Technical Investigation. Retrofitting solid Wall Dwellings

Technical Investigation Ryan John Cooksey

DENT How VERSION is it possible to resolve the

ESK STUDENT VERSION

specific challenge of energy efficiency of a traditionally constructed brick building using internal insulation techniques?

Should the focus be on how to resolve issues with an existing building that has already paid back its carbon balance over its lifetime, by investing in improved detailing at problematic junctions and thermal bridges?

Ryan John Cooksey Birmingham City University S17123027 ARC6012 , Level 6 Technical Investigation 16 December 2019

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Contents 1. Individual assignment:

- 1.1 Introduction........................................ 3 - 1.2 Case Study.........................................4 - 1.3 Inproving Thermal Performance and Maintenance.......................................5 - 1.4 Discussion...........................................10 - 1.5 Conclusion..........................................13

Appendix 2. CAD Drawings:

- 2.1 Adapted Group CAD Drawings.............15 - 2.2 Indervidual CAD Drawings....................17

3. Group Task Appendix:...................................................19 4. Site Visit:

- 4.1 Lime Manufacturer......................................23 - 4.2 College Road.............................................24

6. Bibliography and References........................................ 25

The following article is an investigation as a result of a group exercise narrated in the appendix.

In this case the investigation was to retrofit the problematic junction of a window. Prior to the task, in order to understand the importance of breathability as a group we visited a lime manufacturer and college road this was to then inform the group model.

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How is it possible to resolve the specific challenge of energy efficiency of a traditionally constructed brick building using internal insulation techniques? Should the focus be on how to resolve issues with an existing building that has already paid back its carbon balance over its lifetime, by investing in improved detailing at problematic junctions and thermal bridges?

Outside elevation of the group task; solid brick wall using the Flemish brick bond, laid on lime mortar. PVC window frame sits above A traditional stone cill. Bridged with a flat steel lintel and Headers.

Figure 1:

Section 1.1: Introduction: This article focuses on the question, should older buildings (Pre 1919) be retrofitted? In the introduction I will be discussing the need for insulating older buildings and why the need for retrofitting has become topical. In the next section I will look at a case study to understand the use of a traditional form in a highly efficient new housing scheme. This leads on to a discussion on improving thermal performance as well as the effects of craftsmanship. I End in a conclusion on the topic discussed, while challenging regulations between conservation and UN targets, on how to resolve issues caused by retrofitting. What is the best course of action for a building that I would argue has already paid back its carbon balance over its lifetime? Typical new construction in the UK releases around 45tonnes of CO2e, At the current regulations standards it would take “34 years before the savings in operational carbon have matched the extra embodied carbon that has been spent to rebuild the house” (Jones, 2015).

So, should investing in improved detailing at problematic junctions and thermal bridges be the solution? To find a cost / thermal balance rather than focusing on uneconomical and unsightly construction methods. Maybe we should focus on prolonging the life of new buildings as dwellings are only built to meet a life expectancy of 60 years. (Hunt and Boyd, 2017).

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This particular topic has become key to all stakeholders and finding concise research is challenging.

“26 million dwellings” are currently standing across the UK, “80%” of which will still be habited in 2050 (Pelsmakers, 2015, p. 277), 85% according to Geof Lister (federation of Materbuilsders) (Killip, G. 2008, p.4). So action must be taken to achieve climate goals. 7.6million dwellings in the UK have been constructed with a solid masonry wall, resulting in the absence of a cavity, so internal/ external retrofitting is required.

Yet of these, an abysmal 1% (Pelsmakers, 2015, p. 277) have been retrofitted. What is the reason for a lack of internal wall retrofitting in solid wall dwellings? Demand for further upgrading thermal qualities has continually been the attention of homeowners in poorly or uninsulated dwellings to reduce economic loss.

However, with the current climate situation, elaborated by the UN climate crisis as well as the UK Government announcing a climate change emergency in May 2019. (BBC News, 2019) Collectively the climate crisis has forced plans for a carbon-neutral society by 2030. Thermal qualities of homes have become ever more significant, with sustainability being at the forefront of briefs.

As a result, forcing governments and professional bodies such as Historic England and RIBA to challenge and confront the planning of new commissions.

For future commissions reducing embodied carbon throughout the ‘whole life’ is part of the design process. That aside, the challenge lies with older buildings within the UK to respond/adapt to the new regulations.

Prior to the introduction of cavity walls in 1920’s, dwellings were built with 1 skin of material making them a solid wall. Solid wall buildings must act accordingly to reduce thermal waste. Even the most current buildings and developments are not being designed to meet the targets of 2050, “80% of new homes are estimated to be outdated by 2050” (UKGBC 2019). Meaning even the newest homes need to be retrofitted to meet the 2050 targets. Throughout this article, there should be an understanding of economic, environmental and political studies around the topic.

How is it expected that older buildings, even those listed at grade 1 meet 2050 targets, when a new construction with modern technology cannot?

Global Greenhouse gas emissions by sector 2016.

The UN claim that 8% of green house gasses can be Irradiated if all building met Lifetime carbon zero standards.

Figure 2: Adapted by author

Section 1.2. Case Study - Goldsmith Street, Norwich A street photograph of College Precincts, Worcster

A street photograph of Goldsmith Street, Norwich

Figure 3:

Traditional dwellings, especially those using a solid brick wall construction, have become a precedent for modern construction. Terrace housing has some fantastic energy efficiency properties, all be it with dated materials and poor junction techniques. By adopting a party wall layout, Goldsmith Street, Norwich by Mikhail Riches with Cathy Hawley, was awarded the Stirling Prize (fig.3). Constructing a party wall either side of the property reduces external wall

coverage. In terms of reducing embodied energy, this layout of dwellings is efficient all the way through to end of life, by reducing material, and lowering in-use carbon. Built to Passivhaus standards, one would recognise this as triumphant. However, this should not be an example to pre1919 dwellings as implementing modern materials in new dwelling’s eliminates problematic junctions due to then being rectified in the technical planning stages; the same materials in older

Figure 4:

dwellings cannot be adopted without damaging character, or without being problematic. It is here where one should agree with William Mann’s reasoning “like to think that tradesmen who originally built Astley Castle would recognise the value of the new materials we’ve used and at the same time said I wish I had that” (Hunt and Boyd, 2017, p. 75) .

