Department of Building and Civil Engineering
A Dissertation Submitted in Partial Fulfillment for the Requirements Of BSc. (Hons) Architectural Technology 2012
Study into the Internal Retrofitting of Walls in Traditional Irish Buildings for Improved Thermal Performance
By Alan Dennehy
Acknowledgments I would never have been able to finish my dissertation without the guidance of my supervisor and lecturers, help from my close friends and classmates and support from my family. I would to express my deepest gratitude to my supervisor, Mr. Sean Moloney, for his excellent guidance and for taking his time to read and correct my work for this dissertation throughout the year. Also I would like to thank my lecturers Ms. Denise Dillon and Ms. Emer Maughan not only their help and guidance this year but for all the previous years that I have had them as lecturers. I would like to thank Mr. Niall Crosson of Ecological Building Systems for carrying an interview with me and the Kilkishen Church Restoration Committee for allowing access to the church to carry out a case study. Finally I would like to give a special thanks to my parents. This proved to be a very challenging and difficult four years of study and they were always there supporting me and encouraging me with their best wishes.
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Plagiarism Declaration Name: Alan Dennehy Dissertation Title
Plagiarism consists of a person presenting another person’s ideas, findings or work as one’s own by copying or reproducing the work without due acknowledgement of the source. Plagiarism is the theft of intellectual property. The Institute regards plagiarism as a very serious offence. At the very least, it is a misuse of academic conventions or the result of poor referencing practice. Where it is deliberate and systematic, plagiarism is cheating. Plagiarism can take several forms, examples of which are given below: a. Presenting substantial extracts from books, journal articles, thesis and other published or unpublished work (e.g. working papers, seminars and conference papers, internal reports, computer software, lecture notes or tapes, and other students’ work) without clearly indicating the source of the material; b. Using very close paraphrasing of sentences or whole paragraphs without due acknowledgement in the form of reference to the original work; c. Quoting directly from a source and failing to insert quotation marks around the quoted passages. In such cases it is not adequate merely to acknowledge the source; d. Copying essays or essay extracts or buying existing essays from Internet websites or other sources; e. Closely replicating the structure of someone else’s argument without clear reference to the source. The Institute is committed to detecting all cases of student plagiarism. All cases will be dealt with in accordance with the Institute’s Examination Regulations: Penalties for plagiarism include: a. Awarding lower marks or no marks for the dissertation; c. Awarding a lower class of degree or other academic award; d. Excluding the student from the award of a degree or other academic award, which may be either permanent or for a stated period. Your signature: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Abstract Throughout Ireland there are fine examples of traditional solid stone buildings, from rural cottages to old churches. Every effort must be made to make these historic buildings more efficient while maintaining their aesthetic and historic values, as energy efficiency and the fight to reduce CO2 emissions is a major issue in Ireland today. This dissertation investigates the different options available to improve the efficiency of walls internally in traditional Irish buildings. The study was carried out by analysing the available publications together with an interview with a professional in the field and a case-study of an historic construction. The different retrofit options that are investigated are not just judged on the thermal efficiency of the walls after upgrading but on their impact on the building as a whole. Conservation principles play a major role in determining the retrofit option that is used, thus ensuring that there is minimal interference with the existing building fabric.
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
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Alan Dennehy BSc. (Hons) Architectural Technology
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Table of Contents Acknowledgments .................................................................................................................... i Plagiarism Declaration ............................................................................................................. ii Abstract.................................................................................................................................. iii List of Definitions .................................................................................................................. viii 1.
2.
3.
Introduction ..................................................................................................................... 1 1.1.
Definition of Topic .............................................................................................................. 1
1.2.
Hypothesis of the Study ..................................................................................................... 1
1.3.
Research Methodology ...................................................................................................... 2
1.4.
Building Retrofit ................................................................................................................. 2
1.5.
Energy Efficiency ................................................................................................................ 3
Traditional Solid Stone Walls and their Characteristics ...................................................... 4 2.1.
Traditional Solid Stone Walls ............................................................................................. 4
2.2.
Breathability ....................................................................................................................... 5
2.3.
Thermal Mass ..................................................................................................................... 6
2.4.
Thermal Bridges ................................................................................................................. 7
2.6.
Financial Cost and Payback .............................................................................................. 10
2.7.
Cost Effectiveness ............................................................................................................ 10
2.8.
Environmental Influences ................................................................................................ 10
2.9.
Conservation .................................................................................................................... 11
Solid Wall Insulation ....................................................................................................... 13 3.1. Solid Wall Insulation ............................................................................................................. 13 3.2. Internal Insulation ................................................................................................................ 13 3.2.1. General .......................................................................................................................... 13 3.2.2. Directly applied internal insulation ............................................................................... 14 3.2.3. Internal Insulation with Studwork................................................................................. 14 3.2.4. Physical Adaptation of the Building .............................................................................. 15 3.2.5. Changes in Appearance and Character of a Building .................................................... 15 3.2.6. Changes in Moisture Movement within Wall............................................................... 16 3.2.7- Materials ........................................................................................................................ 17
4.
Natural Insulation........................................................................................................... 18 4.1.
General ............................................................................................................................. 18
4.2.
Products ........................................................................................................................... 19
Edenbloc 35 .............................................................................................................................. 19 v
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Thermafleece Wool Insulation ................................................................................................. 20 Calsitherm Climate Board ........................................................................................................ 21 Pavadentro ............................................................................................................................... 22 5.
U-Values and the BER’s ................................................................................................... 23 5.1 U-Values ................................................................................................................................ 23 5.1.1.
U-Value Calculation Method .................................................................................... 23
5.1.2.
Builddesk Software................................................................................................... 23
5.1.3.
Assumptions for U-value Calculations ..................................................................... 24
5.2. Building Energy Rating (BER) and Traditional Buildings ....................................................... 25 6.
7.
8.
Interview: Niall Crosson, Technical Engineer, Ecological Building Systems ........................ 28 6.1.
Mr. Niall Crosson- Background......................................................................................... 28
6.2.
Ecological Building Systems- Background ........................................................................ 28
6.3.
Interview Findings ............................................................................................................ 29
Case Study: Kilkishen Church .......................................................................................... 32 7.1.
Building Background ........................................................................................................ 32
7.2.
Walls Surveyed ................................................................................................................. 32
7.3.
Legislation Protecting Kilkishen Church ........................................................................... 34
7.4.
Description of Data Collected .......................................................................................... 34
Analysis of Thermal Retrofit Measures to Traditional Solid Stone Walls ........................... 36 8.1. Analysis of Existing Walls at Kilishen .................................................................................... 36 8.2.
8.2.1.
Proposed Wall 01- Calsitherm Climate Board .......................................................... 37
8.2.2.
Proposed Wall 02- Edenbloc 35 ............................................................................... 38
8.2.3.
Proposed Wall 03- Thermafleece EcoRoll ................................................................ 39
8.2.4.
Proposed Wall 03- Pavadentro ................................................................................ 40
8.3. 9.
Analysis of Proposed Wall Solutions ................................................................................ 37
Comparison of Proposed Retrofits ................................................................................... 41
Conclusions .................................................................................................................... 43
References............................................................................................................................. 45 Appendices ............................................................................................................................ 48 Appendix A:
Interview Questionnaire for Mr. Niall Crosson, ................................................... 48 Technical Engineer at Ecological Building Systems .............................................. 48
Appendix B:
Kilkishen Church-Case Study ................................................................................ 50
Appendix C:
Planning & Conservation Report from Clare County Council .............................. 60
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List of Figures Figure 1 Visual Example of a Solid Stone Wall ................................................................................... 5 Figure 2 Graph showing temperature changes within buildings with high thermal mass and with low thermal mass ............................................................................................................................... 7 Figure 3 Diagram describing how Calsitherm system works .......................................................... 21 Figure 4 Diagram showing how the Pavadentro system works ...................................................... 22 Figure 5 Traditional solid wall construction: left figure shows a schematic diagram of a rubbe wall construction with 40% mortar; and the right figure shows its representation as two laters for modeling .......................................................................................................................................... 24 Figure 6 Example of a BER Certificate .............................................................................................. 27 Figure 7 Plan of Kilkishen Church .................................................................................................... 33 Figure 8 Section through existing wall with Calsitherm system ..................................................... 37 Figure 9 Section through existing wall with Edenbloc35 system .................................................... 38 Figure 10 Section through existing wall with EcoRoll system ......................................................... 39 Figure 11 Section through existing wall with Pavadentro system .................................................. 40
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Alan Dennehy BSc. (Hons) Architectural Technology
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List of Definitions Acoustic: Relating to sound or the sense of hearing. AutoCad: a software application for computer-aided design (CAD) and drafting, in both 2D and 3D formats. Breathable: allowing air to pass through. Building Energy Rating (BER): an indication of the energy performance of a building. Calcium Silicate:
any of several silicates of calcium used especially in construction
materials. Cellulose:
is the raw material of many manufactured goods (as paper, rayon, and
cellophane). Condensation: the conversion of a substance (as water) from the vapor state to a denser liquid or solid state usually initiated by a reduction in temperature of the vapour. Conservation: Action taken to prevent the decay of historic building elements. Damp Proof Course: a course of some impermeable material laid in the foundation walls of building near the ground to prevent dampness from rising into the building. Diffusion: the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration. Emissivity: the relative power of a surface to emit heat by radiation : the ratio of the radiant energy emitted by a surface to that emitted by a blackbody at the same temperature. Homogeneous: of uniform structure or composition throughout. Hygroscopic: readily taking up and retaining moisture. Ingress: the act of entering
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Interstitial Condensation: condensation forming within a layer of the wall. Micro-climate: the essentially uniform local climate of a usually small site or habitat. Permeable: having pores or openings that permit liquids or gases to pass through. Relative Humidity: the ratio of the amount of water vapour actually present in the air to the greatest amount possible at the same temperature. Rubble: Pieces of rough or undressed stone used in building walls, especially as filling for cavities. Specific Heat Capacity: the amount of heat energy required to raise the temperature of a body per unit of mass. Studwork: The supportive framework of a wall or partition. Taper: to become progressively smaller toward one end. Thermal Conductivity: is the property of a material's ability to conduct heat. Thermal Insulation: material of relatively low heat conductivity used to shield a volume against loss or entrance of heat by radiation, convection, or conduction. Trickle Vent: opening in a window or other building envelope component to allow small amounts of ventilation in spaces intended to be naturally ventilated when major elements of the design - windows, doors, etc, are otherwise closed. U-Value: Measure of thermal transmittance through materials, measured in W/m²k. Vapour Barrier: a layer of material used to retard or prevent the absorption of moisture into a construction. Ventilation: a system or means of providing fresh air.
