sustainable refurbishment of historic buildings - international ...

LÓPEZ, M.; YÁÑEZ, A.; GOMES DA COSTA, S.; AVELLÀ, L., (Coord.). Actas del Congreso Internacional de Eficiencia Energética y Edificación Histórica / Proceedings of the International Conference on Energy Efficiency and Historic Buildings (Madrid, 29-30 Sep. 2014). Madrid: Fundación de Casas Históricas y Singulares y Fundación Ars Civilis, 2014. ISBN: 978-84-617-3440-5

Edited by Fundación de Casas Históricas y Singulares Fundación Ars Civilis Coordinated by Mónica López Sánchez. Fundación Ars Civilis Ana Yáñez Vega. Fundación de Casas Históricas y Singulares Sofia Gomes da Costa. Fundación de Casas Históricas y Singulares Lourdes Avellà Delgado. Fundación Ars Civilis

© Copyright 2014. Texts: the respective authors (or their employers); Proceedings: the coordinators and editors.

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

Table of contents

PRESENTACIÓN ............................................................................................................... - 11 Eficiencia energética y edificación histórica: un reto del presente..................................... - 13 Cristina Gutiérrez-Cortines y Mónica López Sánchez. Fundación Ars Civilis

Eficiencia energética y edificación histórica: un reto del futuro ........................................ - 14 Ana Yáñez Vega. Fundación de Casas Históricas y Singulares

Committees .................................................................................................................... - 15 Programme..................................................................................................................... - 16 -

Governance, management, participation and mediation..........................................- 21 SUSTAINABLE ENERGY ACTION FOR WORLD HERITAGE MANAGEMENT ............................ - 22 RONCHINI, C.; POLETTO, D.

ENERGY EFFICIENCY AND URBAN RENEWAL OF A UNESCO-LISTED HISTORICAL CENTER: THE CASE OF PORTO .......................................................................................... - 38 SANTOS, Á.; VALENÇA, P.; SEQUEIRA, J.

HISTORICAL HERITAGE: FROM ENERGY CONSUMER TO ENERGY PRODUCER. THE CASE STUDY OF THE ‘ALBERGO DEI POVERI’ OF GENOA, ITALY .................................................. - 45 FRANCO, G.; GUERRINI, M.; CARTESEGNA, M.

IMPROVING ENERGY EFFICIENCY IN HISTORIC CORNISH BUILDINGS – GRANT FUNDING, MONITORING AND GUIDANCE ........................................................................ - 61 RICHARDS, A.

ENERGY EFFICIENCY AND BUILDINGS WITH HERITAGE VALUES: REFLECTION, CONFLICTS AND SOLUTIONS ............................................................................................ - 75 GIANCOLA, E.; HERAS, M. R.

PROPUESTA METODOLÓGICA PARA LA REHABILITACIÓN SOSTENIBLE DEL PATRIMONIO CONTEXTUAL EDIFICADO. EL CASO DEL CENTRO HISTÓRICO DE LA CIUDAD DE MÉRIDA, YUCATÁN / Methodological proposal for the sustainable rehabilitation of context heritage building. The case of the historic downtown of Merida, Yucatan ............................................................................................................. - 82 MEDINA, K.; RODRÍGUEZ, A.; CERÓN, I.

More contents on http://energyheritage.wordpress.com/

-5-

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

Traditional and technological knowledge: concepts, techniques, practices, uses, materials, methodologies ........................................................................................- 99 SUSTAINABLE REFURBISHMENT OF HISTORIC BUILDINGS: RISKS, SOLUTIONS AND BEST PRACTICE.............................................................................................................. - 100 HEATH, N.

EFICIENCIA ENERGÉTICA Y VALORES PATRIMONIALES. LECCIONES DE UNA INVESTIGACIÓN Y UN SEMINARIO / Energy efficiency and heritage values. Lessons of a Research and a Seminar ............................................................................................. - 110 GONZÁLEZ MORENO-NAVARRO, J. L.

ARCHITECTURAL INTEGRATION OF PHOTOVOLTAIC SYSTEMS IN HISTORIC DISTRICTS. THE CASE STUDY OF SANTIAGO DE COMPOSTELA .......................................................... - 118 LUCCHI, E.; GAREGNANI, G.; MATURI, L.; MOSER, D.

HISTORIC BUILDING ENERGY ASSESSMENT BY MEANS OF SIMULATION TECHNIQUES ..... - 135 SOUTULLO, S.; ENRIQUEZ, R.; FERRER, J. A.; HERAS, M. R.

DESIGN OF A CONTROL SYSTEM FOR THE ENERGY CONSUMPTION IN A WALL-HEATED CHURCH: SANTA MARIA ODIGITRIA IN ROME................................................................. - 145 MANFREDI, C.; FRATERNALI, D.; ALBERICI, A.

EXEMPLARY ENERGETICAL REFURBISHMENT OF THE GERMAN ACADEMY IN ROME "VILLA MASSIMO" ........................................................................................................ - 160 ENDRES, E.; SANTUCCI, D.