In the same way that those who built pre 1919 dwellings would appreciate the need for cavity insulation today.

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I have recognised other methods of retrofitting, however these will not be discussed in this article

What are the other methods of increasing energy efficiency?

-Draught proofing.

-New windows, double or triple -glazed.

-Secondary glazing -Sealed and taped services (internal to external) -Insulating reveals -Internal insulation.

-External insulation.

-Insulate roof.

-Insulate Loft -Insulate floor.

-no reasonably avoidable gaps.

-Understanding that the moisture in masonry affects the performance of the insulation.

-The worker must be mindful that the building is potentially listed and MUST Reinstall historical features on top of the insulation to maintain the dwellings heritage.

Section 1.3: Inproving Thermal Performance and Maintenance As explored in the introduction, building regulations are continually being updated to meet new energy efficiency targets. Listed buildings are some of the most inefficient dwellings in the housing stock market, but conversely listed buildings are exempt from these regulations. This is justified in part L of the building regulations, as altering the appearance of dwellings by adding new materials could have irreversible effects, altering the characteristics of the building. Also, at some crucial junctions, incompatibility of new materials interacting with the existing may become problematic and collectively have an effect on the expected performance of post retrofitting.

Figure 5:

Highlighing possible retrofitting techniques for a solid wall pre-1919 dwelling

Insulate rafters Insulate loft (joists) Internal wall insulation Insulate reveals Draught Proofing

New windows, double or triple glazing or secondary glazing Seal and tape services (external to internal) External wall insulation Update door Draught Proofing

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Insulate joists (if the floor is not concrete, otherwise excavate down and insulate) Sealed and tape services (external to internal) Figure 6:

Primarily before commissioning major works, other methods of reducing thermal loss must be assessed.

Briefly, airtightness achieved by sealing around openings is a process that doesn’t interfere with the aesthetics.

When comparing internal wall insulation, costing up to £360 per m2 (Pelsmakers, 2015, p. 293)(Fig 7). Justified if the dwelling requires a refurb and is empty as there is a need for adaptation of plumbing (radiators) and electrics.

The adaptation consumes some floor space, is there room for it? Assessing the justification for a rip out is necessary from an environmental point of view. Recognising unnecessary removal of components that haven’t fulfilled their full lifespan, means that the embodied energy within them hasn’t been fully exploited.

Identifying Pros / cons of Internal/External insulation: Internal Insulation

External Insulation

Good Practice: Insulation fully covers the reveals and the cill.

Without breaking the insulation line.

Poor Practice Insulation does not fully covers the reveals and the cill. Without breaking the insulation line.

Cost per m2

£120-£360

£150-£160

Can damage aesthetic of the dwelling possibly irreversible effects

Can damage aesthetic of the dwelling however the internal materials Can be replaced. irreversible effects

Mess effects homeowners habitable spaces (dust)

Damages aesthetics

Figure 7: 6

EV TNEDUTS KSEDOTUA NA YB DECURetrofitting DORP

Solid Walls:

Importance of breathability:

Fig.9 Open/Closed Moisture transfer examples: Key: Moisture Transfer Moisture not aloud to breath leading to damp Vapour closed Insulation (permeable) Vapour open Insulation (permeable)

NOISREV TNEDUTS KSEDOTUA NA YB DECUDORP

Firstly, the term breathability internally and externally (fig 9). needs to be understood and With this in mind, when retrofitting not assumed that breathable a solid wall, specific ‘breathable’ construction details compromise materials need to be used (fig airtightness. Materials used in 8). (Public roads vol 24) states Lime traditional building methods has a higher moisture mass (Pre 1919) were consistently compared to cement ; public permeable throughout each roads is an example that it is vital EV TNEjunction DUTS KSand EDOTwall UA NAfabric.

YB DECU ORP all other materials used toDensure Collectively non-permeable must correspond to this attribute, barriers prevent moisture from since upgrading may become being absorbed and transferred damaging and costly if not carried in a linear form, both internally out correctly. and externally. A ‘breathing’ structure allows the moisture to be freely exchanged between materials and environment both

This table categorises some permeable and non-permeable materials to gain an understanding of those that are suitable for ‘breathability’.

Permeable

Non-Permeable

-Non Permable --Lime Mortar -Natural insulationmaterial -Damp course -House bricks (DPC) -Lime plaster -Non-permeable membranes (DPM) -Introduction of cement -Wall cavities -Foiled insulation -Non permeable cladding -Cement mortar Figure 8:

Solid Wall (Flemish bond pre 1919, Lime mortar), transferring moisture as materials are breathable.

Solid Wall (Flemish bond pre 1919, Lime mortar) Poor retrofitting, vapour closed insulation used on a breathable wall. This will lead to internal damp as moisture cannot be PRODUCED BY AN AUTODESK STUDENT VERSION transferred.

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Good retrofitting, allowing the wall to dry out . With the correct use of vapour open internal insulation.

Figure 9:

have been insulated” (Pelsmakers, with internal/external insulation in the UK. Forcing an ambitious task as 2000 dwellings would need to be retrofitted each day until 2050 to achieve a “zero or low carbon stock by 2050.”

(Pelsmakers, 2015, p. 277). Altering the thermal performance when retrofitting has the possibility of Consequences of condensation leading adjusting condensation levels, to damp these may become a risk. Surface condensation on materials that make up the facades or between NOISREV TNEDUTmaterials, S KSEDOis TUknown A NA Yas BD ECUDORP ‘interstitial After understanding the importance of breathability this next section focuses on the effects of ignorance towards it.

Retrofitting solid wall dwellings can be problematic, one not pursued by many, this is evident as it has been reported only “1% of solid-walled dwellings

Figure 10:

2015, p. 277)

condensation’.