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1.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Introduction
This chapter introduces the area of study and outlines the direction and methods of research.
1.1. Definition of Topic The following dissertation; Study into the Internal Retrofitting of Walls in Traditional Irish Buildings is a study into the characteristics of traditional rubble fill walls in Ireland and how these buildings can be retrofitted effectively internally. The study will assess the feasibility and effectiveness of modern methods and modern materials that can be used to retrofit this type of wall construction. This is a relevant choice of study due to the importance of preserving Ireland’s rich architectural heritage in the form of Ireland’s many buildings built using natural solid stone while at the same time conserving energy. These buildings external façade showed be maintained at all costs and looking into internally retrofitting these building is an ideal way of maintaining the external aesthetics of these buildings. The studies significance is based on thermally improving walls and thus minimising energy use. Energy consumption has become a major topic in the past decade and a huge effort is being made to reduce our CO2 emissions. Under the Kyoto Protocol, Ireland must limit the growth in its emissions to 13% above 1990 levels over the 2008-2012 period. Measures already in place and additional measures outlined in the Strategy will effectively reduce our overall emissions from almost 80 million tonnes of CO2 equivalent per year to our Kyoto target of 63 million tonnes (Department of the Environment and Local Government 2007). Also under the EU Services Directive, member states must improve their energy efficiency by 9% by 2016 (European Commision 2006). 1.2.
Hypothesis of the Study
The study is based on the hypothesis that ‘As a result of an effective retrofit can a traditional stone wall achieve an A-rated U-Value’.
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Alan Dennehy BSc. (Hons) Architectural Technology
1.3.
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Research Methodology
Research includes a study of appropriate peer reviewed literature and studies already carried out regarding traditional solid stone walls under the characteristics of these walls, conservation principles and retrofit measures available to improve their thermal performance. A case study was carried out on a protected structure; Kilkishen Church, which is built with solid stone rubble-fill walls dating back to 1811. Using the church as a case study ensures both modules are integrated. Protecting legislation and conservation guidelines specific to the walls were established. Then, different proposals for improving the walls thermal properties were assessed under thermal performance and compliance with appropriate conservation guidelines. An interview was carried out with the Technical Engineer at Ecological Building Systems Ltd.; Mr Niall Crosson. The company specialises in the upgrading of the thermal performance in historic buildings and particularly in the use of natural insulation.
1.4.
Building Retrofit
In basic terms a retrofit is when something is fit with a component or accessory that was not fitted during manufacture (Oxford Dictionary 2001). So in turn a building retrofit can be seen as, an improvement of the infrastructure of the building to increase its energy efficiency, comfort, safety, health and durability. This could include improving building components, operating systems and equipment, and installing energy efficient appliances (Retrofit Boston October 2010).
Why Retrofit Buildings? The Built Environment accounts for 40% of the EU’s greenhouse gas emissions. Therefore, the Built Environment plays a major role in both the problem and the solution of climate change (Clinton Climate Initiative 2011). There are financial gains to be made in the form of reductions in energy costs if the retrofitting is carried out effectively, although the reduction in energy cost can be spread out over a long period of time.
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
The recent introduction of Building Energy Ratings (BER) in Ireland further promotes the retrofitting of existing buildings. These ratings will allow potential buyers to compare the energy efficiency of buildings before they buy them. This leaves newly built houses at a great advantage due to their superior performance and energy efficiency levels, compared to existing buildings. The only way in which the existing structures can combat this is through energy efficient retrofits so that they too can also achieve respectable BER ratings (English Heritage Feb 2010).
1.5.
Energy Efficiency
Energy efficiency can be defined as the ratio between the output of performance, service, goods or energy and an input of energy. Something is energy efficient when; it can achieve the same results with less energy or when it can achieve improved results without an increase in energy input (Sustainable Energy Ireland 2009).
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
2. Traditional Solid Stone Walls and their Characteristics 2.1.
Traditional Solid Stone Walls
Traditional or historic solid walls have very different characteristics to what we are used to seeing in modern day cavity wall construction. Many of these older buildings can have up to three of four different wall types due to development in construction techniques over many years. Solid walls can vary from single skin brick or stone of 100mm thickness to rubble-filled walls of a metre or more in thickness (English Heritage Feb 2010). Traditional masonry walls of stone do not contain a cavity. In stone construction, the core or central portion of the wall was often filled with small stones and lime mortar. Rubble walls were generally rendered externally in a breathable lime plaster but there is also a lot of examples of the natural stone being left exposed externally. Solid stone rubble fill walls relied on their thickness to cope with atmospheric moisture, being sufficiently thick to ensure that drying out took place before moisture from rainwater passed through the wall to cause damp on the inner face. The breathable lime plaster allowed the moisture in the walls to dry out to the external air. Virtually all buildings constructed in this country before 1940 were built of this type of masonry construction. The use of lime extended to other components of the building; older buildings are often found to have lime pugging between the joists in the floor, providing additional thermal and acoustic insulation. Many traditionally built buildings are protected structures under the Planning and Development Acts, and therefore are identified as being of special interest. However, there are many other traditionally built buildings that do not have statutory protection but may nonetheless be worthy of care in their repair and enhancement for contemporary living (Dept. Of Environment Heritage and Local Government 2010).
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Figure 1 Visual Example of a Solid Stone Wall
Source: (Changeworks 2008)
2.2.
Breathability
Breathability is a major factor in the construction of traditional stone buildings. Construction incorporated the use of porous materials and natural ventilation which ensured the buildings were able to breathe. These old buildings did not incorporate any barriers to external moisture such as rain screens, damp proof courses or vapour barriers and membranes which are standard in modern construction. The use of breathable materials allows for the exchange of moisture readily with the indoor and outdoor environments (Changeworks 2008). Thorough understanding of the buildings unique environmental characteristics will avoid detrimental effects to building’s breathability caused by misguided material changes (Energy Saving Trust 2008a). When it comes to upgrading or retrofitting an existing building the most important thing is to maintain breathability. Any non-breathing
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
material added will only hinder its ability to breathe and regulate moisture. Any modern materials being added must be chosen Breathability of walls in traditional buildings in particular the behavior of liquid water and water vapour, and in turn, their effects on other aspects of the performance of both the building envelope and the internal environment, is a complex matter (English Heritage 2011). When the construction of these traditional stone buildings are working as they were designed to, evaporation will keep dampness levels in the building’s fabric below the levels at which decay can start to develop. If these old structures are properly maintained, a breathing building has definite advantages over a modern impermeable building (English Heritage Feb 2010).
2.3.
Thermal Mass
Thermal mass can be defined as the ability of parts of a dwelling with a high specific heat capacity, such as brick or solid stone, to store excess heat within a building and release it at a later time (Energy Saving Trust Feb 2010). This process is known as Thermal Inertia (Dept. Of Environment Heritage and Local Government 2010). During summer months strong sun causes overheating and in turn the thermal mass of the walls cools the interior by absorbing excess heat during the day and releasing it slowly during the night. Effective absorption and release of this heat will reduce the need for air conditioning or mechanical cooling (English Heritage Feb 2010). During the winter periods the thermal mass of the building can be used to supplement some of the space heating requirements. For this to work effectively buildings need to have a significant proportion of glazing that face the sun at some point during the short winter day (Energy Saving Trust Feb 2010). The possibility of exploiting solar gain in a building of high thermal mass is optimized if the building is occupied during daylight hours so that occupants can take full advantage of the free heat stored (Dept. Of Environment Heritage and Local Government 2010). When it comes to refurbishment and improving overall levels of insulation, great consideration should be given to allowing materials with high specific heat capacity to remain in contact with the air inside the dwelling. It is inherently more difficult to provide 6
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
thermal mass to existing buildings so any opportunity to make use of the existing thermal mass should be considered whenever it is possible (Energy Saving Trust Feb 2010). Traditional buildings tend to always have a high thermal mass but occupants frequently fail to exploit this potential. If one was to address these shortcomings, traditional buildings could have more desirable qualities and could efficiently provide comfort and warmth for their occupants (Dept. Of Environment Heritage and Local Government 2010).
