR, that's Property Flood Resilience recommends a range of criteria to be considered in stage three, which is options development and design, and that's that includes performance, the time for construction, how easy something is to maintain the suitability for the end users needs and cost.

00:12:52:07 - 00:13:16:05

Speaker 2

So I think many of those are sensible and we thought, okay, that's a really good starting point to work from. But within the research I've been doing in the Retrofitting Resilience Study and and actually focusing on yielding in particular a number of other criteria that sort of have been raised, this ones to consider. So that's the building's exposure and vulnerability, the actual consequences of what would happen if a building was flooded.

00:13:16:23 - 00:13:48:06

Speaker 2

And crucially, I suppose for this audience in particular, its impact on significance with regards to the building's heritage. But we also wanted to understand actually what the occupants of occupancy levels were in the building and how those are affected over time as well as the wider benefits of the buildings from a particular strategy for the occupants. So if we start thinking about flood exposure and vulnerability, those have heard me talk before often say just because of buildings exposed to flooding, it doesn't have to be vulnerable.

00:13:48:06 - 00:14:12:14

Speaker 2

And the example on the left here, you can see this matrix of exposure versus vulnerability. A houseboat might have a very high exposure to the water to flooding, but actually because of its set up and design and high adaptive capacity, it's got a low vulnerability. And in contrast, a building halfway up a hillside could have quite a low exposure to flooding, but actually be quite vulnerable in terms of its materials and sets up.

00:14:12:14 - 00:14:36:17

Speaker 2

So it might not take much for flood water to cause a lot of damage in that building itself up the hillside. And as we know, flooding doesn't only happen from rivers in the sea's surface water. Flooding is a huge problem and can cause devastating issues. And so I think it's important to disassociate and and sort of understand the relationship between exposure and vulnerability and not just now, but what it could be in the future.

00:14:36:17 - 00:14:58:14

Speaker 2

So we've been thinking about this with regards to Geraldine's house. We've also talked about the consequences of the flood. So actually when the building floods, can the occupants remain in the building or are they out for a significant amount of time? A lot of existing assessments and reviews for flood risk and resilience. So thinking about does the building flood yes or no?

00:14:58:14 - 00:15:19:21

Speaker 2

But there's a lot in that gray area in terms of where the building might have flooded, but it's been made recoverable. People can get back in in a very quick amount of time with minimal impact in a couple of days, weeks or hours. And so actually it could have minimal consequences. And again, I think this granularity and specificity is really important to consider.

00:15:19:21 - 00:15:39:12

Speaker 2

So as you can see here, we thought about how to visualize this and how to show this impact on occupancy. And for flood during a flood after a flood week, a month, three months, six months. I'm thinking about when we've heard from Jody and she said, oh, well, we lived upstairs temporarily with a with a sort of a small self, temporary kitchen.

00:15:40:04 - 00:15:55:23

Speaker 2

We were up there for six months and then we were able to, you know, after a couple of months, we were able to move a few things back downstairs. And so the reality of it is many people are out in temporary accommodation, but a lot of people do choose to to stay in the building, to stay within the area, in the community they know.

00:15:55:23 - 00:16:21:06

Speaker 2

And so these buildings are being inhabited and lived in in very disrupted states. And, you know, the press and the media might move away, but it can still take a long, long time for a community to recover, to be fully functional again, and the end user suitability. So in speaking with Geraldine interviewing her, we've also heard about the experience of the different floods, but also how Geraldine and her husband would like to live in the house moving forward and then the future.

00:16:21:06 - 00:16:39:13

Speaker 2

So if they lived upstairs with that temporary kitchen and after the two flats, they've experienced that. As they get older, they don't want to be doing that. They don't want to be in this state of sort of perpetual disruption where it's never quite how they want. And once things are back to normal, it feels great. But as they age, they don't really want that disruption.

00:16:39:13 - 00:17:03:24

Speaker 2

And again, these are really important issues to consider as well as the heritage values. And so one of the things we've looked at is, is these the three themes or three values of architectural and artistic interest, archaeological interest and historic interest as the sets out in the NPPF. So many of you will be familiar with this. And I think it's a really interesting lens to assess the different designs, strategies that showed you earlier against.