SISTEMA MÓVIL INTEGRADO PARA LA REHABILITACIÓN ENERGÉTICA DE EDIFICIOS: LÁSER 3D, TERMOGRAFÍA, FOTOGRAFÍA, SENSORES AMBIENTALES Y BIM / Integrated mobile system for building energy rehabilitation: 3D laser, termography, fotography, environmental sensors and BIM .................................................................................... - 169 SÁNCHEZ VILLANUEVA, C.; FILGUEIRA LAGO, A.; ROCA BERNÁRDEZ, D.; ARMESTO GONZÁLEZ, J.; DÍAZ VILARIÑO, L.; LAGÜELA LÓPEZ, S.; RODRÍGUEZ VIJANDA, M.; NÚÑEZ SUÁREZ, J.; MARTÍNEZ GÓMEZ, R.

CONSECUENCIAS CONSTRUCTIVAS Y ENERGÉTICAS DE UNA MALA PRÁCTICA. ARQUITECTURAS DESOLLADAS / Energy and constructive consequences of a bad practice. Skinned architectures ..................................................................................... - 186 DE LUXÁN GARCÍA DE DIEGO, M.; GÓMEZ MUÑOZ, G.; BARBERO BARRERA, M.; ROMÁN LÓPEZ, E.

EL BIENESTAR TÉRMICO MÁS ALLÁ DE LAS EXIGENCIAS NORMATIVAS. DOS CASOS. DOS ENFOQUES / Thermal comfort beyond legislation. Two examples. Two approaches ................................................................................................................... - 201 DOTOR, A.; ONECHA, B.; GONZÁLEZ, J. L.

LA MONITORIZACIÓN Y SIMULACIÓN HIGROTÉRMICA COMO HERRAMIENTA PARA LA MEJORA DEL CONFORT, PRESERVACIÓN Y AHORRO ENERGÉTICO DE ESPACIOS PATRIMONIALES. EL CASO DE LA IGLESIA DE SAN FRANCISCO DE ASIS, MORÓN DE LA FRONTERA / Measurement and hygrothermal simulation model, a tool to enhance thermal comfort, preservation and saving energy of heritage site. Case study: the church of San Francisco of Asís in Morón de la Frontera ................................................. - 210 MUÑOZ, C.; LEÓN, A.; NAVARRO, J.

More contents on http://energyheritage.wordpress.com/

-6-

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

TERESE3: HERRAMIENTA INFORMÁTICA PARA LA EFICIENCIA ENERGÉTICA MEDIANTE LA SIMULACIÓN CALIBRADA DE EDIFICIOS / TERESE3: informatic tool for the energetic efficiency through the calibrated simulation of buildings ............................................... - 226 GRANADA, E.; EGUÍA, P.; MARTÍNEZ, R.; NÚÑEZ, J.; RODRÍGUEZ, M.

EFICIENCIA ENERGÉTICA Y ANÁLISIS TÉRMICO PARA SISTEMAS DE AIRE CENTRALIZADO: UN CASO DE ESTUDIO / Energy Efficiency and thermal analysis for centralized air heating systems: a case study ................................................................. - 238 MARTÍNEZ-GARRIDO, M. I.; GOMEZ-HERAS, M.; FORT, R.; VARAS-MURIEL, M. J.

ANALISIS ENERGETICO DEL MUSEO DE HISTORIA DE VALENCIA MEDIANTE DISTINTAS HERRAMIENTAS DE SIMULACIÓN / Energy assessment of the History Museum of Valencia using various simulation tools ......................................................................... - 249 TORT-AUSINA, I.; VIVANCOS, J.L.; MARTÍNEZ-MOLINA, A.; MENDOZA, C. M.

APROVECHAMIENTO SOLAR PASIVO EN LA RETÍCULA URBANA DE LA CIUDAD HISTÓRICA. EL CASO DE CÁDIZ / Passive solar gains in the urban grid of the historic city. The case study of Cadiz .......................................................................................... - 257 SÁNCHEZ-MONTAÑÉS, B.; RUBIO-BELLIDO, C.; PULIDO-ARCAS, J. A.

TECHNICAL SYSTEM HISTORY AND HERITAGE: A CASE STUDY OF A THERMAL POWER STATION IN ITALY ......................................................................................................... - 275 PRETELLI, M.; FABBRI, K.

ANALISIS ENERGÉTICO Y PROPUESTAS DE MEJORA DE UNA CASA EN REQUENA MEDIANTE PROGRAMAS DE SIMULACIÓN / Energy analysis and improvement proposal of a house in Requena (Spain) using simulation software ................................. - 281 TORT-AUSINA, I.; VIVANCOS, J.L.; MARTÍNEZ-MOLINA, A.; MENDOZA, C. M.

UNA REVISIÓN DE PUBLICACIONES EN EDIFICIOS DESDE EL ASPECTO ENERGÉTICO / A review of papers in buildings from the energetic perspective ......................................... - 292 TORT-AUSINA, I.; MARTÍNEZ-MOLINA, A.; VIVANCOS, J.L.