Retrofitting vapour barrier materials within a pre-1919 solid wall construction won’t allow the building to perform correctly. The use of Incompatible materials in time would; increase health issues, inevitable future maintenance resulting in fabrics appearing damaged/unsightly. Mould is most common in these conditions; warm Damp surroundings, (fig

Insulation anchors: Ensure that the insulation anchors do not transfer heat; a product with low conductivity is required.

When applying insulation, the correct fixings must be used to meet standards within the Approved Document, Part L. The detailing of the fixing is crucial as there can’t be cills within the design of the fixings that could cradle condensation.

Moisture within breathable materials is inevitable, so fixings

need to be rust-resistant to provide a prolonged product life. aslo,Consideration for moisture travel should be incorporated in to their design. Countersinking the head of the screw into the insulation should be considered to minimise thermal bridging; this countersunk hole must be plugged with insulation to avoid cold spots due to decreasing insulation thickness.

10). A building must be able to breathe if the properties of the materials used are permeable, if this is not the case passive and mechanical extraction of internal condensation must be taken into account - Respiration, showers, hot drinks, and cooking all increase the humidity leading to condensation. Externally water naturally infiltrates in via saturation of the external façade, increased by wind-driven rain, as well as vertically through the damp within the ground are factors. Salts within lime are ‘hygroscopic’ which means they have an “affinity for water and exacerbate the problems of damp” (Historic England , 2016). A result of attracting moisture which then leads to the conditions for mould growth.

However, the movement of water vapour can improve air quality by regulating vapour.

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Effects of Ignorance to breavability

3D Model of a insulation anchor junction

Figure 11:

An insulation anchor junction

Figure 12:

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In order to understand problems when retrofitting, insulating a window junction drove a group investigation task. Collectively constructing a solid brick wall using the Flemish bond pattern, selecting material’s and style to interpret a traditional pre1919 dwelling. We discovered installation of insulation around window, junctions become problematic. A few factors affect the performance of retrofitting, these are; does the width of the window frame allow for a consistent thickness of insulation to be used when insulating the reveals. If not, then consider a

replacement window for one that is compatible; however, damage to the external facade may occur — One must recognise the loss of heritage value of windows and the economic cost against the payback.

On the other hand, the use of thinner insulation could be used, allowing for a sufficient amount of frame left for the plaster and final finish of the internal wall. Thinner insulation is better than no insulation; however, using ‘lighter’ materials, substantially reduces the thermal benefits. Where two thickness of insulation meet, cold

spots are present. Insulation must be used around all four jambs of the window to ensure that there isn’t a thermal bridge*. Insulating correctly around windows is a crucial part of retrofitting as it is estimated that up to “25% of internal heat loss is through thermal bridging” (Pelsmakers, 2015, p. 247). Consider using higherperforming insulation in these areas to minimise the potential of thermal bridging. *Bridging are unaccounted at cills, and window heads.*

When is the right time to retrofit, to reduce the economic and environmental impact: Carbon reduction needs to be carried out within the housing stock to meet the zero carbon targets while doing so at the appropriate time. Dwellings must be assessed individually on the disruption caused to the homeowner; alternative accommodation may need to be an option, due to health risks when carrying out major renovation works.

Window junction thermal image:.

Retrofitted Dwelling built Pre-1919: Internal Photo

Internal thermal imaging Photo

Figure 14:

Dwelling built in 2019: Internal Photo

Internal thermal imaging Photo

These figures evidence that there is greater thermal loss in the reveals of retrofitted pre 1919 buildings than newly constructed dwellings. This possibly can relate to no or thinner insulation used in the reveals of a retrofitted dwelling.

Greatest amount of thermal loss

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Least amount of thermal loss Figure 13:

Section 1.4: Ways that the quality of the work affects thermal performance of retrofitted insulation.

This next section focuses on problems regarding human factor when retrofitting. Firstly, one must aknollage that one techcnical detail and assesment need not suit all. This stage can cause significant complexities when carrying out a survey, such as; irregular patterns, poor quality craftsmanship and incorrect materials. Bristol City’s Guide to Solid wall insulation, (Bristol City Council, n.d.) recognises that there is a plan that should be followed before retro fitting; assess, design, install and use. Each junction needs to be considered with an individual assessment when considering the vast amount of complications that can result from a variaty material choice and quallity of craftsmanship. The visual appearance of a junction can be misleading. One would expect a consistent use of materials and quality of craftsmanship, but this isn’t always the case. The contractor has the most amount of power resulting in the success or failure of a detail; although the designer and researcher can accommodate for variables, it is the worker that has to be relied on to implement the plans successfully. The designer needs to ensure a realistic detail with clear, bespoke information.

The craftsmen need to acknowledge the importance of correct instalment according to Hunt, “procurement is very important to the process” (Hunt and Boyd, 2017, p. 36), to achieve the highest quality output. Craftsmen opting for shortcuts affect the performance of a building. These shortcuts would include the use of broken bricks. For example, headers within a Flemish bond may be half bricks to consume less material in construction, leading to lower costs. (Dollard, 2018) (Hunt & Boyd, 2017). Affecting the thermal ability of the building.

Team effort/individual efforts are essential for sucessful retrofitting.

Quality assurance at junctions is fundamental when justifying the benefits against cost. Upon cutting the insulation, an impeccable joint should be pivotable to ensure the highest performing thermal barrier. A thermal bypass is caused if this is not the case due to internal air being in contact with the solid wall. Pelsmakers estimated that “heat loss through walls is 50 – 350% less in reality than designed” (Pelsmakers, 2015, p. 247). Good practice after retrofitting insulation would be the application of a bead of silicone.

The silicon should be to BS standards; it should be flexible to accommodate for the historic buildings natural subsidence, be allined along with the meeting point between insulation and window frame to prevent fracturing the airtightness barrier.

Inconsistencies in the airtightness of a window can cause up to “15% heat loss” (Pelsmakers, 2015, p. 250) In terms of human error, the rectification of these issues is achieved by composing an upgrade policy/plan for many junctions such as the Builders book. However, when seeking advice, publications are delivered in terms that not all can understand, they can also be extremely broad when assessing faults.