00:17:04:11 - 00:17:29:19

Speaker 2

And what we did is we've been using something called multifactor analysis to work with and review each of these different criteria. Many of you will be aware of lots of criteria, analysis, but essentially it establishes preferences between options by reference to an explicit set of objectives, decision making, what is identified and for which it's been established, measurable criteria to assess the extent to which objectives have been achieved.

00:17:30:13 - 00:17:49:10

Speaker 2

So in terms of how this has worked in our projects, we had that quite those criteria and those different themes that we just showed you, and we then created a waiting for that. And so the expert group working with Historic England on this and we've run a number of different design workshops around this, we have a waiting to each different criteria.

00:17:49:10 - 00:18:10:11

Speaker 2

So in the example below, accessibility is 50% that actually we think accountability might be a bit low. I mean, that's not to say that we've used this for those for this particular one, but what it allows you to do is to tweak and adjust sensitivity for different criteria. And each strategy is then scored and then you have a results which considers the score in relation to its particular weighting.

00:18:10:23 - 00:18:35:10

Speaker 2

So it allows you to tweak and adjust and tailor to suit the specific stakeholder and occupant as well as context. So we run this workshop with Historic England. It was really exciting, some fantastic discussions about the different options and what the ramifications might be and which which which particular approach might be most most suitable. And and the weightings that came from this.

00:18:35:10 - 00:19:02:24

Speaker 2

So again, you can see here, this is the range of criteria we considered and we had different associated weightings with these. Now the way it works up to 100, it's essentially a the weighting is multiplied against the score. So the ease of construction wasn't the question, but necessarily is the indicative costs and so on, so forth. We also want to think about actually how we communicate the consequences and how we communicate the outcomes of all of this scoring.

00:19:02:24 - 00:19:31:01

Speaker 2

So I'm not going to go through this particular slide right now in detail, but in the report that we'll be releasing shortly all about the study for every single scenario, we've actually pulled together this kind of dashboard page, which shows the resulting score for each criteria. And it's a really useful way, I think instead of this information being spread out over pages and pages and difficult to kind of comprehend for each strategy, you have this dashboard page that you can really get your head around and read in more detail.

00:19:31:01 - 00:19:50:14

Speaker 2

So that was the set up in the method that we've used to actually consider the appropriateness of those different strategies. When we think about Yalding and in Geraldine’s house, it as I said, it's got three rivers flowing through through using the Medway tees, the river belts. This is a view across the floodplain. That's right next to Geraldine's house.

00:19:51:23 - 00:20:19:17

Speaker 2

And the property is at risk of flooding from rivers in the seas, quite low surface water, flood risk. And it's got high flooding from central reservoir breaches. We've got two reports as part of the study that's been shared with us by Landmark Information Group. And again, there, it just sets out actually that there is moderate to high risk of flooding from the river and there is significant future flood risk as well.

00:20:21:04 - 00:20:42:18

Speaker 2

Now, in terms of Geraldine's experience in the House in 2000, Geraldine flooded in the year 2000 and they'd been in the home for about 20 years. The water apparently was full of raw sewage and stank. It took eight months for them to actually recover in which they stayed temporarily. Upstairs, the lounge floor was very slow to dry out and it cost the insurer roughly £75,000 to reinstate the building.

00:20:43:14 - 00:21:07:02

Speaker 2

And in the 2013 flood it was deeper and reached the top of the fence outside, but actually the water appeared cleaner and it didn't sound like it had as much sewage contamination and more raw sewage in it. And it took in that occasion, six or seven months for the property to be reinstated and recovered and cost roughly £85,000 for the insurer to reinstate.

00:21:07:02 - 00:21:29:16

Speaker 2

So again, over these two floods, you can see there's been a huge amounts of money spent to actually reinstate the building with only minor improvements being made in terms of whether it is more flood resilient. Now, what really at this moment in time now is that flood response in build back better. And when a building does flood this £10,000, that can be put towards making that building more more resilient improving its property flood resilience.