MORTEROS MIXTOS DE CAL Y CEMENTO CON CARACTERÍSTICAS TÉRMICAS Y ACÚSTICAS MEJORADAS PARA REHABILITACIÓN / Lime-cement mixture with improved thermal and acoustic characteristics for rehabilitation ................................... - 303 PALOMAR, I.; BARLUENGA, G.; PUENTES, J.

NEAR ZERO ENERGY HISTORIC BUILDING. TOOLS AND CRITERIA FOR ECOCOMPATIBLE AND ECOEFFICIENT CONSERVATION .............................................................................. - 318 BAIANI, S.

INTEGRANDO RENOVABLES EN LA CIUDAD HEREDADA: GEOTERMIA URBANA / Integrating renewable in the inherited city: urban geothermal....................................... - 329 SACRISTÁN DE MIGUEL, M. J.

ANÁLISIS Y PROPUESTAS DE MEJORA DE LA EFICIENCIA ENERGÉTICA DE UN EDIFICIO HISTÓRICO DE CARTAGENA: ANTIGUO PALACIO DEL MARQUÉS DE CASA-TILLY / Analysis and proposals for improving the energy efficiency of a historical building in Cartagena: the former Palace of the Marquis of Casa-Tilly ............................................. - 344 COLLADO ESPEJO, P. E.; MAESTRE DE SAN JUAN ESCOLAR, C.

REHABILITACIÓN ENERGÉTICA DE EDIFICIOS DE VIVIENDAS BAJO EL PLAN ESPECIAL DE PROTECCIÓN DEL PATRIMONIO URBANÍSTICO CONSTRUIDO EN DONOSTIA-SAN SEBASTIÁN / Building energy retrofit of dwellings under the special plan of urban built heritage protection in Donostia-San Sebastian ....................................................... - 357 -

More contents on http://energyheritage.wordpress.com/

-7-

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

MARTÍN, A.; MILLÁN, J. A.; HIDALGO, J. M.; IRIBAR, E.

IS TEMPERIERUNG ENERGY EFFICIENT? THE APPLICATION OF AN OLD-NEW HEATING SYSTEM TO HERITAGE BUILDINGS ................................................................................. - 366 DEL CURTO, D.; LUCIANI, A.; MANFREDI, C.; VALISI, L.

TERMOGRAFÍA INFRARROJA Y EDIFICIOS HISTÓRICOS.................................................... - 380 MELGOSA, S.

SIMULATION MODEL CALIBRATION IN THE CONTEXT OF REAL USE HISTORIC BUILDINGS .................................................................................................................... - 388 ENRÍQUEZ, R.; JIMÉNEZ, M.J.; HERAS, M.R.

THE THERMOPHYSICAL CHARACTERIZATION OF TECHNICAL ELEMENTS IN THE HISTORIC ARCHITECTURE: EXPERIENCES IN PALERMO .................................................... - 397 GENOVA, E.; FATTA, G.

ENERGY EVALUATION OF THE HVAC SYSTEM BASED ON SOLAR ENERGY AND BIOMASS OF THE CEDER RENOVATED BUILDING ............................................................ - 407 DÍAZ ANGULO, J. A.; FERRER, J. A.; HERAS, M. H.

Legal and technical regulation and historic buildings ............................................. - 419 OLD BUILDING, NEW BOILERS: THE FUTURE OF HERITAGE IN AN ERA OF ENERGY EFFICIENCY ................................................................................................................... - 420 JANS, E.; ICOMOS, M.; KOPIEVSKY, S.; AIRHA, M.

HISTORIC WINDOWS: CONSERVATION OR REPLACEMENT. WHAT'S THE MOST SUSTAINABLE INTERVENTION? LEGISLATIVE SITUATION, CASE STUDIES AND CURRENT RESEARCHES ................................................................................................................. - 432 PRACCHI, V.; RAT, N.; VERZEROLI, A.

ENERGY RETROFIT OF A HISTORIC BUILDING IN A UNESCO WORLD HERITAGE SITE: AN INTEGRATED COST OPTIMALITY AND ENVIRONMENTAL ASSESSMENT............................ - 450 TADEU, S.; RODRIGUES, C.; TADEU, A.; FREIRE, F.; SIMÕES, N.

PARQUE EDIFICADO O PATRIMONIO EDIFICADO: LA PROTECCIÓN FRENTE A LA INTERVENCIÓN ENERGÉTICA. EL CASO DEL BARRIO DE GROS DE SAN SEBASTIÁN / Built Park or Built Heritage: Protection against energy intervention. The case of Gros district of San Sebastian ................................................................................................ - 464 URANGA, E. J.; ETXEPARE, L.

SIMULTANEOUS HERITAGE COMFORT INDEX (SHCI): QUICK SCAN AIMED AT THE SIMULTANEOUS INDOOR ENVIRONMENTAL COMFORT EVALUATION FOR PEOPLE AND ARTWORKS IN HERITAGE BUILDINGS ............................................................................. - 478 LITTI, G.; FABBRI, K.; AUDENAERT, A.; BRAET, J.

