Architectural Measures to Reduce Overheating

We will be talking about architectural measures which have been used to reduce overheating. But, first of all, we just wanted to give you guys an introduction to Thread. So, Vanessa and I work at Thread, a specialist conservation architecture practice based in Somerset. Our approach places great importance on thoroughly researching the evolution and significance of the historic buildings and sites we work on, often saying that the building will tell us what to do. Our team of nine have a diverse set of specialist skills, and through collaboration, open-mindedness, and robust questioning, we work on a wide range of projects including industrial heritage, art galleries, museums, and cafes.

Our architectural work involves considering the ongoing sustainability and methods for future-proofing historic spaces, so they remain relevant and functional for the communities that use them. This was a great opportunity to focus on how we will need to adapt existing buildings to suit the changing climate. Historic England commissioned a report to identify historic architectural measures that can demonstrate and support England's historic buildings in adapting to the changing climate. We set out to investigate how passive architectural measures such as awnings or shutters have been used in the past to reduce solar gain and seasonal overheating. Our research has not been limited to shading devices, but considered both historic and contemporary passive architectural measures.

Most of England's existing buildings have been adapted with a focus on reducing heat loss, but what impact does this have on people's comfort as climate impacts intensify? Historic England also wanted to understand the risks and limitations that might prevent the implementation of potential passive measures and how these risks could be addressed. This research follows the publication of Historic England Advice Note 18, adapting historic buildings for energy and carbon efficiency, and we hope will inform development of Historic England's suite of guidance on overheating and historic buildings. It also relates to activities within Historic England's corporate plan and climate change strategy, and to commitments made in the government's Third National Adaptation Program, NAP3, and we'll be providing a few links at the end of this presentation. But before we jump to the...

Oh yes, sorry. So, during this presentation we'll identify some key terminology and the mechanisms by which climate change will increase overheating. We'll summarise our literature review and list the passive architectural measures which we identified have been used to reduce overheating. Risks and limitations which need to be considered when undertaking these types of retrofit project have been identified. A matrix has been produced which plots the architectural measures against risks and limitations.

Three case studies where passive architectural measures have been retrofitted to existing historic buildings are shown at the end of the presentation. Our full report will be available on Historic England's website. But before we jump into the rest of our presentation, we should probably define a few of the terms we've already mentioned. What are passive architectural measures? These are physical features designed or retrofitted to improve the internal comfort of a building by working with the local climate to reduce the demand for mechanical heating or cooling systems.

In contrast, active or mechanical services are systems installed in a building such as air conditioning, heating and ventilation, which require a source of power for their operation. Overheating occurs when internal temperatures increase to a point where occupants may experience discomfort. It may be caused by internal heat gains from mechanical and electrical equipment, people, or from external weather conditions. So, what are the range of climate change predictions, and how is it anticipated that the change in climate will cause overheating? Hours of sunlight will remain consistent, but increased levels of greenhouse gases will insulate the Earth's atmosphere and trap the Sun's heat.

Cloud cover is expected to reduce, increasing levels of solar radiation. Changes in wind patterns could reduce availability of natural ventilation. Weather predictions are variable due to the complexity of calculations, and small changes to input data cause large changes to the predictions. This particularly relates to humidity and moisture. Summers may be hot and humid, or hot and dry.

Proposals must be robust and appropriate for both scenarios. In cities, the urban heat island effect is expected to increase and exacerbate the issues above. This is caused by increased thermally massive surfaces, decreased areas of greenery, and improved surface water drainage, reducing the effects of evaporative cooling. Our first task was to undertake a literature review to find and compare what has been written about historically used passive architectural measures, with an initial focus on England. We know that in Victorian England measures to promote natural ventilation were designed and promoted primarily in public buildings such as libraries and halls, which were prone to overheating due to high levels of occupancy and the heat emitted by gas lights.

This gave rise to the invention of patent roof ventilators. Hendrik Schoenfeld has been researching the natural ventilation and cooling strategies used in prominent buildings such as the Houses of Parliament and the Crystal Palace. Perforated floors, stack ventilation to pull hot air up and out, and night purge cooling were all used in the 1800s to help solve the issue of overheating. Louvres were also used to provide natural ventilation to buildings such as dry houses, dyeworks, and factories. Once a common feature of the English high street, awnings adorn shopfronts and buildings to provide adjustable shade whilst allowing for breeze to flow through.