00:21:30:09 - 00:21:50:16

Speaker 2

This wasn't the case at the time, but certain changes to be made to the kitchen and Geraldine's house and other measures of raised sockets that have improved its resilience, but not significantly. So there is still there would still be significant damage caused flooding again so that that 2013 flood level came to the top of the fence just outside Geraldine's house.

00:21:52:08 - 00:22:09:03

Speaker 2

And when we think about the properties set up, it's all this part of the building was shown on the map of 1545 other major parts of built in about 1800s. And in 1989 they raised the cat slide roof at the back of the house. The building that you can see actually is built up on a bit of a plinth itself.

00:22:09:03 - 00:22:28:22

Speaker 2

So it does it does infer that actually when it was originally built, people were aware that it needed to be raised up its timber frame structure. You can see that sort of the the rear side of it is the extension there. And it has been changed around significantly over the years just through we have a 3D tour of the house.

00:22:28:22 - 00:22:46:19

Speaker 2

If anybody wants to scan the screen and click and move around it, we did a 3D scan of the building. And so, again, that gives you a good, good flavor and understanding of the type of setup of the particular building. And floodwater can really answer this in a variety of different ways. So it could come in through the front door, there's an oven.

00:22:46:19 - 00:23:11:09

Speaker 2

The water appeared to have entered from surface entry points. So drainage, different drainage, inlets and outlets, even the side doors up through the windows, through the S and floor in the lounge, by the external walls themselves, because that's in the frame. So and up through that the timber framed floor suspended timber frame flow and then you extension. So with this building there's lots of different ways in which the floodwater could enter it and did enter it.

00:23:12:17 - 00:23:38:10

Speaker 2

So we then move on to considering different design options. And as I said, we've been thinking through some of the different ones which might be suitable and sets out a range of different strategies. So there's 14 different scenarios that we've considered here and scenario one and two, really thinking about recoverability of what can be done if the building floods to make it so that it can be reinstated and sort of back to its back to its former status.

00:23:39:09 - 00:23:55:11

Speaker 2

The second two are about resistance, which as I said, were part of the sort of the way of thinking within the Medway flood resilience scheme and then really scenarios 5 to 14 to thinking through about a range of different avoidance based approaches. So I'm going to go through each of these different strategies just to flag the ones that we've been thinking about.

00:23:55:11 - 00:24:11:20

Speaker 2

And then at the end of the talk, I'll show you some of the results that we've come up with. So the first scenario was to say, Well, actually, what if you did nothing? What if you just said, let's just wait and see, let's leave the property as it is. And so really, this is our baseline benchmark of understanding what could happen.

00:24:11:20 - 00:24:33:19

Speaker 2

And and we know that flood risk in the village is planned to increase. This is potentially going to increase in the coming years. And so at the moment, Jody and her family are relying on flood risk insurance to reinstate the building. And again, they live with the temporary kitchen upstairs. If it floods, you know, with this heritage property over time, it will keep getting damaged, keep being impacted.

00:24:33:19 - 00:24:52:23

Speaker 2

And this is in this area of the estate that we want to see. So thinking through about its occupancy, you know, actually when the flood does happen, Geraldine’s upstairs with that temporary kitchen. And after months and months, eventually they're back into the building. And in the future, we're likely to see is actually that their property is uninhabitable.

00:24:52:23 - 00:25:16:15

Speaker 2

And this is disrupted functionality for a longer period of time. So actually, if they if these floods start to occur more frequently and more severely, then they could be caught in this period of recovery for a lot more time. So the second thing is to say, well, actually, what if you change the floor and in the lounge area, which was very slow to dry out and actually lengthen the recovery process and that is something pumps.

00:25:16:15 - 00:25:34:20

Speaker 2

So you try to make the building more recoverable. So you try to reduce that 6 to 8 month recovery time they had it. So if the water comes in, it's sort of inundates the building. But actually you can set it up in a way to get it back up and running quicker. And that seemed to make a lot of sense.