PROBLEMÁTICA DE LA POSIBLE CERTIFICACIÓN ENERGÉTICA CON CE3X DEL PATRIMONIO ARQUITECTÓNICO: EL CASO DEL ALMUDÍN DE VALENCIA / Difficulties found in the possible energy certification of heritage by using the CE3X software: the case of El Almudín of Valencia ....................................................................................... - 495 CUARTERO-CASAS, E.; TORT-AUSINA, I.; MONFORT-I-SIGNES, J.; OLIVER-FAUBEL, E. I.

PROTOCOL FOR CHARACTERIZING AND OPTIMIZING THE ENERGY CONSUMPTION IN PUBLIC BUILDINGS: CASE STUDY OF POZUELO DE ALARCÓN MUNICIPALITY ................... - 506 RUBIO, A.; MACÍAS, M.; LUMBRERAS, J.

More contents on http://energyheritage.wordpress.com/

-8-

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

Promotion, training, education .............................................................................. - 513 THE WORK OF THE SUSTAINABLE TRADITIONAL BUILDINGS ALLIANCE AND AN INTRODUCTION TO THE GUIDANCE WHEEL FOR RETROFIT ............................................. - 514 MAY, N.; RYE, C.; GRIFFITHS, N.

TRAINING OF EXPERTS FOR ENERGY RETROFIT AT THE FRAUNHOFER CENTRE FOR THE ENERGY-SAVING RENOVATION OF OLD BUILDINGS AND THE PRESERVATION OF MONUMENTS AT BENEDIKTBEUERN .............................................................................. - 528 KILIAN, R.; KRUS, M.

SPECIALIZED ENERGY CONSULTANTS FOR ARCHITECTURAL HERITAGE ............................ - 535 DE BOUW, M.; DUBOIS, S.; HERINCKX, S.; VANHELLEMONT, Y.

RENERPATH: METODOLOGÍA DE REHABILITACIÓN ENERGÉTICA DE EDIFICIOS PATRIMONIALES / RENERPATH: Methodology for Energy Rehabilitation of Heritage Buildings....................................................................................................................... - 543 PERÁN, J. R. ; MARTÍN LERONES, P.; BUJEDO, L. A.; OLMEDO, D.; SAMANIEGO, J.; GAUBO, F.; FRECHOSO, F.; ZALAMA, E.; GÓMEZ-GARCÍA BERMEJO, J.; MARTÍN, D.; FRANCISCO, V.; CUNHA, F.; BAIO, A.; XAVIER, G.; DOMÍNGUEZ, P.; GETINO, R.; SÁNCHEZ, J. C.; PASTOR, E.

LEVANTAMIENTOS ARQUITECTÓNICOS EN EL MEDIO RURAL / Architectural surveys in rural areas .................................................................................................................... - 553 HIDALGO, J.M.; MILLÁN, J. A.; MARTÍN, A.; IRIBAR, E.; FLORES, I.; ZUBILLAGA, I.

AUTHORS INDEX .................................................................................................... - 567 -

-9-

More contents on http://energyheritage.wordpress.com/

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

SUSTAINABLE REFURBISHMENT OF HISTORIC BUILDINGS: RISKS, SOLUTIONS AND BEST PRACTICE HEATH, N. HEATH, N.: NDM Heath Ltd: Sustainable Energy Solutions. UK. [email protected]

ABSTRACT Nicholas Heath is Founding Director of NDM Heath Ltd, a UK-based sustainable energy consultancy specialising in the refurbishment of traditional and historic buildings. Nicholas sits on the Steering Group of the Sustainable Traditional Buildings Alliance (STBA), and is an Affiliate and Technical Panel member of the Institute of Historic Building Conservation (IHBC); he is also Associate Consultant with the Scottish sustainable development organisation Changeworks. He is the author of numerous technical guides and research papers, and has worked with clients including UNESCO, UNDP Croatia, the Scottish Government, Historic Scotland, English Heritage, the Energy Saving Trust, and many local authorities and academic institutions. Addressing energy efficiency is fast becoming one of the most pressing issues in older, traditionallyconstructed buildings, particularly with finance schemes promoting mass-scale insulation programmes. Retaining character and significance is often perceived to be at odds with achieving improved thermal efficiency, and there is much controversy around the risks and benefits of different technical solutions. These issues are all compounded when dealing with historic buildings. Upgrading historic building fabric is notoriously complex and often costly, particularly where conservation restrictions apply, and a holistic understanding is required before modern materials are applied to old structures to minimise unintended and negative consequences. However, with a meticulously detailed approach and a sound understanding, successful retrofit is possible, and examples of good practice and research can be found across Europe.