Climate change experts predict that England's weather will become similar to conditions historically experienced in the Mediterranean region, namely warmer, wetter winters, and hotter, drier summers, as shown in the UK CP18 climate projections for the UK. So, we knew we needed to look more closely at what has been done historically to suit the Mediterranean climate. In Greece, we find the hayat, a semi-open covered living space, typically found in 19th century domestic buildings. In Sardinia, this translates to the loggia. In Cyprus, The semi-open structure can be seen in the form of pergolas and vine-covered structures.

Each of these measures help to provide shade and more constant internal temperatures to improve comfort for their occupants. In parts of Italy, the use of white lime wash on its vernacular buildings demonstrates the tradition which stems from the need to reflect the hot sunlight to help cool the buildings. Today, we find a variety of cool paints and solar reflective coatings which have high solar reflectance values and thermal emittance values. Traditional timber shutters, solid and louvered, have long been used as an effective technique to cool Mediterranean buildings. Today, contemporary options such as aluminium roller shutters may offer improved thermal performance, but often lack the character seen in their historic counterparts.

Our study found other techniques such as overhangs, balconies, cross ventilation, and night purge ventilation. Night purge ventilation involves opening windows or vents at night to allow cool night air to replace hot air inside a building. Numerous studies have shown this is one of the most effective ways to achieve summertime cooling. This project also identified the opportunity to learn from the passive techniques used by British colonial architects and builders in overseas territories, where they implemented British building design but adapted it to suit the hotter climates. The late 19th and early 20th century saw the increased use of industrially produced materials, as they were found to be ideal for withstanding hot weather, storm conditions and termite attack.

For example, mass produced cast iron detailing and corrugated iron sheathing were easily transported by ship to the Cape, South Africa, resulting in its prolific use in the region, which experiences winter rainfall, unlike the rest of Southern Africa and Mediterranean weather conditions. Many features were intentionally designed into colonial buildings to suit the hot climates, rather than being subsequent adaptations. They have been included in our report, as they provide precedents for possible retrofits to existing buildings using design styles and features which could be deemed sympathetic to a large proportion of the historic building stock in England, and potentially the wider UK. Ventilated pitched roofs, deep eaves, ventilating turrets, towers, and cupolas were distinguishing features of British colonial buildings in hot climates such as Georgetown, Penang, and India. They were not only ornamental, but provided passive ventilation by drawing hot air up and out of the building.

Similar features can be seen in the architecture of German colonial buildings in Namibia. Many buildings made use of a basement or suspended floor not to provide cooling in itself, but used together with open windows at night. The basement could store cool air collected overnight to retain cooler temperatures indoors, as external daytime temperatures soared to 25-30 degrees. A key feature identified is the stoep or veranda. This performs a similar role to the Mediterranean loggia or hayat, providing a covered outdoor, semi-open living space that helps to cool and shade the interiors.

In South Africa, the stoep can be seen in the Cape Dutch buildings, on the old wine estates, on shop fronts, and on domestic properties throughout the country, both new and old. While the verandas or stoeps which developed in South Africa were often built of timber or cast iron, materials widely accessible from Britain, German architecture and subsequently German colonial architecture, did not make use of cast iron features to the same extent. German settlers found that timber was highly susceptible to attack by termites in the hotter, drier climate of Namibia, and therefore made use of clay brick to construct their verandas, developing a style unique to its other African counterparts. German colonial architecture developed in response to the climate, bringing the Verandenstil, or veranda style, to domestic and administrative buildings. The early German settlers were encouraged to construct the verandas all around a building to prevent rain and direct sunlight falling on the walls.

Verandas not only took on the role of the hallway, but also became a significant extension of a house's living space. In most cases, buildings did not only feature a veranda but demonstrate a variety of passive techniques to help with cooling. A combination of awnings, deep eaves, and a ventilating turret, or the combined use of a veranda, wooden shutters, and roof ventilation. The use of several architectural measures in each of these buildings provides them with a unique and rich layering that adds to their architectural interest. We also looked at literature on modern architecture, which was frequently adapted to suit local climate conditions.