Figure 2 Graph showing temperature changes within buildings with high thermal mass and with low thermal mass
Source:(Dept. Of Environment Heritage and Local Government 2010)
2.4.
Thermal Bridges
A thermal bridge can be defined as a region within a building element where the transfer of heat is higher than in other parts of the same element. Severe thermal bridges can lead to mould growth or condensation (Energy Saving Trust 2008b). When insulation is added to existing buildings, there is a danger of creating thermal bridges at critical details where
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
full insulation coverage may be interrupted. For instances where external insulation is used weak points are typically at window and door reveals, and for instances where internal insulation is the method used weak points are commonly found where floors meet the external walls (English Heritage Feb 2010). Areas with reduced or no insulation coverage will not only be colder because of lack of protection from the outside environment but will also attract relatively more condensation because the majority of the surfaces are warmer and can no longer share the moisture load. The result can be severe local decay, particularly to timber and finishes. A primary example where decay from condensation can occur is at the ends of floor joists embedded in the external walls (English Heritage Feb 2010). The severity of thermal bridging will increase if the insulation value of the main body of a construction element is high. Adding additional insulation although it may seem appropriate will increase the risk of localized damp and construction failures in less insulated components which bridge this layer (English Heritage 2011). When it comes to thermal bridging great care must be taken to ensure adequate detailing is achieved around window and door openings to avoid potential defects. This will significantly increase the overall cost of both design and installation. The necessary level of detailing can even be impossible to incorporate in certain circumstances. In such cases depending on the potential severity of the consequences, it may be more beneficial not to install insulation at all (English Heritage Feb 2010).
2.5.
Damp
If a wall suffers from prolonged dampness the following problems can occur such as:
Decay in timbers in contact with the masonry
Deterioration of the external fabric of the wall due to freezing and thawing
Movement and crystallization of salts
Growth of mould on the inside surface of walls 8
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Alan Dennehy BSc. (Hons) Architectural Technology
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Movement of tars and other chemicals through the walls, causing staining at the surface
Corrosion of metallic compounds in contact with, or buried within, the wall
Before making any improvements it is therefore important to understand how solid walled buildings ‘manage’ the movement of water, in both vapour and liquid form. Most insulation systems are designed and developed solely to limit heat loss and to avoid interstitial condensation from water vapour generated internally. System designs do not take into account the movement of water and salts already in a traditional wall. As a result of this the following issues may arise:
Exacerbate existing problems;
Create new problems, such as the displacement of damp and salts and the decay of timbers in contact with the walls;
Create health risks for the occupants, e.g. from mould growth;
Be affected by the moisture thus reducing their performance and in some cases failing entirely.
Where walls have been damp for a long period of time it can take years for them to dry out. The selection and design of insulation must take account of the drying-out process, both before and after installation, and the presence of residual damp and salts (English Heritage Feb 2010). Rising damp is another common problem. Traditional buildings deal with rising damp surprisingly well. This is achieved mainly by balancing the capillary water ingress with suitable evaporation to keep overall moisture levels within tolerable limits. When the original structure is altered problems tend to arise, for example when ground levels are raised, impermeable materials such as cement renders are added, or when the building is converted for more intensive uses. When excess damp penetration occurs it is often due to lack of maintenance such as open joints in masonry, which can encourage water ingress. This but can be effectively resolved by normal maintenance such as repointing work.
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Dampness causes increased heat loss through the fabric and prevents moisture buffering in internal spaces making buildings feel cold and clammy (English Heritage 2011).
2.6.
Financial Cost and Payback
The addition of external or internal insulation to solid walled buildings tends to be expensive and financial payback times are potentially correspondingly long. It is important not to underestimate the costs associated with the necessary levels of care in detailing, to avoid cold bridges. Full payback periods are typically 30 years or more, but they will inevitably vary greatly between individual instances. This suggests that in the majority of cases it would not be worth considering the insulation of external walls until the full range of easier and more immediately rewarding upgrades to traditionally-constructed buildings have been carried out. These would include actions such as repairing and draught-stripping windows and doors, insulating roofs and suspended ground floors, and possibly even installing condensing boilers. Significantly, most of these upgrades will also have considerably fewer detrimental effects on the character and cultural significance of historic buildings (English Heritage Feb 2010).
2.7.
Cost Effectiveness
The necessity to achieve good building detailing to perimeters and openings can significantly add to the initial base cost of both external and internal insulation and may significantly reduce its overall cost-effectiveness (English Heritage Feb 2010).
2.8.
Environmental Influences
Location, aspect, and the differing exposure of individual elevations to direct sunlight and wind driven rain have important influences on a building’s condition and performance, which need to be taken into account when making alterations. Different parts of a building are affected by very different micro-climates. For example, north facing elevations can be subject to prolonged damp as they do not receive the 10
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Alan Dennehy BSc. (Hons) Architectural Technology
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
benefit of a drying sun and are usually sheltered from drying winds. However, they receive little driving rain from the prevailing south-westerly winds, so conditions are more stable over time. This often means that north-facing walls deteriorate less than south and south-west facing walls which tend to suffer from accelerated rates of decay caused by fluctuations in temperature and regular wetting and drying cycles. Each building’s exposure to the elements is as much influenced by the proximity and position of surrounding buildings and its own projections and extensions as by the exposure of the site. For example, an apparently homogeneous terrace of houses can be affected by quite widely varying local levels of exposure and shelter. Such complex variations in microclimate would ideally need to be taken into account in the design of any insulation (English Heritage Feb 2010).
2.9.
Conservation
We look after our historic buildings not only for ourselves but for those who will come after us. Many of these buildings have been around for generations before us and it is our responsibility to hand them on in good condition to allow future generations to enjoy them too. It is important to understand some of the basic principles of good building conservation so that the works you undertake do not damage the special qualities of a historic building. Many of these are common-sense and all are based on an understanding of how old buildings work and how, with sensitive treatment, they can remain special. Before you start learn as much as you can about your particular building - what is its history and how has it changed over time? Remember that later alterations may be important too and evidence that the building has been cared for and adapted over the years with each generation adding its own layer to a unique history. When carrying maintenance and repair work the following guidelines should be adhered to as much as possible:
It is important to get independent advice from professionals in the field;
It is also important to establish and understand the reasons for failure before undertaking repairs; 11
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Parts of a building should always be repaired rather than replaced unless they can no longer do the job they were designed to do;
The correct materials and repair techniques are used and that even the smallest changes that are made to the building are carried to highest standards.
Techniques used should be easily reversed or undone. This allows for any unforeseen problems to be corrected in future without damage to the special qualities of the building.
All repair works should benefit future owners.
Only do as much work to the building as is necessary, and as little as possible.
Problems should be considered in the context of the building as a whole rather than in isolation.
If using architectural salvage from elsewhere care should be taken that the materials being used has not caused the destruction of other old buildings or been the result of theft. (Dept. Of Environment Heritage and Local Government 2010)
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3.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Solid Wall Insulation
3.1. Solid Wall Insulation Heat loss through an uninsulated solid wall is 50% greater than the heat loss through an uninsulated cavity wall. Refurbishing solid wall structures, in an energy efficient way, raises problems for specifiers. The most popular way to improve solid walls energy efficiency is to add insulation either externally or internally, both have their advantages and disadvantages. If wall are to be re-rendered it would make sense to add external insulation. An added advantage of this would be that work could be carried out while the building is occupied. On the hand, if major works are being carried out inside, internal insulation would be a better choice (Energy Saving Trust Feb 2010).
3.2. Internal Insulation 3.2.1. General It is extremely important that internal walls are investigated with care in advance of work or changes. Timber paneling, plaster mouldings or enriched decorations are all-important and need to be preserved. Where little or none of the original plaster survives and where complete re-plastering is required there may be an opportunity incorporate internal insulation (English Heritage 2011). In most cases insulation is applied directly to the inner face of the external wall and a finish is then applied to the room side. The most simplified method of internal insulation is the use of plasterboard with foam insulation backing fixed to the inner face of the external wall. However, this kind of system does not offer great insulating performance overall because of their depth. For significant thicknesses a non-rigid material can be fixed between timber studs or battens with the timber frame erected internally and fixed to the external wall with a new finish applied to the timber structure. Sometimes a timber frame with insulation is erected as a separate inner leaf with a cavity between the
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Alan Dennehy BSc. (Hons) Architectural Technology
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insulation and the existing external wall. It is very important that this cavity is ventilated (English Heritage Feb 2010). In all cases great consideration should be given to the control of vapour from the warm internal air entering and condensing within the insulation or within the vulnerable parts of the solid wall. The upgrading of the interior of existing walls will alter an internal room to varying degrees depending on the level of finish. It can be very intrusive and is rarely appropriate for traditional buildings with interiors of architectural significance (Dept. Of Environment Heritage and Local Government 2010).