1. INTRODUCTION Any research and commentary on sustainable energy in traditional and historic buildings is both subjective and location-specific (in relation to myriad variable including climate, building fabric, energy-related issues, technical solutions, conservation priorities, finance structures, local policies and so on). The majority of this article relates to the UK, where all the previouslymentioned variables differ from those elsewhere in Europe. However, while specifics may be subject to variation the over-arching principles of sustainable refurbishment often remain valid regardless of location. It is also important to define what is meant by a ‘historic’ building. This term covers a wide and potentially limitless spectrum of building types and ages, but for the purposes of this paper it may be taken to mean older, traditionally-constructed buildings, generally with solid masonry walls. (It is also relevant to buildings both with and without formal protection, i.e. many of the principles and issues relating to protected buildings also relate to unprotected buildings of similar age and construction.)

2. HISTORIC BUILDINGS AND SUSTAINABILITY It is well understood that the ongoing use of historic buildings is inherently sustainable, in all senses (i.e. environmentally, financially and socially). However, in order to remain sustainable all things – including historic buildings – must evolve to meet the needs of today and tomorrow. In many cases conservation designation is used to prohibit or limit improvements to the energy and

More contents on https://energyheritage.wordpress.com/

- 100 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

environmental performance of historic buildings, leading to an assumption that they are ‘exempt’ from having to contribute to a sustainable built environment. And let us be clear from the outset: doing nothing is not an option. The UK Building Regulations [1] apply exemptions to listed buildings, conservation areas and scheduled monuments. Within these exemptions there are caveats: ‘The exemption applies only to the extent that compliance with the energy efficiency requirements would unacceptably alter…character or appearance’; ‘The aim should be to improve energy efficiency as far as is reasonably practicable’; and so on. However, such wording implicitly introduces ambiguity and reinforces the subjectivity referred to in the introduction. Who decides whether alterations are ‘unacceptable’? Who defines what is ‘reasonably practicable’? (In most cases it is the planning and/or conservation regulatory bodies – and this introduces another challenge for the sustainable refurbishment of historic buildings, i.e. decisions on sustainability are being made by conservation experts but not energy experts.) In the UK the planning system has dual responsibilities – to support both the protection of the historic environment and the reduction of CO2 emissions. One of the key strategic goals in sustainable refurbishment of historic buildings is to view these responsibilities as mutual rather than exclusive. It is also important to define ‘protection’, which again is subject to individual and local differences in interpretation: for example, on the micro scale protection may be inferred as preventing building alterations, while on the macro scale enabling CO2 reduction measures may protect building fabric from climate-related damage. The holistic definition of conservation must be taken as being ‘management of change’. In reality, planning decisions are subjective, and vary according to individual officers, regional policy and local interpretations of national policy. Of course there is no ‘one-size-fits-all’ approach for historic buildings, but there are common principles that may be followed in most cases. This subjective approach to decision-making can be a source of frustration to the general public, who may not have a detailed understanding of planning or conservation priorities and can view them simply as barriers to their personal building-related goals. However, it is important to understand the importance of having a planning and conservation structure in place, in order to prevent inappropriate interventions. The issue therefore returns to one of education, in both camps: the conservation experts require a greater knowledge of energy and sustainability needs, while the general public requires a deeper understanding of the importance of our built heritage. Taking this education need as a given, the main challenge then becomes this: how can we make significant improvements to the energy efficiency and environmental performance of historic buildings while retaining their character and avoiding unintended consequences?

3. TECHNICAL CHALLENGES OF REFURBISHMENT Safeguards are written into policy and guidance documents, in an effort to minimise the technical risks associated with imperfect refurbishment of traditional buildings. But how safe are they in practice? The following quotes are taken from the UK Building Regulations [2]: •

‘Work should not prejudice the character of the host building or increase the risk of long-term deterioration of the building fabric or fittings’

•

‘Particular issues relating to work in historic buildings…include…enabling the fabric of historic buildings to ‘breathe’ to control moisture and potential long-term decay problems’

More contents on https://energyheritage.wordpress.com/

- 101 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

•

MADRID 29-30 | 09 | 2014

The adoption of any particular energy efficiency measure should not involve unacceptable technical risk of…excessive condensation’

Unfortunately, examples abound of technical failures in traditional buildings caused by energyrelated refurbishment works. These mainly relate to moisture, e.g. damp, condensation, mould and in extreme cases structural damage and decay. In many cases the root cause of these physical problems is a combination of a) lack of proper understanding and assessment of traditional buildings and b) application of a mainstream approach better suited to different building types. So how can we retrofit traditional buildings ‘properly’? Doing it right means doing it safely, significantly and affordably – and in most cases, with occupants in situ. •

Safely = minimising technical risk

•

Significantly = making meaningful impacts (whether this is in terms of CO2, comfort or fuel costs)

•

Affordably = replicably

This paper focuses mainly on safe retrofit, but brief mention must be made of the other key aspects.