00:25:34:22 - 00:25:59:08

Speaker 2

The sort of the pros and cons, you know, it's it's inhabitable quicker. The cons are that actually as flip that's increase over time and frequencies increase. It will keep getting flooded and you know that it'd be living in a disrupted state for a longer period of time. The third scenario considered the resistance measures. So barriers and this is really what the Midwest scheme was looking at and it could help actually to slow the rates of water entry.

00:25:59:08 - 00:26:23:12

Speaker 2

But because of the build up of the property and the different multiple entry points, we saw that the floodwater could be actually moving through those walls. And with the actual structure, we don't want significant, hydrostatic and hydrodynamic loading on the building itself. So whilst it's an option to consider, we consider saying, well, it's not particularly suitable in this context and larger scale version is to consider perimeter protection.

00:26:23:12 - 00:26:41:10

Speaker 2

And actually, what could you do? Could you or could you build a much larger but larger structure of flood wall with flood gates around the boundary of the site and in this particular context, it might be that it needs to run around the perimeter of multiple properties. And again, with this strategy, we've got to consider what the tipping point is.

00:26:41:17 - 00:27:03:02

Speaker 2

How high do you go with this wall? What where does the water get pushed? That was being that's being excluded. What happens if rainfall folds inside the barrier and actually if the property floods from within? So again, each of these strategies, there's consequences and things that we need to review alongside them. The strategy well scenario five is to think about converting the attic.

00:27:03:02 - 00:27:25:18

Speaker 2

And so actually not vertical adaptation, convert the attic and change the ground floor to non habitable scenario six is to say, well, what if we lifted the building? What if it's already on a plinth of sorts? What if we actually raise the building up above that future flood level six scenario was say, well, so in the seventh scenario say, well, actually, what if we reconfigure the floor level?

00:27:25:18 - 00:27:46:13

Speaker 2

So from the outside of the building, the set up looked, looked sort of the actual outline of the building's form was kept reasonably similar, but within the building we changed and shuffled and reconfigured the floors. This one's really not very favorable in terms of the damage to the set up inside the building. But again, we're thinking through all these different options.

00:27:46:13 - 00:28:04:05

Speaker 2

The eighth scenario is to consider actually what if we out of the next story, as Tim has done about 100 meters away in the village, add an extra storey to the property and change the ground floor to non habitable. Now, as you can see here, what this does is it really changes portions of the whole building. It doesn't look like Geraldine's house much anymore.

00:28:04:05 - 00:28:33:09

Speaker 2

But again, it in terms of the consequences of the floods, Geraldine would be able to say upstairs with a continued functionality. And I'm saying that perhaps scenario nine is to think about adding an extension. So actually, what if you did a bit like Wildfowl Cottage in Cambridgeshire that we saw and an extension could be tucked away behind behind the primary elevation and it's a new build elevation extension, sorry, raised up above that future flood level.

00:28:33:09 - 00:29:06:03

Speaker 2

And it's an area that could be designed to be low energy of appropriate materials, clad in the appropriate materials. That's actually when Geraldine's property does flood, it's somewhere that they can still continue to live in and living in that in a suitable way. Scenario ten was to say, Actually, what if you lifted the building and added a recoverable ground floor so the ground floor could be built of materials that are actually quick and easy to hose down and reinstate after a flood without your original setup of the building was lifted.

00:29:06:18 - 00:29:32:07

Speaker 2

So they continue to be able to access and use that ground floor zone in this scenario. And scenario 11 was to think about making it amphibious. Actually, you can position the building on an amphibious deck and as the floodwaters arrive in building, the building would float up. It would have flexible services in the set up, and it could even be raised up before the flood using mechanized electronic jacks and after the flood, the buildings lowered back down.

00:29:32:07 - 00:30:00:14

Speaker 2

So again, we're considering many different options, but there are examples around the world of where people are retrofitting existing buildings already to make them amphibious. So again, this is approaches and technology that's already out there. Scenario 12 is to say, okay, well, what if we lifted or move the building to another location? Actually, we see this when many parts of the world with or with coastal erosion where light has to move, different buildings are picked up and moved to scenario 13.