When considering tradespeople, increasing responsibility to improve quality assurance is something that many suggest including Historic England and Ian Boyd. To minimise additional issues at already problematic junctions, the assurance of installing products that meet part L and SAP specification by tradespeople where suitable training and experience is favoured.

Section- Insulating a problematic window junction

Figure 16:

Gaps in the insulation at corner joints

Figure 17:

Slight gaps in tongue and groove system

Figure 18:

Problematic junction, there isn’t a corner Insulation system

Figure 19:

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My discussion on embodied energy (various definitions) payback

Payback time for any retrofitting should be the forefront of discussion and in this section i recognise the value of older buildings and their embodied energy benefits over new construction. The question is; is it worth retrofitting for economic and environmental benefit? When considering that the current expected lifetime of modern buildings is “60 years” (Hunt and Boyd, 2017, p. 54) and that the pre-1919 buildings are a century old at least, it is worth assessing the longevity. Here an argument is raised, first impressions of a ‘High Tech’, ‘sustainable’, ‘home for the future’ all seem favourable however it is time and use that allows success and durability to be measured.

Assessing the value of retrofitting with an economic eye

Uninsulated Elemant

Estimated U-value W/m2K

Upgraded Frabric elemaent W/m2K

Estimated Upgrade Costs

U-value Benerfit in order (1 Lowest-6 Highest)

Cost in order (1 Lowest-6 Highest)

solid brick wall

1.42-2.52

Internal insulation 0.14-0.21 external insulation 0.10.15 0.07-0.16

£120-£360/ m2

5

4

£150-£160/ m2

6

2

£14-£80/m2

4

1

£260/m2

2

3

Unisulated roof Single glazzed window

2.3 3-5.4

Double Glazzed: 1.1-2

Figure 20:

Steps to consider before retrofitting -The heritage values (significance) of the building -The construction and condition of the building fabric and building services -The existing hygrothermal behaviour of the building -The likely effectiveness and value for money of measures to improve energy performance.

-The impact of the measures on significance -The technical risk associated with the measures With all the relevant retrofitting carbon reductions can be reduced by 40%, in turn reducing operational energy by 80%. (Pelsmakers, 2015, p. 277) 11

Figure 21:

Should calculations be the cornerstone of choice when considering the option of retrofitting? Determining thermal performance in a laboratory; an environment controlled, differing from the material in use. Solar gain, wind penetration and driving rain as well as fluctuating temperatures through the year, generate a performance gap.

Which suggests ‘are solid walls as bad as they are labelled.

BRE has carried out a detailed study, ‘The nature of solid walls in situ’, indercating solid walls typically perform better than expected. This study is reliable as the fieldwork was collected by respected researchers (Hulme,J).

They conclude by suggesting the u-value should be lowered

for solid walls to1.75W/m2. This contradicts Pelsmakers figures that are as high as 2.52W/ m2K (fig.20). BRE concluded the lowering of this figure is due to: cavities being formed by poor craftmanship, in some cases snapped bricks were used to form part of the inner leaf. Excessive research, covering 137 dwellings, into the moisture content within the bricks concluded 0.8% much lower than the 5% assumed.

Although solid walls perform better on average, anomalies are present. Concluding individual assessment should be carried out for each dwelling.

What was the reasons for the Green Deal scheme failling?

Since their launch in 2013, ECO and the Green Deal have delivered significantly fewer measures then previous schemes.

- The Green Deal Interest rate was too high -The Green Deal didn’t help those in real energy poverty -Fixing the finance to the house instead of a person -The Green and orange ticks on the Green Deal Report.

-The Set up costs charged by Providers was simply too high!

The Retrofit 2050 group have estimated that in “2080 for each refurbished Victorian house, an equivalent five houses can be heated if they have been upgraded to carbon zero standard” (Pelsmakers, 2015, p. 288).

Longevity decides whether refurb or demolish is the best action.

(Fig 24) Calculations on embodied energy favour the removal or retrofitting older buildings. New dwellings have a payback of 34 years.

An influential figure in the conservation field, John Ruskin, wrote “our duty is to preserve what the past had to say for itself, and to say for ourselves in the future” (Hunt & Boyd, 2017, p. v) Part L section 3.6 a of the approved documents states that listed buildings are exempt from building regulations, to prevent possibilities of irreversible loss

Maths behind retrofitting a victorian house: Victorian dwellings were constructed between 1837-1901. That would give them a lifetime between 2-3 times more than the expected (60 year) lifetime of new construction . Not the five times needed to justify them not retrofitting.

2019 - 1837 = 182 how many liftimes of a typical new house is that = 3 so the victorian dwelling needs to be habitable for another 118 years to justify not being retrofitted.

Figure 24 by author:

Figure 22:

of characteristics. However, one must consider the whole life cycle of a building. ‘Cradle to Grave’ explained by Michael Braungart and William Mcdonough in their publication Cradle to Cradle, orientated by doing more with less. The older dwellings have been slaves to owners for decades, built for adaptivity, built from the highest quality materials of its time, resulting in the durability and longevity of them.

Hunt and Boyd have recognised the sustainable value within older dwellings being in favour of older buildings due to older buildings “proving their adaptability and durability” this is supported by their statement that “old buildings are intrinsically sustainable due to the natural materials used to build them” (Hunt & Boyd, 2017, p. 29). Can a modern structure be as environmentally aware?

Older buildings, as recognised, were commonly constructed using natural materials, sustainable materials such as timber. Arguably timber is still a sustainable material. However, the same piece of material may hold extremally varied embodied energy. The locked energy in the past timber products would be deficient locally sourced materials. Today’s value holds a much higher locked embodied energy due to, engine-powered transportation, tools and equipment used, joinery methods would now include adhesives.

Final coatings such as paints are much more fashionable In an older dwellings proving longevity, carbon expenditure can be justified. Although in modern

construction with short life spans, would the additional embodied retrofitted energy be repaid? Via greater amounts of reduction in operational embodied energy.

Agreeing with Roger hunt that assessment should be between quick wins and complete retrofitting solutions to maximise environmental gain.

Application of internal wall insulation is hugely disruptive, responsibility when retrofitting is needed. Is heat loss through lack of insulation greater than thermal mass gain in the summer?