3.2.2. Directly applied internal insulation An insulation board with a built in vapour control layer will stop moist internal air condensing on the cold stone behind the insulation. If stonework is uneven for instance after the removal of original plaster, the wall should be re-rendered to provide an even surface before fixing the boards. If window reveals are left uninsulated condensation may form on the cold surfaces. In order to prevent this happening insulation should be returned into reveal areas ideally using insulation with a U-value of at least 0.34 W/(m2K). Window frame thickness may necessitate reduced insulation depth and it should be ensured that the insulation does not block window trickle vents (Energy Saving Trust 2006).
3.2.3. Internal Insulation with Studwork This method of internal insulation is mostly used where internal insulation has been specified for a wall that has previously suffered from damp. It allows for the creation of a cavity between the internal wall surface and the insulation. Studwork is an effective solution in a scenario where the wall is bowed or uneven and space is not at a premium. Studwork systems using either steel or timber are available. Steel systems with thermally broken sections will give improved performance and in 14
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situations where timber is used it should be treated with an appropriate preservative. A damp proof membrane should be placed between timber and internal wall surface (Energy Saving Trust 2006).
3.2.4. Physical Adaptation of the Building Great care must be taken when designing and installing insulation at critical details in order to avoid cold bridging, particularly at reveals of windows and doors. It is more often than not, necessary to relocate services and make adjustments to skirting boards and architraves. Construction of an independent inner leaf to an existing wall will require the need for ventilation to the cavity created. A vent will allow air movement through the outer wall. This vent should be specifically designed to allow full air flow through cavity without any dead spots. It is pointless to ventilate to the inside as the air movement will just bypass the insulation and render it ineffective. High performance internal insulation will significantly alter room sizes because of its thickness to the extent that the room may not be used for same use as it had originally (English Heritage Feb 2010).
3.2.5. Changes in Appearance and Character of a Building Internal insulation will reduce the floor area of internal rooms and spaces, thus altering overall proportions. Valuable internal details such as plaster cornices, skirting and door architraves can be significantly affected and inevitably end up either concealed or disturbed to accommodate insulation. For all listed buildings, consent from planning authorities is required for any internal alterations that may affect the appearance or character of the building; this applies to both listed buildings in the UK and Ireland. In many cases this may simply make the installation of internal insulation unacceptable (English Heritage Feb 2010).
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3.2.6. Changes in Moisture Movement within Wall A useful rule of thumb is for all layers of insulated wall to become progressively more permeable from interior to exterior. To protect internal insulation from condensation occurring within its thickness it is generally necessary to separate it effectively from the warm moisture bearing air of the building’s interior. This will either require impermeable closed-cell foam insulation or an effective vapour control layer. This means that it is impossible to allow internally installed insulation to ‘breath’ or transpire moisture in the manner that traditionally constructed historic buildings always have done. This introduction of performance and qualities more appropriate to modern buildings removes any possibility of the external wall playing its normal part in the moderation of the internal environment by buffering moisture levels within the internal environment. In addition, vapour control, whilst theoretically entirely desirable is in reality notoriously difficult to achieve. Vapour barriers or more accurately ‘checks’ or ‘control layers’ are usually applied using a sheet of polythene to the insulation internally but behind the new finish. These sheets are normally very fragile and can easily be broken by building users nailing through walls or modifying electrical fittings, etc. They can also be broken during the construction process itself. All penetrations will allow moisture vapour through, which will condense either within or adjacent to the insulation causing rot and decay in a hidden location. Closed-cell foams are inherently vapour-impermeable but can be vulnerable at the joints. Both forms of vapour control are vulnerable at the perimeter, particularly in a traditional permeable structure where moisture can by-pass the physical vapour barrier through adjoining walls and floors. However, many of these problems can usefully be overcome. By creating a separate insulated inner stud wall with a ventilated cavity between it and the original external wall as the ventilation will carry away much of the moisture which tends to by-pass the vapour check. This will, however, be at the expense of the loss of internal space, and the need to introduce the external ventilation (English Heritage Feb 2010). Unlined masonry walls benefit from interior heat that keeps them dry. When the walls are lined moisture ingress from the exterior and low external temperatures may result in a problematic build-up of moisture within the original building fabric. There is also a 16
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possibility that condensation may occur between the insulation and the wall fabric resulting in further moisture build up. In order for moisture in the walls to dry out any new lining should be as breathable as the wall itself. Even inappropriate paints can affect the breathability of the wall (Dept. Of Environment Heritage and Local Government 2010).
3.2.7- Materials Almost any insulation material available can be used internally subject to proper control of vapour and careful isolation from sources of dampness. The full range of possible internal finishes can also be applied, either to copy the original or to introduce a new design (English Heritage Feb 2010). If non-breathing material is applied to old porous walls it will affect its ability to breathe and regulate moisture thus air levels are compromised. This could cause damp and structural damage where moisture is trapped inside the wall itself. As such, insulation material and the installation method are critical for improving the thermal efficiency of walls. Insulating material should be breathable and compatible with the other wall materials. Installation should be thorough to avoid cold bridging at junctions (Changeworks 2008). In all cases, however, it is vital to understand the likely effects of proposals at the design stage in order to avoid damage to both new and valuable historic building fabric.
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4.
Natural Insulation
4.1.
General
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Natural insulation covers a variety of insulation products that are derived from natural products such as wood fibre, cellulose, wool, hemp, cotton and flax. When used appropriately, natural insulations can deliver thermal and acoustic levels that are comparable with man-made insulations, while at the same time delivering a lower or potentially negative carbon footprint with fewer health issues during installation. Natural insulations can assist in regulating relative humidity and can provide a vapour permeable system. This multi-functionality should be taken into account when specifying natural insulations in order to ensure maximum value and benefits (Sutton and Black 2011). Natural insulation is typically made to form rigid boards or semi-rigid rolls or loose insulation materials for a wide range of uses in construction. The processes to making the finished products differ but most result in a fibrous material of varying stiffness, dependent on use. In most cases natural insulations have to be treated with a fire retardant and also non-toxic salts are usually added as a solution to ensure good dispersal. Natural insulations offer a vapour-permeable construction layer and if installed effectively can form part of a vapour-permeable wall, roof or floor system. Vapourpermeable systems offer significant benefits in terms of the robustness of the material together with indoor air quality. These types of systems can reduce the risk of moisture build-up as unplanned moisture ingress into external fabric can occur due to rain penetration or large air leakage. It is also important to realise that breathability is a function not only attributed to vapourpermeability but also to hygroscopicity and capillarity. With different materials these attributes may vary. Mineral wool for example has good vapour-permeability but poor hygroscopic and capillary qualities. Natural fibre insulations in general have very good hygroscopic qualities but variable capillary qualities and are all vapour open (Sutton and Black 2011). The introduction of the BER’s have meant there is more stringent requirements for higher levels of quality insulation and in turn this has led to a significant influx of a vast array of alternative insulation materials. Characteristics which once were supplementary such as 18
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living health, durability and comfort are now seen as just as critical as thermal performance. This is mainly due to the slowing market which has meant that consumers have more time to research the products they are buying. It is for this reason that natural insulations have moved from the fringe to the mainstream in Irish homes. From a sustainability and ecological standpoint, natural insulation such as hemp or woodfibre is second to none. Not only do they reduce CO2 in buildings they also absorb CO2 while being harvested. This is a major factor when one considers the high levels of CO2 emitted in the production of man-made insulations. When energy efficiency is such a major aspect of any building retrofit, one cannot underestimate the contribution of natural insulations. Buildings that are energy efficient, durable, healthy, ecological and sustainable should be designed or retrofitted with some form of natural insulation. The benefits are not only in the money that is saved but also in the environment we live (Niall Crosson 2010).
4.2.
Products
The following section will describe some of the different products available on the market to insulate a building internally. As most of these products are very unique and perform in particular ways it is difficult to describe them generically so it is better to describe each product individually. Edenbloc 35 ‘EdenBloc35’ is a product produced by a company called Second Nature which is based in the UK. ‘Edenbloc35’ is a natural, low density ridged insulation that can be used in many internal situations including wall lining, under rafters, between rafters and timber studs to provide a high level of thermal insulation. The boards can be fixed back to wall reducing the complexity of the structure. ‘Edenbloc35’ is capable of locking up nearly twice its own weight in CO2 which contribute to its low carbon footprint. The product’s patented technology combines excellent thermal performance with the breathability of natural fibres, bridging the gap between man-made insulation foams and other natural fibre insulation materials. The materials 19
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breathability ensures it acts in sympathy with the building envelope which makes it a very suitable choice for a breathable system. ‘Edenbloc35’ has a thermal conductivity of 0.036 W/(m2K) and the ability to eliminate thermal bridging as it is installed as a continuous sheet of insulation. This ability to combat thermal bridging improves insulation performance by up to 30%. The product is made from 60% recycled content and contains no synthetic binders, substantially reducing environmental impact and the need to rely on fossil derived materials (Second Nature Uk Ltd. 2010a).