00:30:00:14 - 00:30:20:20

Speaker 2

What if we dismantled the building, rebuilt it in an alternate location? We see this in in different areas where, for example, a reservoir might be created and some of the particular heritage buildings are dismantled and rebuilt. And in living museums and in different places where they can be studied and preserved. Scenario 14 is so okay, let's just knock down the building.

00:30:21:15 - 00:30:40:04

Speaker 2

This buildings, this, this property is being impacted and damaged by floodwater. What would it be if you just knocked it down? And clearly this is not the perfect option, but again, it's viewed and thought. So we're comparing it to these are the range of different strategies. So I think it's really interesting to think through all the different options in the scenarios.

00:30:40:04 - 00:30:59:23

Speaker 2

But one of the things that we found with the results and you can see here, this is looking through the lens of the heritage values and it's showing you each of these 14 scenarios. Now, on the right hand side, they're not the building down scenario of 14. That's clearly not preferable. It's coming out as the worst. It's alarm bells ringing.

00:30:59:23 - 00:31:24:02

Speaker 2

It's it's showing that the high score here is harmful, low scores good. And actually, things like reconfiguring the floor levels that require that would require a huge amount of disruption to the internal set up of the property. That scenario eight adding an extra floor to the building was deemed to really be significantly altering the actual its architectural form, disrupting its historic value.

00:31:24:02 - 00:31:47:07

Speaker 2

And so that didn't score very well. But again, it's interesting to think through these different options and what the ramifications and implications were with regards to heritage values, but also consequences. So here it while some of them scored very poorly with heritage values, we can see here actually that the consequences of the floods for scenarios one, two, four was was was not great.

00:31:47:07 - 00:32:08:16

Speaker 2

And so actually for some of them, there was a tipping point where it didn't score too badly. For example, scenario four in the current condition with perimeter. But in the future, actually, there could be severe consequences. So I think this approach is useful to consider and review what might be a short term solution or strategy and actually what the long term implications might be.

00:32:09:09 - 00:32:37:02

Speaker 2

Because flood risk is going to increase significantly in this area. So we don't just want to be silting and thinking of a strategy which is going to work for about ten years. You need to think of these longer term options. And so finally thinking through all the different multi criteria scores, we've got the overall results shown here. And what was quite interesting actually was that the two that sort of scored lowest were to cut the building and lift it and also to think about making the building amphibious.

00:32:37:02 - 00:33:19:21

Speaker 2

And obviously that's sort of technology led solution approach. But what it's really doing is thinking about reducing and changing the exposure of the building. So it's flood risk exposure and increasing that adaptive capacity or actually just positioning it up out of the way so it's not going to be harmed anymore. And lifting the building was, I suppose in the discussions we had, it's not significantly altering the the set up of the building above that's above its plinth level is there is some disruption to its kind of its base area in the archeology, but you're not getting a building which is constantly being inundated with flood water and being having dehumidifiers chucked in heaters, dryers and

00:33:20:07 - 00:33:41:20

Speaker 2

the building be made to dry out. So I'm reducing a lot of the impacts on that particular property. So in terms of the next steps and sort of things, we'd love to have to discuss with you all about the second phase of this study, just to sort of update, everybody will be looking at much more detail about the costings associated with each of these particular strategies.

00:33:42:10 - 00:34:10:17

Speaker 2

We also want to understand what the carbon emissions would be and when we think if I just jump back of each of these different strategies. Actually the Aviva report that was recently released, recently released showed the difference between the vulnerable and the resilient building was essentially the equivalent to 6.5 transatlantic flights or think 13.9 tonnes of carbon. And so when we see actually the costs 75 or 85,000 every time building Geraldine's house floods to put it back together.

00:34:11:07 - 00:34:31:08

Speaker 2

Well, if it's going to flood another couple of times in the following decades, then you're looking at quite a few hundred thousand that have already been spent to reinstate the building. And so actually maybe there were some approaches which have a larger upfront cost but smaller lifetime costs. And there are lots more of carbon emissions. And we're also going to be considering the access and egress to the buildings.