Tropical modernism in West Africa, for instance, illustrates the use of brise soleils, louvers, and wide eaves, taking European design to suit local conditions. In India, it has been found that vernacular, pre-colonial, and colonial architecture demonstrates the use of semi enclosed spaces for outdoor living, veranda corridors, chajjas, or sunshades, jali, lattice screens, and glazed clerestory windows, all of which avoid or reduce the use of mechanical cooling. Our review found that a lot has been written about achieving thermal comfort in buildings without mechanical cooling, mostly through theoretical modeling of contemporary methods and construction types, and less through recording of existing building scenarios. In many cases, thermal comfort was assumed to be related to protecting against heat loss rather than avoiding overheating. It was, however, helpful to extend the literature research to contemporary passive methods to understand where some of these might be appropriate within the historic building context.

So, some of the measures listed are not necessarily historically used, but rather ones that have been found to be effective. Following the literature review, we categorised the passive architectural measures which have been used to reduce overheating into three distinct categories. These categories respond to the mechanisms by which climate change will cause overheating. Shading measures will block solar radiation. Installing natural ventilation measures can maximise air movement for comfort, making the most of any available wind, and provide opportunities for purge ventilation to reduce humidity overnight.

Surface and material applications can be installed to block solar radiation and increase the solar reflectance of materials, which in turn could reduce the urban heat island effect. It is likely that a successful project would employ several of these measures to reduce overheating rather than relying on only one. Our research has not specifically addressed the potential impact any measure may have on the heritage significance of historic buildings, although our report does mention some of these considerations in the descriptions of the measures. Under shading, we found the following possible measures. Awnings...

Sorry. Sorry. Overhangs or deeper eaves. This is, of course, a bit more difficult to retrofit in historic buildings without altering the existing roof structure, and may have considerable visual impact, but the use of an extended porch roof or secondary roof structure could offer similar shading to the ground floor. Balconies, verandas, stoeps, or loggias, vertical fins or slats, brise-soleils or screens.

This could be a vertical fixture placed in front of the windows to provide shading. They could comprise louvres, mesh, perforated metal, or patterns. External louvres or shutters. External roller shutters. These commercially available shutters have become widely used in countries such as Germany or France.

Their use may be appropriate in certain circumstances, but does require careful consideration in terms of their visual impact. Internal blinds, trees, planting, or green walls, these offer the benefit of evaporative cooling to help lower temperatures. The use of deciduous plants means that in winter their leaves will fall, providing improved day lighting when it is most needed, with denser shade in the hotter months. Reduction of window to floor ratio. This is one of the most effective measures to reduce the risk of overheating, but does increase the risk of damp and condensation if ventilation is reduced too much by this change.

And deeper window recesses. Of these methods, external shading devices have been found to be the most effective method of reducing solar gain before it enters a building. We have also noted that solar shading should be used in combination with nighttime cooling or night ventilation to achieve thermal comfort. Ventilation measures include alteration of fixed windows to openable windows, openable clerestory windows, which is a design strategy used in many new build projects in hotter climates. This allows for secure nighttime purge ventilation.

Ridge ventilators, towers, turrets, or cupolas. Increased ceiling height. This has the added advantage of enabling the installation of a ceiling fan, which, although it is mechanically operated, is a low-energy means of creating air movement inside. And surface applications include surface colour, a relatively low cost change to help lower the temperature of the building, solar reflective paints or coatings. Cool paints have a high solar reflectance index or albedo effect, and are often applied to roof tiles and rendered walls, to be used with care, with consideration of moisture transport mechanisms and reversibility.

And UV-absorbing and or solar reflective window film. The replacement of existing glazing with UV or infrared reflective glass may also be a solution where the loss of the existing glazing can be justified. And now, we'd like to know: which of these measures have you successfully used in your building, specifically to reduce overheating? We'd love to hear now. A poll is going to appear.

And if you scroll down, you should be able to see all of the possible measures. So, that's quite interesting. Quite a few people have used overhangs and deeper eaves. and awnings. A lot of internal blinds as well.

We'll give you a few more seconds to add in your... A lot of internal blinds. That's really interesting. That's great. If everyone has added in their vote, we could close the poll in a few seconds.