Thermafleece Wool Insulation ‘Thermafleece’ is a wool based insulation roll. It is made up off sheep’s wool, recycled polyester and polyester binder with a high recycled content. ‘Thermafleece’ produce several different types of wool insulation; Original, EcoRoll, TF35 and Hemp, which all have their own unique qualities but also, share the same features. ‘Thermafleece’ products have good hygroscopic qualities which mean they can absorb and desorb water vapour without compromising its thermal efficiency. As wool is one of its main materials it can generate heat when it absorbs moisture from the air. When the air is saturated with water vapour, wool can absorb 40% of its dry weight in moisture, producing 960 kilojoules of heat energy for every kilogram of dry wool. This warmth is not noticeable inside the building but it acts to prevent condensation in construction cavities by maintaining the temperature above the dew-point in damp conditions. These products perform well as far as energy efficiency is concerned. They use 14% of the embodied energy that is used to manufacture glass fibre insulation, therefore paying back its manufacturing energy cost seven times faster than glass fibre insulations. ‘Thermafleece’ has a thermal conductivity of 0.039 W/(m2K) and when properly installed, it will retain its low density and thermal performance with a life expectancy similar to that of the construction in which it is installed. At the end of their useful life ‘Thermafleece’ products can be recycled for other environmentally friendly applications (Second Nature Uk Ltd. 2010b).
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Calsitherm Climate Board ‘Calsitherm Climate Board’ is an insulation board made for internal lining of walls and is manufactured in Germany. It is made from calcium silicate, a micro porous mineral building material with effective insulating properties which is highly diffusion open. The nature of the material and the properties of the board ensure a comfortable living environment through its ability to regulate humidity. The high PH and molecular structure of the material means that mould growth is inhibited. The board is used to insulate the internal surface of existing external masonry walls and window reveals. Insulating internally ensures that the existing external façade remains intact. This may be particularly relevant in brick and stone of listed and heritage buildings. ‘Calsitherm Climate Board’ is highly capillary active, which means that it can absorb condensed water rapidly at the interface between the wall and the board. It stores moisture within its structure and then allows it to harmlessly disperse into the living space at a later stage helping to maintain a constant relative humidity and ambient indoor climate. The board is therefore particularly relevant for public buildings that might be subject to an increase in population over a short period of time such as museums, churches and schools (Ecological Building Systems Ltd. 2012).
Figure 3 Diagram describing how Calsitherm system works
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Pavadentro ‘Pavadentro’ is a wood fibre board that is especially designed for internal insulation of exterior walls on old and historic buildings. The board reduces the formation of condensation in the existing construction to a minimum and creates a comfortable living environment. ‘Pavadentro’ is very ecological and has excellent capillary and hygrodcopic properties which prevent condensation formation and degrading of the building fabric. In addition it has a specially designed integrated mineral function layer that provides effective moisture control as it can balance humidity levels by buffering water vapour and releasing moisture back into the room to maintain a steady equilibrium. As the board is made from waste soft wood, a natural material it is naturally breathable (Natural Building Technologies Ltd. 2010).
Figure 4 Diagram showing how the Pavadentro system works
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5.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
U-Values and the BER’s
5.1 U-Values The rate at which heat is transferred through the external envelope of a building is expressed as a U-value. Heat always flows from a warm area into a cold area and each material component of the external envelope of a building transfers heat at different rates. The slower a material transfers heat, the better it is as an insulator. Low U-values are given to materials that transfer heat slowly and are therefore good insulators; thus lower U-values are better. For any given construction, independent of U-value, heat loss is directly related to the temperature difference between the exterior and interior, and, to a lesser degree, the colour and texture of the external walls. Moisture reduces any material’s ability to insulate as the conductivity of the material increases when damp and with it the U-value. Even moderate changes in dampness can significantly increase an element’s U-value thus reducing its insulating properties. Common causes of moisture ingress include damp penetration in walls due to defective or removed render, leaking gutters and poorly fitting windows frames. It is therefore important to ensure that buildings are well maintained and weather-proofed to achieve low U-values (Dept. Of Environment Heritage and Local Government 2010). 5.1.1. U-Value Calculation Method The U-values of building elements are estimated as part of any new build construction or renovation of an existing building by using software programs to show compliance with the U-value requirements of building standards prior to any construction works commencing. Such U-value calculations can then be used as part of a thermal assessment of a traditional building, for example, to aid in the choice of retrofit options (Dr. Paul Baker 2011). 5.1.2. Builddesk Software ‘Builddesk’ is a U-value calculating software package widely used throughout the UK and Irish building industry. ‘Builddesk’ calculations are based on the standards set out in the document BR 443 ‘Convention for U-value calculations’ which is published by BRE Scotland. As a market leader with a robust methodology and good usability ‘Builddesk’ is 23
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an appropriate choice of software for carrying out U-value calculations (Dr. Paul Baker 2011).
5.1.3. Assumptions for U-value Calculations The main assumptions made in order to model the build-ups used for any calculations, allowing for the restrictions in the program’s database are outlined as follows. The ‘Builddesk’ database provides only two options for stone types (sandstone and granite). The software has the ability to calculate the effect of mortar joints in brick and block constructions using the joint thickness and brick or block dimensions. A rubble wall is somewhat different since the wall is not a uniform construction with regular mortar joints. If the proportions of the constituents of the wall (stone, mortar and voids) are known or assumed from prior knowledge, the wall can be modeled as a multilayer build-up. For example, the image below represents a rubble wall with 60% stone and 40% mortar which can be modeled as two layers representing the correct proportions of the materials. For calculation purposes a ratio of 60/40 is considered to be realistic with an upper limit of 100% stone assumed for the worst case (Dr. Paul Baker 2011).
Figure 5 Traditional solid wall construction: left figure shows a schematic diagram of a rubbe wall construction with 40% mortar; and the right figure shows its representation as two laters for modeling
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5.2. Building Energy Rating (BER) and Traditional Buildings The European Directive on the Energy Performance of Buildings promotes energy efficiency in all buildings within the European Union. One of its requirements is that all new and existing buildings within the EU have an energy performance certificate. The implementation of performance certificates in Ireland is managed by the Sustainable Energy Authority of Ireland (SEAI) and takes the form of Building Energy Ratings (BER) for all building types. Ratings are calculated by the Domestic Energy Assessment Procedure (DEAP) for dwellings and by the Non-domestic Energy Assessment Procedure (NEAP) for other building types. Public buildings greater than 1000m2 are also required to display energy certificates. BER certificates are now required for all new buildings and, in the case of existing buildings that are undergoing transaction, whether lease or sale. Buildings protected under the National Monuments Acts, protected structures and proposed protected structures are exempt from the requirements to have a BER. All other traditionally built buildings are required to have a BER certificate when let or sold. There is no requirement that a building achieve a particular rating. The BER assesses the energy performance of the building, allowing potential buyers and tenants to take energy performance into consideration in their decision to purchase or rent a property. The energy rating displays both the energy requirement of the building in terms of ‘primary energy’ and the resulting carbon dioxide emissions. Primary energy includes delivered energy plus an allowance for the energy ‘overhead’ incurred in extracting, processing and transporting a fuel or other energy carrier to the building. The objective of BER is to provide an energy rating for buildings, expressed in a familiar form similar to that used for energy-rated domestic appliances such as fridges. The rating is based on a standard system of appraisal which allows all properties to be compared regardless of how they are used or occupied. In the assessment methodology the size and shape of a building are taken into account and its floor area determines the number of occupants that are assumed. The rating is based on a standardised heating schedule of a typical household, assuming two hours heating in the morning and six in the evening. A building’s BER does not take into account its location within the country, whether in the colder north or warmer south but it does consider orientation relative to the sun. It is also important to bear in mind that it does not take into account an individual household’s 25
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energy usage but assumes a standardised usage. At present the standard calculation for older buildings relies on default values for heat loss calculations. These defaults are conservative and at times may poorly represent an older building’s ability to retain heat. For example, there is only one figure for all types of stone, whereas in reality different stone types lose heat at different rates. Embodied energy is currently not accounted for in the BER system. This is an issue that requires more research in order that the characteristics of historic buildings in energy terms may be fully appreciated and recognised. On completion of a BER calculation for an existing building the assessment software generates a list of recommendations for upgrading the building in the form of an advisory report. These recommendations have been generally designed for existing buildings of modern construction rather than traditionally built buildings. (Dept. Of Environment Heritage and Local Government 2010). As stated above a BER certificate is not requirement for protected structures. However, even where a building is exempt from the need for a BER assessment some owners may nonetheless wish to up-grade the energy efficiency of their property and use the BER system as a guideline. While this is welcome, interventions that may be appropriate to a building of modern construction methods and materials could have unintended harmful consequences for historic and traditional buildings, and the health of their occupants by promoting condensation and subsequent mould growth. Where owners of historic buildings are considering changes to improve the efficiency of their properties they should consult first with their County Council’s Conservation Officer and planning permission may be required for certain inventions to protected structures.
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Figure 6 Example of a BER Certificate
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6.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Interview: Niall Crosson, Technical Engineer, Ecological Building Systems
The following chapter documents the findings gathered from a structured interview that was carried out by email. A copy of the questionnaire is included in the appendices.
6.1.
Mr. Niall Crosson- Background
Mr. Niall Crosson is a Senior Technical Engineer with Ecological Building Systems. He achieved a 1st class honours degree in Manufacturing Technology from GMIT. He then went on to complete a Masters in Engineering Science from NUIG. He has 10 years’ experience working as a Senior Technical Engineer with Ecological Building Systems. Mr. Crosson can provide extensive guidance in the area of hydrothermal analysis of building components using both the knowledge he has built up over the last 14 years and with Builddesk and WUFI dynamic modeling tools which he has been using for over 6 years. He has knowledge in relation to airtightness and thermal insulation of various forms with an emphasis on energy conservation and building healthy, comfortable living spaces. Mr. Crosson also has an in depth knowledge of a range of natural insulation products ranging from wood fibre, hemp, paper and sheep wool. Mr. Crosson gives presentations to various forums and is actively involved with the AECB, EASCA, Passive Haus Trust in the UK, and the Irish Green Building Council as well as other ecological and low energy building groups.