Within the assessment of (De) construction, all the above characteristics should be discussed. When improving the thermal performance of a building, this would introduce new materials and components, therefore, increasing the embodied carbon.

Sofie Pelsmakers recognises that lowering energy demand within a well-insulated building should be a “priority over a reduction in carbon” (Pelsmakers, 2015, p. 199).

Sponsoring it by suggesting that the improved insulation will “reduce carbon emissions now until the end of the buildings lifespan” (Pelsmakers, 2015, p. 199) I agree with this statement if the overall the saving of operational energy is greater than the embodied energy consumed when retrotfitting. An economic and environmental assessment must be made for the least damaging solution. With evidence entirely in support that there is longevity within the commission.

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Section 1.5, Conclusion: This report has outlined issues associated with retro-fitting, and highlights that the focus should be shifted to co-operation from all stakeholders to ensure the action taken is within the best interests of both; “what the past had to say for itself” and the current global warming crisis. Essentially what is the added value of retrofitting? Assessments must be undertaken for individual dwellings with the question of, Is it worth demolishing dwellings in order to reconstruct them to current standards spending more energy for that dwelling to only last 60 years when the dwelling beforehand could have been fine? Or is this more damaging when whole life embodied energy is concerned? Does the payback time exceed the lifetime of the dwelling? In my opinion, demolishing a dwelling should be the last step considered even so ‘cradle to grave’ analysis should have been taken place. To ensure the least amount of environmental damage through demolition emissions and end of life carbon use. As well as social effects in the local area by losing a potential character in local heritage. Calculating Whole life embodied carbon, and economical costing is necessary. However “Less harmful is no good” (Mcdonough,W and Braungart,M 2009), it is difficult to suggest the most appropriate action when figures are based on Longevity. The construction industry is “accounting for 45% of CO2 emissions in the UK” (Baker-Brown, 2019, p. 15) Currently construction is not meeting the circular economy aim, as it is still very much a linear process. This is because as the construction industry is the “largest source of waste generated in Europe”. So, keeping the remaining structure and investing in appropriate retrofitting, overseen by a ‘retrofitting champion’ seems the best course of action. In order to access and resolve issues when retrofitting the current housing stock.

Next Steps....

Key things to take from this article: -Collaboration from all stakeholders is key.

-Individual assessment must be carried out.

-Does the payback time and cost both economically and environmentally favour retrofitting or 0demolishing?

-Education and responsibility must be at the forefront of workmen’s actions -Issues related to poor retrofitting -Understanding that retrofitting must be carried out at the correct time.

Figure 23:

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Appendix This Group project will investigate these issues through building full-size mock ups to test solid wall insulation products and detailing of fixings, especially at junctions, to prevent thermal bridging. We will use information published in McKay (1938) to understand traditional construction methods.

“There are over 6 million pre-1919 dwellings in England with solid, load bearing walls. This traditional building pathology is different from cavity wall construction, in that they have to ‘breathe’. They are designed to let moisture in and out of the structure through porous and permeable materials such as lime mortars, renders and plasters.” (Jones.M, 2019) The following pages are th results of a group investigation narrated in the form of an appendix. In this case the investigation was to retrofit the problematic junction of a window. Prior to the task, in order to understand the importance of breathability as a group we visited a lime manufacturer and college road this was to then inform the group model.

Members of the group task: Ryan Cooksey Sufyan Mufaffar Raheem Gillingan Liam Ram

*All work, Technical Drawings, Tables, Photographs and images are Produced by Author and members of the group task stated above, then adtapted by author*

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Section 2.1 Cad Drawings: The following CAD drawings are based on the materials and dimensions used when constructing the group task. 215mm solid brick wall. Laid in the form of Flemish bond pattern. Use of engineering red bricks then later retrofitted with internal insulation.

Key: 1- Window Stone Window Cill angled Cill angled away from away the wall/window from the wall/window with a generous with a generous drip on the drip on the underside. underside.

4- Insulation potentially overlaps the sash of the window.

Future removal of the glass is made difficult

2-- PVC PVC Window Window frame frame

5- 52 mm wood fibre insulation.

of sandBY and 10- A mortar mixPRODUCED AN AUTODESK STUDENT VERSI lime (ratio 3:1) with sufficient water to ensure the mortar is workable.

6- 120mm Insulation anchors

11- 25mm flat steel lintel

A

A

A

A

a

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3- A A continuous continuous bead bead of of silicone silicone around around the window the window frame that frame bonds thatto bonds the brick to the opening brick opening (colour (colour to match to match Window Window frame)frame)

a

09- Internal wooden window cill a

a

7- Finished plasterboard a

8- solid brick wall

Section a

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Rear Elevation (C)

1:20 Side Elevation (B)

Side Elevation (B)

Plan (NTS)

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Plans Prior to insulating

Section b

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46mm Queen Closure (As defined in McKay)

46mm Queen Closure

Front Elevation (A)

(As defined in McKay)

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215mm Queen Closure (As defined in McKay)

10mm Mortar Joint

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102.5mm header

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215mm Stretcher

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1:20 Rear Elevation (C)

1:20 Front Elevation (A)

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1:10 Plans after insulating 1:10 Section b With Insulation

NOISREV TNEDUTS KSEDOTUA NA YB DECUDORP 5

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2

1

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3

1:10 Section (a) With Insulation

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ED BY AN AUTODESK STUDENT VERSION

1:10 Section (a) Without Insulation DESK STUDENT VERSION

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Section 2.2: Indervidual Cad Drawings: Based on 1:1 group model Consistent insulation anchors.

Effects that retrofitting have on windows

External Maintenance and details

Issues with tongue and groove insulation system

TITLE

Block Colour Exploded Visual

PVC Window and a bead of silicon Steel Lintel

Insulation Anchors Insulation Stone cill 17

Flemish Bond, Solid Brick wall

Retrofitting being problematic at window frames (NTS) Insulation potentially overlaps the sash of the window. Future removal of the glass is made difficult

55 mm

65mm of window frame is visible

Insulation and plasterboard cover the window frame

3D Visuals of a retrofitted solid wall:

Internal View

External view

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Section 3. Group Task Appendix This project will investigate these issues through building full-size mock ups to test solid wall insulation products and detailing of fixings, especially at junctions, to prevent thermal bridging. We will use information published in McKay (1938) to understand traditional construction methods.