3.1. Significant Retrofit Retrofit must have a meaningful impact in order to be of any significance. This may relate to CO2 emissions, occupant comfort or running costs – where the impact takes place is dependent on the strategy of the individual retrofit project. It must also be recognised that addressing one area does not automatically affect another, i.e. a project may reduce CO2 emissions dramatically without benefiting occupant comfort, or vice versa; this reinforces the need for a sound education to inform a holistic approach. If we take CO2 reduction as one project strategy, how can this be addressed significantly in the historic environment? In terms of physical building upgrade measures, with a reasonable level of retrofit it may be possible to achieve c.40-50% CO2 savings in a historic building – but this is only halfway to the 80-90% we are told we must achieve in order to limit the effects of climate change. Therefore, as well as addressing a) individual buildings we must also make savings b) in the surrounding environment (e.g. through communal, area-based renewable energy schemes) and c) in the national and international infrastructure (e.g. green grids). The point here is that all areas must be addressed – i.e. historic buildings must not be excluded from the process.

3.2. Affordable retrofit It is not uncommon for deep retrofits of traditional and historic buildings to cost very large amounts, due to the added complexity, specialist materials, consultant fees and specialist installers required for historic buildings. Achieving an 80% CO2 reduction, for example, may well cost somewhere around £80,000 – i.e. £1,000 per 1% (of course there is no linear correlation). This is clearly not replicable: in England there are over 7 million solid-walled homes, and Government retrofit plans often cite costs of £5-7,000 per property, which clearly will not come close to achieving the sort of CO2 cuts needed. The challenge is to continue driving innovation and identify affordable insulation techniques that are appropriate for traditional and historic buildings, to ensure appropriate approaches are embedded into mainstream retrofit markets so that they become widely available and costs reduce, and to create longer-term funding schemes that drive the adoption of such appropriate systems.

More contents on https://energyheritage.wordpress.com/

- 102 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

3.3. Safe retrofit Retrofitting traditional and historic buildings is notoriously complex, and is still something of a niche so suitable approaches have yet to enter the mainstream in many cases. Most technical risks relate to moisture, and these include the following [3]: •

High humidity (mould, dust mites, health issues)

•

Condensation – both on surfaces and in cavities (decorative & fabric damage)

•

High moisture content in materials (rot, e.g. joist ends)

•

Frost damage (detached render, spalling brickwork)

Added to this is the cost and disruption of repairs, which could be considerable where major damage has been caused or where the issues affect many buildings (e.g. social housing schemes where hundreds of homes are insulated in a single scheme). There are many risk factors, including insulation materials & systems, ventilation, assessment methods, coverage (thermal bridging), detailing in the studio and application on site. A brief summary of these issues is outlined below – but it is important that these are fully understood and more detailed reading of the sources provided in the bibliography is recommended:

3.3.1. Materials, ventilation and assessment methods Traditional buildings are made from permeable materials, allowing moisture to enter and disperse from the building fabric. There is a generally-agreed principle among UK conservation bodies to retain this feature when insulating, which dictates the use of vapour-permeable insulation materials and systems. However, most mainstream systems are impermeable, particularly those used for wall insulation, and while these can sometimes be used effectively in traditional buildings great care and attention to detail are required to avoid moisture-related risks. Many challenges exist in increasing the uptake of permeable systems. These include a low general awareness of both the issues and the systems, a tendency to higher costs for permeable systems that are often viewed as ‘specialist’ (particularly when slim-line systems are required for discretion or space saving), the depth of materials sometimes required to achieve very low Uvalues, and acceptance by installers. When improving energy efficiency in traditional buildings it is important to address excessive ventilation and draughts, but not to over-seal buildings and trap moisture. This is often not considered sufficiently, particularly with large-scale insulation projects. Insulation changes internal building conditions (e.g. Relative humidity), particularly where impermeable systems are used. In addition, this issue becomes more important as levels of insulation increase – so with ever-more demanding energy- and CO2-saving targets, the push for more and more insulation needs to be accompanied by a proper ventilation assessment. This is complicated by formal ventilation and moisture assessment mechanisms, which on the one hand tend to under-estimate the benefits of comprehensive draught proofing, and on the other hand misrepresent the moisture risks in insulation assessments. Recent research [4] has identified key shortcomings in this area: ‘There are many uncertainties and complexities in regard to moisture risk and management, and…the importance of learning cannot be [over]stated. Learning refers not only to the

More contents on https://energyheritage.wordpress.com/

- 103 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

understanding of moisture principles, but also…of buildings, their context and the way they are used’ ‘The existing…guidance for moisture risk assessment in standards and regulations in the UK, are not sufficient, in many situations [e.g. old buildings] to deal with a proper moisture risk assessment’ The current thinking in UK conservation circles tends towards maintaining natural ventilation and moisture movement, and the use of fully vapour-permeable insulation systems to minimise the risks associated with sub-optimal ventilation.