6.2.
Ecological Building Systems- Background
The parent company of Ecological Building Systems is MacCann & Byrne who were established in 1906 and are still to this day based in County Meath. MacCann & Byrne are importers, manufacturers and distributors of quality timber and building products. They have built their philosophy around sourcing and delivering only the best products available to the Irish market.
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Since 2000, with the dawn of ecologically conscious building, MacCann & Byrne have dedicated themselves to the development of the sustainable building industry. After spending a lot of time in Europe they recognised that their European counterparts were far more advanced when it came to the understanding and constructing of sustainable buildings. Sourcing only the highest quality sustainable building products for the Irish market, MacCann & Byrne developed a separate part of their group dedicated entirely to the concept of ecological building. Ecological Building Systems is now at the forefront for sustainable building in Ireland, supporting and supplying the market with both the technical know-how and quality tried and tested products for the sustainable building industry.
6.3.
Interview Findings
Retrofitting our Traditional Buildings Mr. Crosson feels it is essential to retrofit traditionally built buildings in Ireland to both reduce our carbon footprint, but to also ensure that these buildings are habitable in the future. An interesting point which Mr. Crosson made was that our traditionally built buildings offer most potential as far as retrofitting is concerned as they are so poorly insulated in the first instance.
Importance of BER’s and Part L On the subject of BER ratings and Part L of the building regulations, Mr. Crosson is of the opinion that traditional buildings including protected structures can be used as a guide but that a protected structure should not have to meet the criteria set out in these guidelines, which is the case currently. Such buildings may suffer long term damage if they are required to meet these standards. Mr. Crosson feels there is no silver bullet solution when dealing with our traditional buildings and that each case should be considered individually.
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Breathabilty In relation to breathability and its importance in our traditional buildings, Mr. Crosson stated that it is an absolute perquisite to attain a durable thermal solution to protect these buildings against long term degradation, and to protect the homeowner against long term internal air quality issues and financial losses. Mr. Crosson was of the opinion that traditional breathable buildings do have their advantages over modern impermeable buildings as impermeable build materials are not compatible with diffusion open wall structures and they would greatly reduce their drying potential in the event of unforeseen moisture penetration. Cost Effectiveness Cost Effectiveness was another issue raised in the questionnaire, and how sometimes with the level of detailing that is needed that external or internal insulation just is not a viable option. Mr. Crosson stated that this issue would be very project specific and dependent on the existing situation. If a building is extremely poorly insulated external insulation is always the optimum approach but not always possible and if this is the case internal insulation should only then be considered.
Achieving an A-Rating Mr. Crosson was asked if he thought it was a realistic target to aim for an A-rated wall with the type of wall that exists at Kilkishen, a 700mm limestone rubble fill wall. Mr. Crosson felt there were a few factors involved in addressing this, such as the insulation properties, would it be sustainable in the longer term for the structure and how much would it impact on the interior space. If the walls are insulated inappropriately it can lead to long term issues. Increased airtightness should not be considered without controlled ventilation. Mr. Crosson said that it is central to any low energy project to focus on the fabric first. While the walls could be upgraded to help the building achieve an A-rating, a lot of renewables would have to be introduced in other parts of the building also.
Possible options for Limestone Rubble Fill Walls Mr. Crosson was asked about insulating limestone rubble fill walls for a protected structure where external insulation would not be allowed. It was stressed that driving rain 30
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should be addressed by plastering the wall with lime or treating the wall externally by repointing damaged mortar. Mr. Crosson stated that if a ventilated cavity was not attainable in this type of wall construction then a cavity should not be used at all as an unventilated cavity would just exacerbate the condensation issue. One solution would be to level the wall with a lime based plaster and bond a capillary active diffusion open insulation such as Calsitherm, or bonding hygroscopic diffusion open woodfibre insulation such as GUTEX Thermoroom. Another alternative would be to apply a stud partition which is thermally broken to the wall and insulated with a natural insulation and sealed air tightly with a humidity variable membrane, an example of this type of product would be Pro-Clima INTELLO PLUS.
Software Builddesk and WUFI are the two types of software that Mr. Crosson uses in practice to calculate U-values and condensation assessments.
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7.
Case Study:
7.1.
Building Background
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Kilkishen Church
Kilkishen Church is an old protestant Church of Ireland located in south-east Co. Clare (refer to Appendices for site location map). The church was built in 1811 which was funded by an 800 pound grant from the Board of First Fruits who were a government body at the time. The aim of these grants was to build and repair ecclesiastical buildings to ensure that every parish had a church within walking distance. There was a bell tower added in 1834 and the church as a whole can be described as a two bay single-cell church and its orientation is approximately at east-west. There is a raised altar at the top of the nave and under this altar there is a burial crypt which can only be accessed externally. The church’s last service was in 1964 and since then it has stood unused.
Kilkishen Church in its current condition 7.2.
Walls Surveyed
The existing walls at Kilkishen are mainly constructed of limestone with cut limestone on the exterior leaf which was sourced locally in Killaloo quarry and limestone rubble fill to the interior. There is evidence of brick used also and this can be seen internally under window cills. The purpose of the use of the brick was probably to level off the wall horizontally to cater for the tapered plastered cill above the brick. Externally the walls are made from cut stone with staggered joints. The external envelope of the building has suffered some deterioration this is largely due to extensive ivy growth throughout. The ivy has dislocated stones mainly on the buttresses that are 32
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located on the four corners of the main structure. On the day of site visit the ivy was already cut and left attached to the wall, so careful removal will be possible. A number of cracks are also visible along the bedding joints in the stone work which seems to be a direct consequence of the ivy infestation and also possible freeze - thaw action. Internally the walls have two different finishes. Along longest sides of the nave the walls are finished in lime plaster from the cill up to where the wall meets the roof. Below cill level the limestone is exposed, the reason for this is that there was more than likely timber paneling from cill level to floor level and over the years in which the building was unused and vandalized this timber was destroyed. Along the other two walls, the gable walls, there was a strange method of drylining used. It consisted of battens made from mortar fixed to the wall, then a layer of slates which were nailed to wall over battens creating a cavity and finally a render over the slates which was more than likely lime based. Over the years all the lime render and slates have fallen down but the mortar battens and some nails that held the slates are still visible however. (refer to Appendices for picture survey of existing walls)
Figure 7 Plan of Kilkishen Church
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7.3.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Legislation Protecting Kilkishen Church
Kilkishen Church is a registered protected structure. In recent years the community of Kilkishen has sought to redevelop the site and change it into a cultural centre. This project has been granted permission by the Clare County Council, but as part of this a conservation declaration had to be written up. In this declaration which was compiled by the Clare County Council conservation officer, Mr. Dick Cronin, it states what can and cannot be done to the building. No changes may be made to walls externally apart from the removal of ivy growth and any re-pointing work that needs to be undertaken. Inside there is a bit more scope for change as the existing plaster is allowed to be removed if needs be and internal drylining or insulation system installed. There is also five windows in the church, a feature window above the altar and four narrow leaded windows along the sides of the nave, two on each side. The feature window above the altar must be restored to its original state or as close to its original state as possible, while the narrow windows along the side of the nave may be removed and replaced with new timber windows if desired. (refer to Appendices for planning and conservation report from Clare County Council)
7.4.
Description of Data Collected
The site survey consisted of a semi-structured interview with the Chairman of the Kilkishen Church Restoration Project, Mike Hogan. This interview gave information on the history of the building, the materials used, and what could and could not be changed to the building in the redevelopment. On site the overall wall lengths and heights were obtained using measuring tape. As there is a planned redevelopment on course for the church, plans and sections of the church were made available from Stanford Architects Ltd., who were in charge of the redevelopment. Rubble filled solid stone walls are difficult to draw up accurately, however a section was drawn up using the computer-aided design program ‘AutoCAD’. Also drawn up in 34
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AutoCAD are possible retrofit measures that could be added to the wall to improve its thermal and energy efficiency. A representation of the wall was assessed for thermal performance in current conditions and with possible upgrade measures. The program used for thermal analysis was ‘Builddesk 3.4’. (refer to Appendices for architect’s drawings)
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8.
GALWAY-MAYO INSTITUTE OF TECHNOLOGY
Analysis of Thermal Retrofit Measures to Traditional Solid Stone Walls
The following chapter is an analysis of the performance, effectiveness and viability of the different wall options available to thermally upgrade their efficiency. Specific recommendations and conclusions relating to the case study at Kilkishen Church. Conclusions are reached on each retrofit measure and are based on information from secondary literature, case study at Kilkishen Church and the interview with Mr. Crosson of Ecological Building Systems.