“There are over 6 million pre-1919 dwellings in England with solid, load bearing walls. This traditional building pathology is different from cavity wall construction, in that they have to ‘breathe’. They are designed to let moisture in and out of the structure through porous and permeable materials such as lime mortars, renders and plasters.” (Jones.M, 2019) The introduction of impermeable membranes has proved to increase damp and condensation, causing mould growth. In addition poor detailing around junctions, such as window reveals/ floors/eaves and at foundation level, have resulted in thermal bridging and damp. Poor specification and poor workmanship have resulted in accelerating damage to the buildings and to the health of the inhabitants.

Constructing The Wall (Week 1):

The Equipment -Bricklaying trowel -Pointing trowel -‘Bucket handle’ curved jointer -Hand saw -Stanley Knife -SDS Drill -8mm Drill bit -Impact Driver -Dust mask -Shovel Materials -Sand -Lime -Anchor -Insulation -Engineering bricks

The Mix Every mix is an essential factor to this as slight inconsistencies in the ratio will alter the aesthetics of the mortar; it’s strength quality also in some instances, its warranties. In this case, a 3 - 1 ratio of sand to mortar is used.

Flemish Bond A Flemish bond is a traditional solid wall brick pattern. Firstly it needs to understand the names of each brick face and position.

The central part of the wall is Constructing The Wall (Week 2)

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made up of Header - Stretcher - header, with the next course above following this, however, the header on this course will sit in the middle of the Stretcher on the course below.

At the Corners of the build, you have a 1/4 brick missing; this is where a Queen closure is used. At the end of a wall, a King Closure is used to create the flush finish.

Bonded together with lime mortar as the wall must have excellent breathability as there isn’t a cavity.

Casting The Stone Cill

Preparing the mould The mould used must be cleaned thoroughly of any excess material from the previous casting to ensure a high-quality mix.

The mould is then cleaned of dust using an air compressor then wiped over with a rag. An application of oil is rubbed over the mould to help the cast to be removed once dry; this prevents the mix bonding with the mould itself.

Spacers are then used to ensure that the correct size mould is used these are cut precisely to the size requested.

The Mix A mix of very fine casting sand and white cement is mixed at a ratio of 3/1. Colour pigment is then added, once mixed thoroughly to ensure a high quality this is then placed into the mould. Where the mould is vibrated to remove any air gaps within. The top is then trowelled to create a smooth face on what will be the back of the cill.

Casting It is now that the cast is left to set for up to 5 days to ensure the cement has cured to strength good enough for transport.

Bedding The Cill (Week 3):

Ensuring that the window sat in the centre of the wall is a priority in order to guarantee a symmetrical pattern of bricks cut on both sides of the window.

The stone cill has been bedded with mortar, level, on the correct brick course. We are ensuring that the drip of the cill is extruding the external facade. To prevent any encouragement of water on the face of the wall, leading to problematic issues. The horns of the cill are required to be level

with the brickwork to allow the next course of brick to be bedded on top of them. In this case, a stone cill that has a join has been used to reduce cost, if not filled; This can attract water which could have effects on the wall such as damp and freeze thaw effect. An issue that should not be relevant in the industry.

Using a wooden frame as a template, the reveals of the wall around the window can be built level and square. The timber

is later replaced with the PVC window frame with a ‘stumpy’ cill.

This is to allow water to drip from the frame on to the stone cill.

Cutting the king closures soon became problematic; this is because we didn’t have a disk cutter necessary to cut precisely.

Using lump hammer and chisel, led to a few errors, this is noticeable on the widow reveal as some bricks are various sizes.

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Applying Insulation: “This project will investigate these issues through building fullsize mock ups to test solid wall insulation products and detailing of fixings, especially at junctions, to prevent thermal bridging. “ BRIEF QUOTE Now that the wall has been constructed it is critical that we investigate the problems that are insulating an inner wall face as the brief suggests.

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In this case, we concluded that we’d insulate the inner face (1) of the brick wall to reduce lateral heat loss. By doing this, it will make us aware of problems that the tradesmen face, also issues that reduce the thermal qualities of the product as a result of poor / inconsistent / incorrect application.

Applying the insulation to a dry wall is critical to prevent any trapped moisture. As this is a solid wall, using lime mortar, it is vital to use an insulation that matches the breathability of the wall.

If beathability is ignored, health issues will occur as well as further economic investment to correct the work. Using a natural material allows the wall to breathe and moisture mobility/transfer to continue.

The insulation is put into place and marked to the mortar joints (2) to provide an anchor point for the drill. Using the correct SDS drill bit (8mm in this case) a hole can be drilled to the proper depth noted on the specification of the plugs. Using a hammer persuade the plastic wall plug into place so that the head is flush with the face of the insulation (3). Again using a hammer, tap the screw with the plastic head into place (4). By putting the screw in place, this will open up the wall plug on the internal hole to secure a sturdy fixing (5). Repeat this as many times as the specification suggests.

When joining two panels of insulation together, use the tongue and groove provided to ensure a tight fit as well as eliminating a straight join that could be problematic if not closed as this provides a thermal bridge.

Problems that have been raised when internally insulating.

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- Window reveals they need to be insulated too to prevent heat transfer loss. This can be problematic as the thickness of the insulation may be greater than the width of the window frame. Either a new window will need to be fitted or thinner insulation to insulate the jambs of the windows. All four reveals must be insulated, tight fits and neat cuts are crucial at these junctions - In the corners of the wall, the insulation doesn’t have a fixing method, so it is up to the discretion of the tradesman to ensure a tight fit with no gaps. “3.10 The guidance given by English Heritage3 should be taken into account in determining appropriate energy performance standards for building work in historic buildings.”

(HM Government. 2010 pg 9) - Ensuring the next stage, workman uses a lime plaster to complete the interior finish. As the wall has been designed to breathe, especially with natural fibreboard insulation. If ignored, this will become problematic as health issues and damp will aspect the appearance of the wall.