3.3.2. Thermal bridging, detailing and application Incomplete coverage is inevitable when insulating existing buildings, particularly traditional and historic buildings where major disruption is more complex and/or not permitted. Common problem areas include floor-wall junctions, door & window surrounds, complex windows (e.g. bay windows, stone mullions and cills) and poor jointing of insulation panels. The risks of discontinuous insulation are both heat loss and condensation, and the impacts of these can be considerable. Forthcoming research by the STBA on internal wall insulation reveals major heat loss discrepancies between buildings with lots of insulation on the plane walls but none on the reveals, as compared with less insulation on plane walls but with reveals also insulated. To minimise the level of thermal bridging, meticulous attention to detail is required, both in the design studio and on site, together with monitoring of both works and installed systems to detect any issues. Unfortunately short-term funding, which often does not extend to accommodate the use of more forgiving (e.g. vapour-permeable) insulation systems, can put such time pressure on contractors and project managers that awkward details are avoided altogether, which increases the risks associated with thermal bridging. To get it right, it will take longer and it will cost more – but the implications of not adopting an appropriate strategy are potentially serious.

4. RESEARCH AND TOOLS FOR INSULATING SOLID WALLS Solid wall insulation is the big issue in the UK at present, both in terms of Government insulation drives and traditional building research. However, both internal and external options are complex and carry technical and aesthetic risks, and there are still many unknowns and many differing opinions. While internal insulation is generally felt to carry the greatest risks, in many instances external insulation – in itself risky – will not be possible for aesthetic reasons and so internal insulation is likely to be selected in many cases. Recent research [5] conducted by NDM Heath Ltd in behalf of English Heritage highlights many of the current issues surrounding external wall insulation. Often deemed to be the lowerrisk wall insulation method, this research – which analysed three large-scale projects across the North of England – found that this is often not the case. The following key findings were identified: •

The notion of external insulation as the low-risk option is not necessarily true

•

It can be hard applying external insulation comprehensively (and therefore minimising risks)

•

There is a clear and considerable gap between advice and practice

More contents on https://energyheritage.wordpress.com/

- 104 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

•

There are major knowledge gaps among both planning bodies and project leaders (and knowledge levels are dependent on individuals)

•

Funding and time pressures are a major cause of imperfect installations

•

Ventilation issues are not fully considered

•

There were numerous reports of damp from occupants across all three projects assessed (within 12-24 months of installation)

•

The majority of properties had extensive levels of thermal bridging

•

Complex areas tend to be avoided or worked around rather than addressed properly

•

Impermeable insulation systems were used throughout all projects

•

There was considerable confusion surrounding the planning system, both in terms of regional inconsistencies (i.e. permitting/demanding different approaches in neighbouring regions) and decisions promoting thermal bridging (e.g. requiring original building features to remain exposed and uninsulated)

•

Even where risks are known, projects tend to proceed regardless, due both to the pressure to act and the uncertainty of the risks

•

Despite the issues identified above, such projects can be very important in deprived areas; they were generally well-received by occupants aesthetically, thermally and financially; and without treatment some of these areas are at risk of further decay and demolition. - 105 -

Figure 1. ‘External Wall Insulation in Traditional buildings’ research report (English Heritage, 2014)

However, leading on from this project – which highlighted more risks than solutions – a very positive project was instigated by one of the case study leaders. Blackpool Council, concerned about the quality issues in recent solid wall insulation projects, commissioned NDM Heath Ltd

More contents on https://energyheritage.wordpress.com/

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

and the STBA to produce a set of tools [6] to drive higher-quality, lower-risk insulation projects in the future. These tools comprised a) a Decision Making Protocol, to allow developers to make rapid and consistent decisions, b) a Code of Conduct, to provide quality assurance for both the Council and home owners, and c) a List of Approved Suppliers for solid wall insulation. The Decision Making Protocol contains a set of key principles to be followed in all solid wall insulation projects, followed by local considerations (such as exposure, building stock and weather conditions), and then a series of flow charts designed to lead the user through all of the main considerations and direct them to the appropriate solution for any given project. The Code of Conduct contains a long list of quality requirements for installers, and allows Blackpool Council to control the systems and detailing used on projects. Contractors signing up to the Code of Conduct will be placed on a list of approved contractors.

5. CASE STUDIES AND BEST PRACTICE There is a great deal of theoretical and practical knowledge emerging in the UK on historic building retrofit. Leading institutions including the Sustainable Traditional Buildings Alliance (STBA), Historic Scotland, English Heritage, Changeworks and the Society for the Protection of Ancient Buildings (SPAB) among others have published research, field trials and monitoring of innovative solutions for traditional buildings. An increasing amount of guidance and advice publications are also available, together with online tools and training programmes to maximise dissemination and improve awareness. In the UNESCO World Heritage Site of central Edinburgh, the Scottish sustainable development organisation Changeworks has developed and led numerous high-profile, award-winning projects upgrading Georgian listed buildings with energy efficiency and renewable energy systems, running major conferences, publishing comprehensive guidance and driving policy change to facilitate such improvements on a wider scale. Together with funding and support from The City of Edinburgh Council, Edinburgh World Heritage and Historic Scotland, Changeworks has worked with Lister Housing Co-operative on the following projects: •

Energy Heritage – trialling and monitoring insulation and education measures in historic buildings, together with best practice guidance [7]

•

Renewable Heritage – installing renewable energy systems in the same buildings, together with best practice guidance [8]

•

Double Glazing in Listed Buildings – installing a wide range of bespoke double glazing systems in historic buildings, together with a comprehensive report which led to a citywide policy change [9]