8.1. Analysis of Existing Walls at Kilishen Before any retrofit methods or materials were investigated, an analysis of the existing walls at Kilkishen had to be carried out. The main aim of this analysis was to get a current U-value for the wall. This analysis was carried out using the Builddesk 3.4 software. The dimensions of the church internally are 12.25m x 6.17m, the height of the walls to eaves level is approximately 4m and height at the gables to the underside of roof at ridge is approximately 7.9m. The total surface area of the internal walls is approximately 165M² and the floor area of the church is 75m². Putting a traditional limestone rubble fill wall through Builddesk,, or any kind of analyzing software for that matter, raises difficulties as the thickness of rubble and limestone and the amount of mortar vary so much. As a general rule of thumb a ratio of 60:40 is used, 60 for limestone and 40 for mortar. Using this method a 700mm wall was entered into Builddesk and the U-value returned was 1.40 W/(m²K). There can be big differences between values obtained from software and in-situ values, but during research there was evidence of similar walls analyzed using the in-situ method and values were very similar. (see Appendices for examples of walls analysed using in situ method)
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8.2.
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Analysis of Proposed Wall Solutions
All U-value calculations were obtained using the Builddesk 3.4 software and all Builddesk output pages will be included in the Appendices. All pricing was gathered from both Ecological Buildings Systems Ltd. and Ty-Mawr Ltd. 8.2.1. Proposed Wall 01-
Calsitherm Climate Board
Figure 8 Section through existing wall with Calsitherm system
The Calsitherm system as explained in the previously is made especially for this kind of scenario, for the use on historic solid stone masonry walls. The system is made up of several different layers as shown in the diagram above. This system will add approximately 66mm onto the internal side of the existing wall. With the introduction of this system it will result in a floor area of approximately 73m 2, which is 2m2 less than the current floor area of 75m2. The Calsitherm system will reduce the U-value of the wall from its original value of 1.40 W/(m²K) to 0.55 W/(m2K), this is an improvement of just over 60%. Calsitherm will cost approximately €60 per m2, which means it would cost approximately €9,900 to insulate the existing walls at Kilkishen. It should also be noted that along with the standard 50mm Calsitherm board, a tapered soffit board especially designed for use in historic window reveals is also available. 37
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8.2.2. Proposed Wall 02-
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Edenbloc 35
Figure 9 Section through existing wall with Edenbloc35 system
Edenbloc35 as explained in the previously is a natural fibre insulation which is made for use on the internal side of existing rubble walls. Along with the Edenbloc35 sheet there are also some other components which must be used in conjunction with the system such as a breather membrane between the wall and the insulation and a low emissivity vapour control layer called the Eden LEC Xtra. These two layers are vital for the system to work effectively. In the diagram above which shows all layers of the system, a 100mm Edenbloc35 sheet was used. It must be noted that these sheets are available in thicknesses of 50mm, 60mm and 75mm. Using the 100mm sheet along with the timber battens and a wall finish the system will add approximately 145mm onto the inside of the wall. This addition to the walls internally will result in a finished floor area in Kilkishen of 70m 2, a loss of 5m2. With the use of the 100mm Edenbloc35 sheet, the system will bring the existing walls at Kilkishen from their current 1.40 W/(m2K) value down to 0.24 W/(m2K). This is an 82% improvement in the thermal efficiency of the wall. The Edenbloc35 system will work out at approximately â‚Ź45 per m2 which will cost a total of â‚Ź7,425 to insulate the existing walls at Kilkishen.
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8.2.3. Proposed Wall 03-
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Thermafleece EcoRoll
Figure 10 Section through existing wall with EcoRoll system
The Thermafleece system is a wool based internal insulation system. Thermafleece produce several different products all consisting of sheep’s wool. For this proposal their EcoRoll product was used. Similar to the Edenbloc system, it also requires a breather membrane layer between the insulation and the existing wall and Thermafleece also specify the use of Eden’s LEC Xtra Low emissisvity membrane and vapour control layer. For this proposal the 140mm EcoRoll was specified and the total depth of the system will be approximately 200mm. This will result in a finished floor area in the church of 67m 2, a loss of 8m2 when compared to its original size. The Thermafleece EcoRoll system shown in the diagram above will bring the existing Uvalue of 1.40 W/(m2K) down to a 0.21 W(m2K) rating, which is a 85% improvement in thermal performance. The EcoRoll works out at a very low price of €12 per m2, meaning it would cost €1,980 to insulate the existing walls at Kilkishen Church.
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8.2.4. Proposed Wall 03-
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Pavadentro
Figure 11 Section through existing wall with Pavadentro system
Pavadentro is a wood fibre board that is made for use on the internal side of existing solid stone walls. In the above diagram 100mm Pavadentro was used. When the adhesive plaster and lime plaster finish are added the system will be 120mm altogether. Using this system will result in a finished floor area at Kilkishen of 71m2, 4m2 less than the original size. Pavadentro boards will reduce the U-value of the wall from 1.40 W/(m2K) to 0.29 W/(m2K), which is a 79% improvement to the existing walls. The boards will cost approximately â‚Ź48 per m2 which gives a total cost of â‚Ź7,900 to insulate the walls at Kilkishen using this product.
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System Thickness (mm) U-Value (W/(m2K)) Price (â‚Ź per m2) BER Rating *
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Calsitherm 66 0.55 60.00 G
Edenbloc35 145 0.24 45.00 B2
Pavadentro 120 0.29 48.00 C1
EcoRoll 200 0.21 12.00 A3
*The ratings given in the table above are only guideline ratings. The Sustainable Energy Authority of Ireland who governs the BER’s does not issue individual ratings for specific building elements. The U-value for other elements such as the floors and roofs must be calculated in conjunction with the wall values to gain an accurate BER.
8.3.
Comparison of Proposed Retrofits
All the proposals described previously are all viable options that could be considered when internally retrofitting existing solid stone walls. Each type of wall described must be considered on its own merits for each individual case. All aspects of the retrofit such as the U-value achieved, the space requirements, the level of detailing needed and the price must all be taken into account. For example, the space requirements of an internal retrofit, the depth of the system and how much it will affect the internal area would not be such a major issue in a building with a large internal space as opposed to a building with a small internal floor area. Looking at the four solutions side by side one could say that the EcoRoll system would be the stand out product to use as it has the lowest U-value which is roughly around an A3 rating and is by far the cheapest. One must also take into account that this adds a thickness of 200mm onto the existing wall which will have a major effect on window reveals and on the overall proportions of the building. The same can be said about the Edenbloc35 system, it would improve the thermal efficiency of the wall a considerably but the thickness of the system and difficulty of incorporating the system into the historic window reveals at Kilkishen would be very costly in a detailing sense and could end up being cost ineffective. An advantage for the Edenbloc35 and EcoRoll systems is that they are not attached to the wall using an adhesive mortar as breather membrane separates the insulation from the 41
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existing wall. This is a positive in a conservation sense as these systems are easily reversible if the case ever arouse that they needed to be removed. The Pavadentro and the Casitherm systems are applied directly to the wall using lime based adhesive mortars. In cases where the original wall finish must be maintained underneath the internal insulation it would be detrimental to use this adhesive mortar as if the system had to be removed it would be difficult and maybe even impossible to remove the mortar without damaging the original wall finish underneath. In the case of Kilkishen the original wall finish, which is a lime plaster can be removed therefore this is not a problem in this case. For the church at Kilkishen the space aspect would be one the most important aspects considering the existing internal floor area is just 75m2. For conservation purposes the buildings proportions will have to stay as close to the original as possible for the works to be granted planning permission. If the Calsitherm system was used the issue of detailing at the window reveals would not be such a major problem as its narrow depth of 66mm could be easily integrated at the reveals and also Calsitherm supply a tapered soffit board for the use on historic window reveals. For these reasons the Calsitherm system could be considered as the most appropriate method of internally insulating the solid stone walls at Kilkishen church. As part of Part L-Conservation of Fuel and Energy of the building regulations it states that the walls on a building should have a U-value of at least 0.37 W/(m2K) (Department of Environment 2008). As Kilkishen Church is a protected structure is does not have to adhere to the requirements in the building regulations. However there are many similar buildings around Ireland that are built using the same construction methods that are not registered as protected structures. If Kilkishen was put into this category the Calsitherm system would not comply with this requirement as the U-value of wall would not be good enough so therefore one of the other three options would have to be considered.
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9.
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Conclusions
To conclude this report and to refer back to the hypothesis of, ‘As a result of an effective retrofit can a traditional stone wall achieve an A-rated U-Value’. From the studies carried out in this report it has shown that an A-rating is achievable but it comes at a cost. In situations where one is obtaining very low U-values compromises have to be made. These compromises come in the form of a reduced floor area internally and the difficulty designers will come across in trying to incorporate extensive thicknesses of insulation internally into window and door reveals. An A-rating is achievable but it may not end up being very cost effective. Information on the specific U-values needed for the walls to achieve certain ratings was very vague and the only guidelines to go by were the approximate U-values set out by companies in their product brochures. Perhaps the Sustainable Energy Authority of Ireland (SEAI) could work to ensure that BER system could be altered in a way that would give the property owner or designer more information on individual parts of a building. It would also be an advantage if the BER system could be incorporated into the retrofitting of a protected structure. During the initial research for the report, and throughout the interview and case study stages the breathability of these buildings was emphasised as a major factor and as something that should be maintained. It was made clear that interrupting the breathability of the walls would cause major problems. In carrying out the report it revealed that there are methods and products available on the market than are capable of maintaining breathability while improving the walls thermal efficiency. A topic which came to the fore in this respect was natural insulation. It is clear that natural insulation has not been adopted totally by the consumer to date but has made great strides in recent years. The study revealed there are many different products on the market and that they can both compete and even better man-made insulations cost-wise and performance wise. Seeing that natural insulation has only became mainstream in recent years there was not much precedent to go by and case studies involving natural insulation retrofits on traditional buildings were difficult to find.