-Some fixings were loose because of the weak mortar.

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Final Images:

Reflection: On reflection to constructing an insulating a solid brick wall, I feel that we have managed to achieve the right level of artistry. We have included all the details of a traditional pre-1919 solid wall using the Flemish brick bond pattern with a stone cill and detailing above the window frame. A few concerns with the brickwork itself, some of the mortar joints vary in size. An indication that various members of the group have all taken part in the construction of the wall, creating inconsistencies. On the one side of the wall, a few bricks are not level; on-site, this would indicate that there is subsidence or uneven brickwork. Also, there is inconsistency in the mortar, again problematic when working with different groups all having a go at mixing. The mortar would be critical to get right on-site as the strength and aesthetic properties would alter and not perform as intended. A qualified bricklayer would rectify all of the above (one would hope!)

Insulating - I feel that we have achieved a high standard of insulation with no gaps present where panels meet each other, plus insulating all four reveals of the window. A point to consider in the industry would be to have a plastic corner to ensure that there are no gaps in the insulation that can lead to thermal bridging. Also raising the question, how should the insulation sit on the floor? To ensure airtightness, the perimeter of the window frame has been siliconed into place. If this was an enclosed model tests could have been carried out to assess air tightness and R-values.

Lastly, the tools used - by not having all of the correct equipment needed it allowed for mistakes and some neat work, this then took time to rectify. however this made the outcome slightly more realistic as errors, and some poor craftsmanship would be expected on site.

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Section 4.1. Site Visit - Lime Manufacturer (Lime Green, Much Wenlock, Shropshire) Why Buy an all in one product?

Mixed on-site , Accuracy is higher with the use of scales and computers; this improves performance and consistency. Provides a guarantee for the product. it is a sophisticated process allowing various additives can be added such as fibres, as well as bespoke mixes.

Lime Manufacture Factory

Computer System

Gravity Fed

Gravity Fed Mixer

This is a new factory that has been built to be self-efficient, sustainable and to encourage a better work flow. How has the factory been designed to be sustainable?

A computer weighing system avoids any human error when weighing out components.

This system can be easily edited to adapt to a new mix. This sophisticated program allows the employee to monitor levels of materials to keep a good stock flow.

This photo shows the gravity-fed system, above all these pipes leading to the mixer, is multiple Ceylon’s that contain various materials that are used for the mixes.

With one mixer, this means that the Maintenance team need to clean it after every mix to ensure that there is no crosscontamination between combinations. This is necessary to provide a guarantee on all of the products produced.

Quality Control

Insulation Fixings

External Render

-Samples are kept from each batch for future testing -Provides a guarantee/ warranties for the product -Its a Traceability aspect for the company

The fixings are counter Sunk into the insulation this is to prevent; Thermal transfer via a thermal bridging (Metal Screw) Condensation transfer Screws used with a plastic cap on the top

to prevent transfer. The component casing is plastic.

The countersunk hole is then plugged with insulation to prevent and cold spots and bridging; this also prevents rust as well as condensation transfer.

-Solar panels on the roof outperform the electric usage within the plant, creating a positive payback to the grid.

-High-efficiency Machines -LED Lighting -Louvre ventilation to avoid the need for Mechanical.

-A closed System

Quality Control

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Section 4.2. Site Visit - College Precincts (Worcestershire) *Grade 1 Listed Buildings*

The pourpose of the site visit was to look at traditional wall construction details and to take measurements for window reveals, cills, lintels and door openings.

Expansion joint

Poor Craftsmanship

An expansion joint has been designed into the wall construction, how ever the joint has been filled with mortar and not a flexible and waterproof silicone.

Depending on if the joint has been finished with a cement or lime-based mortar, will depend its characteristics when there is movement.

In this case, a horizontal hole has been drilled to feed a TV cable inside this building.

Problematic as three holes have been drilled for one cable, reducing airtightness and creating a thermal bridge between interior and exterior. Also, there has been no attempt to seal the holes; this means that water/

College Precincts

Traditional Wooden Frae

condensation is

Vegetation Forming (Possible Damp)

Allowed to run along the cable to the interior wall finish. If correctly fitted it would have been patched with lime mortar as well as a plastic disk to provide a drip around the cable

No window cills are providing a drip to prevent damp. As a result of this, the wall has got noticeable growth on it; this is alerting as it means the wall is damp, which if in excess will affect the internal finish of the walls.

Rowing Club

College Precincts

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Section 6: Bibliography Baker-Brown, D (2019) The Re-use Atlas. 2nd edn. London: RIBA. BBC News (2019) Parliament declares climate change emergency.

Available at: https://www.bbc.co.uk/news/uk-politics-48126677 [Accessed 23 November 2019].

Bristol City Council (n.d.) A Bristolians guide to Solid Wall Insulation. Bristol: Bristol City Council.

Dollard, T. (2018) DESIGNED to PERFORM. London: RIBA Publishing. .

Dollard, T. and Edwards, P. T. (2015) Builders Book. [Online] Available at: www.Zerocarbonhub.org [Accessed 20 October 2019].

Eco merchnt (n.d.) Insulation materials compared. Avalible at: https://www.ecomerchant.co.uk/news/insulationmaterials-compared/ [Accsessed 11 December 2019] English Heritage (2008) Energy Conservation in traditional buildings. London: English Heritage.

Historic England (2016) Energy Efficency and Historic Building, Insulating Early Cavity Walls. London: Historic England.

Historic England (2016) Energy Efficiency and Historic Buildings, Insulating Solid Walls. London: Historic England.

Historic England (2011) Energy Efficiency and Historic Buildings - Application of Part L of the Building Regulations to historic and traditionally constructed buildings. London: Historic England.

Historic England (2012) Energy Efficiency and Historic Buildings. London: Historic England.

Historic England (2016) Energy Efficiency and Historic Building, Insulating Solid Ground Floors. London: Historic England.

HM Goverment (2010) The Building Regulation 2010, Conservation of fuel and power L1B. Online edn. London: UK Goverment.