00:34:31:08 - 00:34:54:05

Speaker 2

So actually, some of them do require first floor level access. And we need to think through how that could be done and what might be suitable and also what the visuals are. And so actually what design would look like it as part of the streetscape and would it been like to live in the building on that? Really the third phase of this study is going to test this approach on two different building typologies and in relation to a number of different types of flood risk.

00:34:54:05 - 00:35:15:05

Speaker 2

And so we're considering terraced housing and coastal properties. So if anybody's got some suitable ones, fantastic, could be got in touch. And then to really expand and enhance on the multi criteria analysis methodology that we've been using here. So I'm, I hope this has been of interest really keen to hear any questions that anybody would have. And yeah, hopefully we can open up some fantastic discussions that.

00:35:15:05 - 00:35:37:02

Speaker 2

Thanks very much for listening. Ed, thank you so much for that blistering presentation. I should add we do actually have the the poll if you'd like to. Oh yeah. That can be accessed through the poll. Let's do that. Yeah. So we were going to ask this just before we did the big reveal and look through the different strategies and the results.

00:35:37:02 - 00:36:07:05

Speaker 2

But which of the 14 PFI scenarios for this property do you think would be identified as the most preferable from the NCA process? Now I suppose what would be good for people to do is think about showing you the results now, but actually be interesting to hear which ones you yourselves might think would be suitable. And I can see here live updating scenario three is being shown as a strategy, but actually resistance measures aren't highly aren't particularly effective for this particular property.

00:36:07:05 - 00:36:18:17

Speaker 2

So it's, you know, it's a kind of a go to approach thinking about, okay, let's use resistance, but actually we've got other other ones popping up here. That's really interesting to see.

00:36:19:15 - 00:36:37:04

Speaker 1

I think the interesting thing is the fact that the PFR we worked up with the height of the window is with the flooding. Is that actually a barrier on the door would have got overtopped or it got to the point it would have structurally made the building structure unsound. And it gets to a point you should have opened the door.

00:36:37:24 - 00:36:45:01

Speaker 1

That's another reason the PFR kind of came in as being a bit, you know. Yeah, it might work for the next couple of years, but actually it's probably not going to work.

00:36:46:05 - 00:37:04:14

Speaker 2

Yeah, that's such a good point. Actually, the barrier could almost end up trapping the water in and causing more damage from the water being trapped in for longer. And so that's something that we also considered and I think you're right, there are with all these different resistance measures, there are tipping points and thresholds at which they're going to be exceeded.

00:37:04:23 - 00:37:13:01

Speaker 2

So the barriers may well help to slow down some of the smaller floods. But as you say, yeah, the larger ones in the future, floods would ever top those.

00:37:13:11 - 00:37:32:03

Speaker 1

But it also requires, if we think about the fact this is a heritage building where it's, you know, the front door was a pretty good condition. We weren't going to consider putting a flood door in, so it would be a barrier. You'd also have to have Geraldine there. So that's one of the big issues with the barrier approach is that actually if your person's on holiday, no one's necessarily there to protect your building.

00:37:32:08 - 00:37:43:02

Speaker 1

And in the case of Geraldine, actually one of her big issues was groundwater flooding. So when you try and mitigate against that with PFR it's a completely different ballpark.

00:37:43:21 - 00:38:03:12

Speaker 2

Mm hmm. Yeah. And that that was linked in to the long term saturation of the of the lounge in there. So the soil there as well. So I think it's interesting to consider the strategies that can help speed up that recovery process because, you know, that's that's from the sounds of it, what kept them out of their homes so long or kept them living temporarily in their home for so long.

00:38:04:11 - 00:38:19:02

Speaker 1

And it's a fascinating one, isn't it? Because obviously there was a lot of discussion about looking at community perimeters to protect the entire village. But obviously, they actually they found it would have impacted other villages down the way, didn't they? Yeah.