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Finally, on carrying out this study and particularly during the literature review of the topic it was very difficult to find literature from Irish sources or governing bodies. Practically all literature found was from UK governing bodies such as Historic Scotland and English Heritage. Even some Irish websites based on the subject of traditionally built buildings would refer to the UK for literature sources. Luckily this was not a hindrance to the study as traditional construction methods in Ireland and the UK were very similar. Nonetheless this gives an incentive to Irish governing bodies such as An Taisce and the Department of the Environment, Heritage and Local Government to invest more into investigating Ireland’s traditional building stock and what can be done to improve their energy efficiency.
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References Changeworks (2008). Energy Heritage- a Guide to Improving Energy Efficiency in Traditional and Historic Homes [Online]. Available: http://www.changeworks.org.uk/uploads/83096EnergyHeritage_online1.pdf [Accessed: 02/02/2012] Clinton Climate Initiative. (Year). Energy Efficient Building Retrofit Program. In, 2011. Greenbridge.[Online]. Available:http://www.societies.cam.ac.uk/greenbr/docs/2011-0210%20Andrew%20Joyner.pdf [Accessed: 30/01/2012] Department of Environment, H.A.L.G. (2008). Part L-Conservation of Fuel and Energy Buildings other Than Dwellings.[Online]. Available: http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLo ad,20322,en.pdf [Accessed: 01/03/2012] Department of the Environment and Local Government (2007). National Climate Strategy. In: Department of the Environment and Local Government (ed.).[Online]. Available: http://www.environ.ie/en/Publications/Environment/Atmosphere/FileDownLoad,1861,en.pdf [Accessed: 13/04/2012] Dept. Of Environment Heritage and Local Government (2010). Energy Efficiency in Traditional Buildings. In: Dept. Of Environment, H.A.L.G. (ed.).[Online]. Available: http://www.ahg.gov.ie/en/Publications/HeritagePublications/BuiltHeritagePolicyPublications/Ene rgy%20Efficiency%20in%20Traditional%20Buildings%20(2010).pdf [Accessed: 04/02/2012] Baker, Paul (2011). U•-Values and Traditional Buildings. In: Scotland, H. (ed.) Technical Paper 10 ed.[Online]. Available: http://www.historic-scotland.gov.uk/hstp102011-u-values-and-traditionalbuildings.pdf [Accessed: 27/02/2012] Ecological Building Systems Ltd. (2012). Calsitherm Climate Board-the Perfect Internal Insulation Material.[Online]. Available: http://ecologicalbuildingsystems.com/workspace/downloads/CALSITHERM-CLIMATE-BROCHUREMARCH-2012.pdf [Accessed: 14/03/2012] Energy Saving Trust (2006). Practical Refurbishment of Solid Walled Houses. [Online]. Available: http://www.kingston.gov.uk/practical_refurbishment_of_solid-walled_houses.pdf [Accessed: 02/02/2012] Energy Saving Trust (2008a). Energy Efficient Historic Homes-Case Studies.[Online]. Available: http://www.energysavingtrust.org.uk/Publications2/Housingprofessionals/Refurbishment/Energy-efficient-historic-homes-case-studies-2005-edition [Accessed: 30/01/2012]
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Energy Saving Trust (2008b). Internal Wall Insulation in Existing Housing- a Guide for Specifiers and Contractors.[Online]. Available: http://www.rebelenergy.ie/ce17.pdf [Accessed 02/02/2012] Energy Saving Trust (Feb 2010). Sustainable Refurbishment-Ce309.[Online]. Available: http://www.energysavingtrust.org.uk/Professional-resources/Existing-Housing [Accessed 30/01/2012] English Heritage (2011). Energy Efficiency and Historic Buildings-Application of Part L. [Online]. Available: http://www.english-heritage.org.uk/publications/energy-efficiency-historic-buildingspartl/ [Accessed: 30/01/2012] English Heritage (Feb 2010). Energy Efficiency in Historic Buildings-Insulating Solid Walls. [Online]. Available: http://www.english-heritage.org.uk/publications/eehb-insulating-solid-walls/ [Accessed: 30/01/2012] European Commision (2006). Energy Efficiency. Natural Building Technologies Ltd. (2010). Nbt Pavadentro- Wood Fibre Board for Internal Insulation of Existing Walls. Pavatex Ltd.,. [Online]. Available: http://www.sig.ie/imagePath/dynamic/image/NBT_Pavatex_Manual_PAVADENTRO.pdf [Accessed: 07/03/2012] Crosson, Niall (2010). Natural Insulation & Intelligent Airtightness: The Key to Healthy, Low Energy Construction. Ecological Building Systems.[Online]. Available: http://www.ecologicalbuildingsystems.com/workspace/downloads/Natural-Insulation-andAirtightness-Moving-In.pdf [Access Date: 12/02/2012] Oxford Dictionary (2001). Concise Oxford Dictionary, Tenth Edition. In: Pearsall, J. (ed.). Retrofit Boston (October 2010) 'Getting to Know Building Retrofit', Retrofit Boston. [Online]. Available: http://retrofitboston.com/?p=3 [Access Date: 16/01/2012] Second Nature Uk Ltd. (2010a). Edenbloc35-Natural Rigid Insulation. [Online]. Available: http://www.edenbloc.co.uk/[Access Date: 21/03/2012] Second Nature Uk Ltd. (2010b). Thermafleece Original-Factsheet. Second Nature UK Ltd. [Online]. Available: http://www.thermafleece.com/product/thermafleece-original [Access Date: 21/03/2012] Sustainable Energy Ireland (2009). Energy Efficiency in Ireland. [Online]. Available: http://www.seai.ie/Publications/Statistics_Publications/EPSSU_Publications/Energy_Efficiency_in _Ireland_2009/Energy_Efficiency_Report_2009.pdf [Access Date: 03/04/2012]
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Sutton, A. & Black, D. (2011). Natural Fibre Insulation-an Introduction to Low-Impact Building Materials. In: Trust, B. (ed.). BRE Trust. [Online]. Available:http://www.bre.co.uk/filelibrary/pdf/projects/low_impact_materials/IP18_11.pdf [Access Date: 05/04/2012]
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Appendices Appendix A: Interview Questionnaire for Mr. Niall Crosson, Technical Engineer at Ecological Building Systems Questionnaire to be part of 4th year dissertation
What is your background as far as third-level education, where and what have you studied?
How long has Ecological Systems been in business, how long have you been working for the company and what is your role in the company?
How important do you think it is to retrofit our historic/traditional buildings in Ireland for better energy efficiency?
Although BER ratings & Part L don’t apply to protected structures, do you feel that they can be used as a good guideline when retrofitting protected structures? (My final year project in Design Studies is an old church in Kilkishen Co.Clare, it is a registered protected structure, and I am using the walls of the church as a case study for my dissertation. The church has 700mm Limestone rubble fill walls)
Breathability is a prominent feature of traditional solid stone wall construction, do you feel maintaining this breathability is vital when retrofitting these walls?
Would you feel a properly maintained breathing wall has its advantages over a modern impermeable building?
For internal or external insulation retrofits to be effective a high level of detailing is required at perimeters and openings, this detailing can pump up design costs which raise the issue of cost effectiveness. Would you feel there is an issue of cost effectiveness with these systems?
As part of my hypothesis I want to see if I can achieve an A-rating out of the walls at the Kilkishen church. Would you feel this is a realistic target? 48
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Have you ever worked on a project where you have gained an A-rating out of a retrofit to a traditional solid stone structure?
As part of my case study, I am going to have to insulate internally, as the external limestone façade on the church cannot be changed. Would you have any advice on interstitial condensation and how to combat it effectively? (A ventilated cavity inside external wall is an option but would be very hard to achieve with this type of wall construction)
I have been using the Builddesk software for calculating U-values for my walls, would you also use this software in your work?
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Appendix B:
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Kilkishen Church-Case Study
Kilkishen Church
South Wall with slate and plaster drylining
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Site Map
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North Wall with showing plaster battens from originals drylining
East Wall Window showing arched window reveals and use of brick under cill
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West Wall showing stone exposed below cill level where paneling would have existed
West Wall showing existing lime plaster finish
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Close up on exposed stonework
Close up showing poor condition of existing lime plaster
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View of gable wall showing nails hammered into wall, nails would have held slate in place
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Site Layout
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Ground Floor Plan
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East & North Elevations
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West & South Elevations
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Appendix C: Planning & Conservation Report from Clare County Council
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Appendix D:
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Builddesk Results for Existing & Proposed Walls
Existing Wall at Kilkishen
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Proposed Wall 01-Calsitherm Climate Board
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Proposed Wall 02-Edenbloc35
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Proposed Wall 03-EcoRoll
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Proposed Wall 04-Pavadentro
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