Historic England (2016) Energy Efficiency and Historic Builings, Draught-Proofing Windows and Doors. London: Historic England.

Hunt, R. (2014) S.P.A.B BRIEFING: Energy efficiency in old buildings. London: Pensord.

Hunt, R. and Boyd I. (2017) New design for old buildings. Newcastle Upon Tyne: RIBA Publishing.

Jones, m. (2019) Assignment Brief, Technical Investigation ARC6012. Birmingham: BCU. Killip, G. (2008) Transforming the UK’s Existing Housing Stock. [PDF] A report for the Federation of Master Builders. Oxford: University Of Oxford. Avalible at: https://www.ciob.org/sites/ default/files/FMB%20Building%20A%20Greener%20Britain.pdf [accsessed on 10 December 2019] Morgan, C. (n.d.) Design and Detailing For Airtightness - SEDA Design Guide For Scotland. CITY: SEDA. Morgan, C. (n.d.) Design For Deconstrution. Glasgow: SEDA. Morgan, C. (n.d.) Sustainable Renovation. Glasgow: SEDA. Pelsmakers, S. (2015) Enviromental Design Pocket Book. 2nd edn. London: RIBA. The Green Age (2015) Why did the green deal fail? Availible at: https://www.thegreenage.co.uk/why-did-thegreen-deal-fail/ [Accsessed on 14 December 2019].

UK Green Building Council (2019) UKGBC’s vision for a sustainable built environment is one that mitigates and adapts to climate change. Avalible at: https://www.ukgbc.org/climate-change/ [Accsessed on 10 December 2019] UN Environment Programme (2019) Emissions Gap Report 2019. [pdf] Available at: https://www.unenvironment. org/resources/emissions-gap-report-2019 [accessed on 13 December 2019] 25

Figures: Figure 1: Cooksey, R. (2019) Outside elevation of the group task; solid brick wall using the Flemish brick bond,

laid on lime mortar. PVC window frame sits above A traditional stone cill. Bridged with a flat steel lintel and Headers for ornament. Photo: Author myself.

Figure 2: UN Environment Programme (2019) Emissions Gap Report 2019. [pdf] Available at: https://www. unenvironment.org/resources/emissions-gap-report-2019 [accessed on 13 December 2019] adapted by author Figure 3: Crocker, T. (2019) A street photograph of Goldsmith Street, Norwich Avalible at: https://newatlas.com/ architecture/2019-stirling-prize-goldsmith-street/ [accsessed 10 December 2019].

Figure 4: Right Move (2019) A street photograph of College Precincts, Worcster. [Photograph] Photography by Free Agent 247. Avalible at: https://www.rightmove.co.uk/property-for-sale/property-85628714.html [Accsessed 10 December 2019].

Figure 5: What are the other methods of increasing energy efficiency. Table by Author.

Figure 6: Highlighing possible retrofitting techniques for a solid wall dwelling.

Bristol City Council (n.d.) A Bristolians guide to Solid Wall Insulation. Bristol: Bristol City Council. Adapted and changed by author.

Figure 7: Identifying Pros / cons of Internal/External insulation: Bristol City Council (n.d.) A Bristolians guide to Solid Wall Insulation. Bristol: Bristol City Council. Adapted and changed by author.

Figure 8: permeable and non-permeable materials. Table by Author.

Figure 9: How does damp transfer. Technical detail by Author.

Figure 10: Consequences of condensation leading to damp. The Irish Times (2016) Damp attacking the wall at a window: a poorly heated house will naturally be more susceptible to condensation. Avalible at:https-// www.irishtimes.com/life-and-style/homes-and-property/how-do-i-tackle-damp-patches-and-mould-1.2811904 [Accsessed 11 december 2019].

Figure 11: 3D Model of a insulation anchor junction. Visual by Author.

Figure 12: An insulation anchor junction. Technical detail by Author.

Figure 13: Heritage House (2019) Thermo window picture. Avalible at: https://www.heritage-house.org/buildingsurveys/thermal-imaging-surveys/heat-loss-around-windows.html. [Accsessed on 09 December 2019]. Text by author Figure 14: Debris from Construction of internal insulation. Avalible at:https-//www.diynot.com/diy/threads/ [Accsessed on 01 December 2019].

Figure 15: A 3d model of a section through a solid wall, presenting a window / insulation junction at the reveals.

Visual by Author.

Figure 16: Section- Insulating a problematic window junction. Technical detail by Author.

Figure 17: Gaps in the insulation at corner joints. Photograph by Author.

Figure 18: Slight gaps in tounge and groove syterm. Photograph by Author.

Figure 19: Problematic junction, there isnt a corner insulation systerm. Photograph by Author.

Figure 20: Assessing the value of retrofitting with an economic eye . By Author but adapted figures from: Pelsmakers, S. (2015) Enviromental Design Pocket Book. page. 292 2nd edn London: RIBA. Figure 21: Steps to consider before retrofitting. Table Author. .

Figure 22: The guardian (2016) Green deal scheme did not deliver energy savings, audit finds Since their launch in 2013, ECO and the Green Deal have delivered significantly fewer measures then previous schemes. Avalible at: https://www.theguardian.com/environment/2016/apr/14/green-deal-scheme-did-not-deliver-energy-savingsaudit-finds [accsessed on 14 December 2019].

Appendix: *All work, Technical Drawings, Tables, Photographs and images are Produced by Author and members of the group task stated on the Appendix cover.* 26

This article focuses on the question, should older buildings

(Pre 1919) be retrofitted? In the introduction I will be discussing the need for insulating older buildings and why the need for retrofitting has become topical. In the next section I will look at a case study to understand the use of a traditional form in a highly efficient new housing scheme. This leads on to a discussion on improving thermal performance as well as the effects of craftsmanship.

Followed by an investigation narrated in the form of an appendix. In this case the investigation was to retrofit the problematic junction of a window. Prior to the task, in order to understand the importance of breathability as a group we visited a lime manufacturer and college road, worcestershire this was to then inform the group model.

Birmingham City University S17123027 ARC6012 , Level 6 Technical Investigation 16 December 2019