00:38:19:06 - 00:38:33:04

Speaker 2

So that was going to push the problem elsewhere, which again, we can't do everywhere. And I think the thing to remember with all of this is actually that we were just looking at this in the in relation to Geraldine's particular house, I would say the most dangerous thing we can do is to copy and paste the strategy from one place to another.

00:38:33:04 - 00:38:49:02

Speaker 2

So it might be some of these strategies are interesting to consider in other contexts, but in this particular context it wasn't it was actually a large scale perimeter protection in the village with would flood quite a few other homes and so that wasn't necessarily deemed ideal.

00:38:50:04 - 00:39:08:24

Speaker 1

And I think is that thing isn't it about buildings is you know like we said I said at the beginning one in four buildings are at risk of some sort of flood event. And we've already seen you know, if we look at Great Yarmouth for Norfolk, they've got extreme flooding going on with high sea level rising predictions. By 2030, most of Yarmouth's going to be underwater.

00:39:08:24 - 00:39:25:14

Speaker 1

You've got the Living With Water project that's going on in Hull at the moment because they're in a similar situation. And it's one of those things that you kind of, you know, may not did this work because. We started going, well, what are we going to do with these buildings? Even if it wasn't a heritage building, if it was just, you know, normal buildings?

00:39:25:14 - 00:39:47:03

Speaker 1

Port Isaac, for example, 700 new houses that flood. You know, we can't move everyone and we can't continuously lose the embodied carbon that sits in these buildings that are someone's house. And, you know, they're not going to get any money from it to move it like they do in America. So this was just really just try to go, well, what can we do to actually help these people a bit more?

00:39:47:03 - 00:39:52:10

Speaker 1

What can we do to protect these buildings, particularly as the heritage? And yeah.

00:39:53:13 - 00:40:25:17

Speaker 2

And I'm just saying some of the questions that are popping in the chat there's, you know, actually people are saying if we are thinking longer term, making individual buildings flood resilient doesn't make the village suitable for continued inhabitation. That joined up approach is really important and actually thinking beyond the property scale. And one of the things I've been doing in the Retrofitting Resilience study was to look at actually how you could retrofit the whole village to make it flood resilient and that was including walkways that people could continue to walk around and move on when when the water when bits of the village in a village are flooding to 1.5 meters deep.

00:40:26:13 - 00:40:51:13

Speaker 2

So I do think we need to think you're absolutely right. That's an ask the question about thinking about connectivity between the different buildings and, you know, this whole source pathway receptor. We need to see what we can do beyond the property to reduce flood risk and within community resilience and catchment scale strategies. But in this particular context and for this property, we would just for this very, very initial phase one of the study thinking about what could be done to this particular building.

00:40:52:08 - 00:41:08:16

Speaker 2

So as I said, phase two is to think about access and that could be something that links into continuity for the village as a whole. And I'm feeling actually, it's it's the historic part on one side of the of the river that is flooded in this uphill kind of goes up and there's lots of houses up there still.

00:41:08:16 - 00:41:29:13

Speaker 2

So parts of the village are still inhabited and there's lots there's disruption to some areas and not to others. And so, again, it's it's contextual at that. We need to look at everything through that lens really. And I can see that Kirsty's asked the question about any solutions here, specifically because of the building's age or conservation status, because of the depth think sense of flooding.

00:41:30:17 - 00:41:56:10

Speaker 2

PFR measures, I suppose your point about PFR measures do have limits if water is above a certain depth, I suppose if a property floods its products. I would say because property flood resilience is when we're looking at thinking about raising floors, adjusting things. Those are part of the suite of approaches for property flood resilience. Yeah. And products do have limits, I would say.

00:41:56:10 - 00:42:18:18

Speaker 2

But we've still been thinking when the report comes out, you'll see a lot of the details and discussions and sort of conversation analysis we've put in for each of the scenarios and we have very much been talking about this and thinking it through in relation to the buildings, age and its conservation status. So we've just haven't been able to cover every single thing in this short webinar, but the report will have a lot more detail if you.

Have any studies been undertaken for historic industrial sites?