Thank you very much, everyone. So, we are now going to talk about our evaluation of risks and limitations for each of the architectural measures. But first, in relation to the projects that you just shared with us in the poll, we would invite you to share any key limitations or issues that you experienced during the design or installation, and how these were navigated. So, interestingly, it seems like a lot of people had used internal blinds, which would be a much more common thing for people to install than, say, external blinds by themself, I suppose, on a DIY level. So, as we are talking through the risks that we found, we'd just be interested to find out any key experiences that you had as well.

So, we have reviewed the measures against various risks which relate to construction projects in England. Documents which we consulted to identify these risks include the approved documents of the building regulations, construction, design, and management regulations, health and safety welfare regulations, and health and safety and executive guidance. Other aspects considered include fire safety, thermal comfort standards, passive house principles for occupant comfort, and anticipated changes to England's weather due to climate change. Risks were sorted into categories. If a risk could be categorised into more than one place, our document will explain where it can be found in the risk matrix.

The categories are: climate hazards and impacts, such as extreme weather events, cost, sustainability, program, and maintenance, occupant experience. So, people must be able to confidently engage with measures if user input is required. Health and safety, quality of intervention, and legislation. So, this slide gives you an overview of the matrix which will be available to you. And this plots each of the architectural measures against the identified risks and limitations.

The matrix intends to give building owners and managers a helpful overview of potential risks and mitigation measures to help in deciding which options are appropriate for your building. So, across the top you've got all of the architectural measures which we just ran through, and along the side you've got the risk categories which we discussed, which go into much more detail. And these are mapped together. If you were considering installing awnings, you would find the awnings on the top row, and then look down the specific risk levels in that column for each of the risks along the side. The subjective scores have been identified through collaboration with a collective of individual professionals and Historic England.

Risk has been scored from one to three, low to high risk, and is a factor of likelihood and severity. A zero in the table identified that there is no risk as the architectural measures would have no interaction with this risk. UV-absorbing window film would score zero for wind loads as this would have no effect. Plus in the table identifies architectural measures, which could be beneficial and are extremely low-risk. Roller shutters would score plus for security, as they could be used to protect against break-ins.

The matrix is available in a single page or separated into a document for shading and a document for other architectural measures in an attempt to make this more user-friendly. Both versions include an explanation of specific risks and things which could be considered as part of the mitigation strategy, which you can see on the screen here. This is a zoomed-in version. Taking the example of an awning, you can see that this has the highest level of potential risk identified in relation to wind. A building owner or manager considering installing a measure to provide solar shading in a location with high levels of wind could use this table to identify alternative options which would be less at risk from wind damage, or review the mitigation considerations to start making a strategy for managing this risk.

Given the nature of existing buildings, risks must of course be reviewed and considered on a case-by-case basis. The matrix presents the highest possible level of risk, meaning individual projects are likely to start with lower actual risk levels. The value of identifying these risks at an early design stage is that they can then be mitigated and managed throughout the project. The suitability of architectural measures will depend on existing construction, character of the building, character of the measure, use and occupancy type. For example, in public buildings, there may not be anyone who feels empowered to move shutters or curtains, meaning they do not fulfill their function.

The location of the building can also make a big difference on the suitability of interventions. Sites have different levels of exposure to weather, as well as latitude affecting the preferred dimensions of shading elements. So, the diagram on this page illustrates the variation in external shading dimensions required to fully shade a window at midsummer between areas in the furthest north and furthest south of England, assuming that all other elements are consistent. We then searched for projects to illustrate where these architectural measures have been successfully and effectively introduced or retrofitted to historic buildings. The search was limited to retrofit projects involving commercial or residential buildings that are listed or within a conservation area, which could be supported within accurate measuring and monitoring data collected before and after installation.

Jerez de la Frontera is a city in Andalusia, Spain, which has been recognised by UNESCO for its intangible cultural heritage, including its continued tradition of Sherry making. The historic medieval center consists of a tightly-woven network of historic buildings and narrow streets. Many of the buildings include traditional wine cellars or bodegas, constructed with thick whitewashed walls and high ceilings to ensure constant temperatures. Traditionally, many bodegas have been kept cool through the use of vine arbors known locally as emparrados, which helped to shade the interiors with their deciduous leaves. The Gonzales Bias winery pioneered the expansion of the emparrados in the 1960s by planting more vines throughout the streets of their winery on Calles Llegos in Jerez.

Building on this tradition, a pilot project entitled Songs of Nearby Earth was developed to regenerate lost sustainability wisdom through nature-based solutions. Since 2024, 4 streets have been planted with vines to provide shading and cooling to more buildings across the city. The city of Jerez hopes to extend planting to 20 streets. The selected vine variety, vitus riparia, does not produce many grapes, minimizing fruit flies and sticky fallen grapes on the paving. A single vine can be trained up the side of a building and across a trellis of cables to provide a horizontal canopy of up to 60 square meters.

The roots do not cause damage to adjacent buildings as they penetrate the ground vertically. We spoke to project partners Estelle Julian and landscape designers Nomad Garden, who explained how the collaborative project brought together students, gardeners, ceramic artists, composers, and even the luthiers who make the traditional zambomba, a ceramic friction drum made using the ashes of the pruned vines. The local council agreed to dig holes in the city's pedestrianised streets to accommodate the new vines, which were planted by local volunteers. FabLab Jerez fabricated a monitoring system to collect temperature and microclimatic data. This found that temperatures were reduced by up to 10 degrees in August 2025.

Nomad Garden have noted that this technique has worked well in Jerez because of the low humidity levels of the area, and the vines' effect of evaporative cooling. Success may be more limited in areas of higher humidity, as the presence of the vines increases the humidity of the space below them. Additionally, as the vines grow in density, their summer foliage may reduce the natural ventilation of the narrow streets below. More monitoring is needed as the vines develop over time to understand their optimal use in differing street contexts and scenarios. The project provides a positive example of how learning from traditional practices of a place can offer culturally rich opportunities for climate adaptation.

Our second case study is the Erasmus building, which is located within the Grade Two registered park and gardens of Queens College within the historic core conservation area of Cambridge. The building, designed by Sir Basil Spence, was built 1959 to 1961 and inspired by Le Corbusier. Providing student accommodation on the top three levels, these rooms are also occupied by visitors to conferences during the summer. The building was overheating due to several factors, including heat gain through uninsulated elements, solar gain through single glazed unshaded windows on the south and west facades. Hayson Ward Miller Chartered Architects worked with Joel Gustafson Consultants to propose thermal improvements to the walls and roofs, adaptations to the windows, and a light cooling hybrid radiator system for mechanical cooling.

These windows by the architect show the adaptations to the windows. A new triple-glazed, high-performance aluminium window system was proposed to retain the narrow appearance of the window profiles while also improving the windows' thermal performance in summer and winter. New external shutters were designed to reduce solar radiation, operated electrically from inside to give occupants control. Following the installation, the design team set up thermometers to monitor rooms with and without shutters on the same side of the building. During this test period, the mechanical cooling system was kept turned off.

This graph shows data from 21st of June 2025, when there was a peak external temperature of 37 degrees. K38, the control room, had the shutters left open. K23 and K39 had closed shutters. And you can see that the temperature in these rooms was more consistent, and two to four degrees lower than the control room. To reduce operational energy during normal use, the mechanical cooling system will only work in each room if the shutters are already closed.

This prioritises passively reducing the solar gains before relying on mechanical cooling. Our third case study was backstage at the Old Vic. The Old Vic Theater is a Grade Two Star listed building situated in Lambeth, London. It is one of London's oldest theaters, opened in 1818, then known as the Royal Coburg Theater. The theater's Waterloo Road Elevation comprises of highly significant pre-Victorian flank walls and a smaller post-war facade which forms the front of a separate unlisted structure, 131 Waterloo Road, a former public house that suffered extensive bomb damage during the Second World War, and was replaced.

The Backstage building creates a new hospitality and community offering for the theater before and after shows. It forms an important connection to the newly refurbished back-of-house areas to improve accessibility for all users. The building's new timber frame structure has low embodied carbon and makes use of several passive architectural measures to minimise energy use and reduce the risk of overheating. A bespoke brise-soleil made of repurposed theater barn door lights provides solar shading to the glazed southwest-facing facade, whilst creating a decorative feature to bring colour and playfulness to the street face of the building. A projecting balcony provides shading and weather protection to the ground floor and entrance.