Historic England has worked with historic industrial sites at risk of flooding but these have yet to be written up as case studies. There are plans to look at the adaptation and resilience of historic industrial heritage against flooding as a wider project for this year.

Was heritage consequence of flooding and reinstatement evaluated?

Yes, the impacts on heritage from the perspective of flooding / reinstatement was considered and discussed as part of the MCA process and workshop.

Was there any project control used along with the Matterport to tie it into National Grid etc.... ?

There has not been, but it would be an interesting approach to explore in further phases of the study.

Could you consider using a sump pump within the barrier (Scenario 4)?

Yes, this is included as part of the suite of measures for scenario 4.

Aperture and perimeter barriers seem to be the only alternatives to do nothing for tenants. How can landlords be incentivised to reduce flood risk in properties they own but don't occupy?

FloodRe and other professionals are currently discussing this in line with new policies and commitments coming out from government.

Am I right in saying any of the solutions here aren't specifically because of the building's age or conservation status, but because of the depth and extent of flooding - current and future?. PFR measures do have limits if flood water is above a certain depth and duration

The solutions are specific to this buildings age, construction and heritage significance and shouldn’t be seen as a copy and paste solution for other buildings. The criteria the scenarios were assessed against were used because of the buildings age, use, construction and heritage significance. If the building had been constructed of different materials it would have had a different existing resilience to flooding. 

Is there a project for how to contain sewage in flood zones?

An interesting question, ‘containing’ is a specific approach and management question really that needs to be considered at catchment, community, street and building scale. There is plenty of focus and attention on reducing the volume of raw sewage that is released into water ways and the ocean as well as the frequency at which this occurs. At the building level, non-return valves can help stop the back flow and surcharge of a drainage system. Other strategies are discussed in the Hazard and Hope episode on ‘What makes up flood water?’.

Is there are geospatial management plan to bring forward (capture, use, and filing thereafter) all spatial data for such projects in a consistent manner?

At this moment in time we’ve not explored this, but it would be useful to consider for further phases of the study.

You have studied water but is wind not a corresponding study given that storms typically deliver both?

Wind is certainly a topic that Historic England is exploring and research is being undertaken.

What measures might be taken for UNESCO protected buildings/ areas that do not want to lose their status?

Each buildings needs to be assessed by its own merit and not one solutions suits all. For larger more complex buildings its possibly that a variety of solutions will need to be considered. In addition, the context of where it is sighted and the amount of stakeholders with an interest needs to factored in before designing any measures.

Interesting to hear how some 'helpful' interventions can actually backfire and cause more harm if not context appropriate. For this site, what is the time line for deciding which method to select?

There is no time line, the site is a purely a pilot study working with the home owner whom may decide to invest in one of these scenarios or not. The home owner knows that the house will be subject to more flooding.

Did you consider financial feasibility for occupants/building owners? Or is that a later phase of the project? Were there options that might be preferable for Geraldine's property that would be ideal but were just financially prohibitive for her so had to be discounted?

Resourcing a Quantity Surveyor to undertake calculations for doing the work is part of phase 2. Who finances the works would need to be a conversation with the owner and her insurers.

What mechanism are you using to predict increases in water level, wind speeds and duration of the environmental change. when do you judge the 1 in 100 year climate event to be the 1 in 5 year climate event?

We are not currently looking at future wind speeds, but this can be considered in further stages of the study. For this portion of the research we’re considering climate change allowances for flood risk from the Strategic Flood Risk Assessment for the area (collated by Arygll Environment in their flood report) and via the Environment Agency’s product 5 and 6 datasets.

Could you explain a bit more about the scoring methodology please. How did you arrive at the weightings? Are they specific to this building or are they equally applicable to others?

The weightings were specific to this particular building and collated by the expert panel in conjunction with the homeowner. As this study develops, we’ll be testing the method in other contexts. The weightings help make the decision making more site specific, as in different contexts people’s preferences and the building’s setup/risk profile can vary significantly. The method is explained in detail in the report that is soon to be released. You can find out more about MCA process at the government website.