Natural ventilation was not possible from the front street facade to the south due to high air pollution levels. The brief specifically excluded mechanical cooling, requiring the services engineer Skelly and Couch to devise a fully passive ventilation strategy. Fresh air is directed down through the stairway core, bringing cooled air into the ground floor, which then rises up out of the building via a central solar chimney through the internal spaces to roof level. The strategy to reduce the risk of overheating included the use of solar shading, high-performance glazing, increased ventilation rates, and nighttime purge ventilation through automated damper controls. The assessment by Skelly and Couch showed that the large areas of unopenable glazing to the south facade would require a minimum of 33% to 45% shading provided by the brise-soleil to avoid overheating.

The old Vic put out a call for disused barn door lights from theaters across the country, which were cataloged so that architects Hayworth Tompkins could explore, model, and test possible shading arrangements to repurpose the barn doors as a suitable brise-soleil. The resulting feature is both functional and unique, demonstrating a creative solution that enhances the street presence of the historic building and its connection to its cultural context while reducing the risk of overheating. The measures we have suggested may all successfully contribute to reducing the risk of overheating in historic buildings. A combination of external shading and natural ventilation can provide the most effective reduction of overheating risk. Simple interventions which reduce overheating without complicated requirements for occupant engagement should be prioritised.

A holistic approach considering context and seasonal responsiveness is therefore recommended to gain the benefits of these measures. We found there is a wealth of published international data modeling which proves, in theory, the effectiveness of many of the passive architectural measures described. But there is a distinct lack of well-evidenced case studies which demonstrate the successful use of these measures in practice in England. This highlights the need for more publicly accessible documentation of real world projects by heritage and built environment professionals and organisations, many of you here today. Wider use of international internal temperature recording from the early stages of a project through to occupation will help to demonstrate and learn from the use of passive architectural measures to help building owners make more informed decisions to improve the resilience of their buildings.

Thank you very much. Do let us know if you have any questions in the chat. Fantastic. Thank you very much. You've conduced a very, very long, long research project into hopefully, from what's going on in the chat, a very well considered background story.

I think one of the things that was slightly harder was when we had the risk matrix up. I think yeah, when people see the report, I think there'll be a better understanding of that. It was quite - which hopefully is next out next month - so the risk matrix, just to give everyone a bit of background, it basically looked at every single technical aspect or problem you might have and it kind of supported you in making that decision of, you know, if we were going to do external shading, what is the impact on the structure or the fire strategy and stuff like that. It provided you with that technical area of what the areas that you needed to consider were. I feel like I'm jumbling a bit and I was really impressed with your guys' wordings.

You were just coming out with these Spanish phrases and I was going, was so glad it's not me saying it, that's what I was thinking today. So we've got a couple of questions in the chat, so I'm just gonna read those out. What extra difference did the triple glazing make over double glazing on Queens College? And also do we know was the cost and embodied carbon justified? We'd need to speak to the architects for that project on that one I'm afraid Jo.

Yeah, The monitoring and that graph that we showed was specifically to do with the shutters, so we can't comment right now on that, Yeah, I think that was something we found quite tricky when we were looking for case studies, was we almost wanted case studies that had only installed one change so that we could justify which change is going to be the most effective with the lowest investment. That's something that would be really interesting to understand, but actually when you're looking at real world projects, people are applying multiple things at the same time because that's how construction works and retrofit works. Yeah. And it is, it was the struggle of trying to get case studies. We've had loads of people in the chat being like, yeah, more case studies.

And I'm like, yeah, we're trying people. If you have a case study, please let us know because we're always looking for them, not just in overheating. So someone asked: Would be good to see, oh yeah, this is slightly more of an us one, so would be good to see if there has been any research on the use of solar panels to reduce solar gain on roofs. I know you guys did a bit on solar panels as blinds- Brise soleils solar panels is quite common. Yeah.

Yeah. And it, we found, there was a study that showed you could potentially use solar panels as awnings because the angle that's ideal for a solar panel is almost the same as the ideal angle for solar shading. So that was quite an interesting one but there wasn't a lot more written on that that we could share a lot of examples of. Yeah, in my head I'm going fire risk. Yeah.

So that's really interesting. And wider, outside of the work we are doing, actually the technical conservation team is currently looking at the issue of potential condensation from solar panels on roofs. Mm-hmm. Especially metal roofs. Yeah.

So that's quite interesting. That's done from another team. Were there any simulation studies done to predict the potential energy savings in some of the buildings? I know with the Old Vic project there were a lot of modeling studies done by the services engineers. I don't know whether it was specifically about energy savings, because we were asking them specifically about overheating.

But we, we can also find out and we, if anyone wants to know, we could also email later. I think the Erasmus building was modeled and that was done. There was a lot of science backing up those decisions and then that those graphs that we've shared were post completion monitoring. Yeah, no, it's interesting 'cause you guys did, for the butter market, you did modeling for that though, didn't you? To see what the improvements are even though that wasn't overheating.

Yeah. You looked, did it from your embodied saving. Yeah. Looking at embodied carbon and operational carbon and trying to work out the balance. because I think it really is on a case by case basis.

There's not a blanket answer for that at the moment. Yeah, no, that is the problem, isn't it? And if anyone's trying to do carbon calculations at the moment, it's always a tricky one is what I like to think. So did you include any consideration of human behavior and the gap that needs to be bridged between building users, occupants, et cetera, against interventions? We didn't specifically, but we know that that's actually something quite important that needs to be done.

I think we, We raised, because obviously there are interventions which just work like a fixed shading device, but there are interventions which need people to intervene with them. Yes. So that was raised as a risk that if you are expecting someone to do an action to make something work, there has to be someone who, if it's a public building that is their job. Otherwise these things don't get changed. It was quite interesting in our discussions with the design team of the Old Vic and the backstage building, they found that it's almost about a mindset for natural ventilation because occupants are used to a very certain type of building setup.

So people are used to air conditioning and they're used to a certain feeling of a building. And with natural ventilation you do have the potential for drafts or the sensation of drafts. And then also there's an operability in how it gets used and adjusting for that building if you're used to an automated air conditioning system. So it's almost, I think it's needed that before these measures are introduced, you need to teach the people who are going to be using them, what it's gonna be like, and maybe to be able to visit other buildings that have done it helps people to experience what that building is going to feel like. Yeah, it was a key one in the risk matrix, wasn't it?

We were discussing thermal comfort and how it's perceived and we were really lucky on the project actually. We had quite a big team actually of different professions working on it. We also had someone from the department of energy security net zero and they said, didn't they, that their office is completely controlled by mechanical ventilation system and this is really unbearable because you can't do anything. And it is that, it is that question of when we think about these measures, what is it we can control? Mm-hmm.

Which is why the focus was on passive measures, wasn't it? We didn't, we recognise that mechanical and electrical has a place. There's, we're not, none of us are saying on this call that it's not got a place. But what we're saying is actually what are the low energy solutions you could do? Yeah.

And it's that question and I think a lot of the questions in here have been like, but what about significance? And we really grappled a bit, didn't we? Because we said you can't discuss significance without a case study. Yeah. And it was hard, wasn't it?

It was kind of like, you want to go but this is really impactful and we're going, yes, but you can't use the building and we don't know what the building looks like. So I don't know how you, how did you guys find that as, you know, your day, your day and day is sitting on a conservation site and going, what is the significance, what's important? How did you find that when you kind of approached the subject? It was quite challenging for us because every single measure that we came across, we were thinking, oh, but what would that do to the building? And so it has been in the back of our minds constantly because it is what we do, significance heritage, it's a key consideration for all of these measures.

But the brief of this report was to work to illustrate the measures that could be used. And that's why the risk matrix kind of sets up all the various considerations that need to be applied. And some of those would fall quite neatly into your significance because they are the same questions that you would be asking when determining whether it would have an impact on the building. Yeah, no it does, doesn't it? Because we're, for those who might have seen Claire, who is Vanessa and Jen's boss, she did one of these about nine months ago with me on Tone Works, which is an amazing site that we were all together on last week, weren't we?

And one of their biggest issues is overheating because it's how much glazing is in that building and it's those considerations you have to go, but it was intentionally built that way. And you know, they used it for the natural lighting and you go, but can - is it a use thing? Do we change the use? Do we change the building? And it's all of those questions you have to raise, don't you, in the heritage sector.

We have to really think about it moving forward. Yeah. I'm very aware Poppy's going to have my hand if I don't say that we're coming to an end. because she's got a few things that she's got to raise. I'm really sorry to everyone that we didn't get all the questions answered.

We will have a look at those and try and come back to you as and when we can. Otherwise I just want to say thank you Vanessa and Jen. Thank you for everyone who attended and over to you Poppy.