In addition, Changeworks has written planning guidance for the city of Bath in England – another UNESCO World Heritage Site – on the sustainable retrofit of listed buildings [10]. They have also run a major conference on solid wall insulation and published the proceedings with the Scottish Government [11], as well as writing a number of Historic Scotland’s Technical Papers (see below). Their contribution in this field is widely recognised, and they continue to work on relevant projects including a 3-year EU tenement refurbishment project with 6 European partners [12]. Historic Scotland has led many field trials in recent years, coupled with extensive monitoring and publication of guidance and research papers. Their work provides extensive details of this work and is regularly updated. Their key resources are as follows:

More contents on https://energyheritage.wordpress.com/

- 106 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

•

Technical Papers 1-23 [13]

•

Refurbishment Case Studies 1-12 [14]

•

Short Guide 1, condensing their current thinking [15]

Figure 2. Solar thermal panels on Georgian listed buildings in Edinburgh’s UNESCO World Heritage Site, installed as part of Changeworks’ ‘Renewable Heritage’ project

Similar UK organisations have also published guidance based on field trials and extensive monitoring. English Heritage has a suite of ‘Energy Efficiency in Traditional Buildings’ advice publications [16]; the Society for the Protection of Ancient Buildings (SPAB) publishes regular update reports based on their U-value and hygrothermal testing [17]. The Sustainable Traditional Buildings Alliance (STBA) was formed in 2011, and has published a range of high-level strategic documents, highlighting some critical shortcomings in the current UK strategy to retrofitting traditional buildings. In addition they have developed a guidance wheel and knowledge which houses the majority of current research in this field. Their key outputs to date are as follows (full details are provided in the STBA’s conference paper): •

Responsible Retrofit of Traditional Buildings [18]

•

Responsible Retrofit Guidance Wheel [19] – an interactive online tool for professionals to assess risks as part of refurbishment strategies

•

Moisture Risk Assessment and Guidance [20]

•

Heat Loss from Thermal Bridging in Internal Wall Insulation of Solid Buildings [21]

In addition to the above resources, training has been developed both nationally and internationally. UNESCO has delivered repeat ‘Sustainable Energy Governance in UNESCO World Heritage Sites’ training schools in Croatia, and developed strategic principles to mainstream sustainable energy in UNESCO sites. In the UK, the Construction Industry Training Board (CITB) is currently piloting ‘Energy Efficiency in Pre-1919 Traditional Buildings’ accredited courses for site managers, with a view to developing a national training qualification in the future.

More contents on https://energyheritage.wordpress.com/

- 107 -

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

While the majority of the above guidance focuses mainly on energy efficiency, advice is also available on renewable energy in traditional and historic homes. While this is covered in Changeworks’ Renewable Heritage guide (see above) and the STBA’s Guidance Wheel (see above), a condensed overview of each of the main technologies in relation to historic buildings, together with case studies and economic assessments, is available in a recently published report by NDM Heath Ltd on behalf of Uppsala University [22], as part of the EU ‘Climate for Culture’ project [23]. This includes case studies from across Europe, ranging from small to large in scope and building type.

6. SUMMARY This paper presents a brief snapshot of current issues and work in the UK in relation to the sustainable upgrade of historic buildings. It is intended as an introduction only, and it is recommended that the references (see below) are consulted, together with the other conference papers, in order to gain a holistic understanding of the complexities of this field. There are many challenges in achieving a truly sustainable, low-risk historic building retrofit. However, this should not be a barrier to success, and with a thorough understanding and a meticulous attention to detail it is possible to refurbish such buildings successfully and minimise the risk of unintended consequences, as illustrated by the examples in this report. Lastly, it should be noted that research continues to develop, along with pilot projects, monitoring and the development of innovative technical solutions. This is a fast-changing environment, where new findings come to light regularly, and as such the content of any advice or guidance should be taken in the knowledge that it is subject to change in the future.

7. REFERENCES

- 108 -

[1]. HM Government (2010). The Building Regulations 2010: Conservation of Fuel and Power: Approved Document L1B: Conservation of Fuel and Power in Existing Dwellings (2010 edition, incorporating 2010 and 2011 amendments). UK, NBS (RIBA Enterprises Ltd.) [2]. Ibid. [3]. Sustainable Traditional Buildings Alliance (2014). Moisture Risk Assessment and Guidance (Draft). UK, Department of Energy and Climate Change. [4]. Ibid. [5]. NDM Heath Ltd. (2014). External Wall Insulation in Traditional Buildings: Case Studies of Three Largescale Projects in the North of England. UK, English Heritage. [6]. NDM Heath Ltd & STBA (2014). Decision Making Protocol for Solid Wall Insulation Projects; Code of Conduct for Solid Wall Insulation Projects. UK, Blackpool Council. [7]. Changeworks (2008). Energy Heritage – A Guide to Improving Energy Efficiency in Traditional and Historic homes. UK, Changeworks. [8]. Changeworks (2009). Renewable Heritage – A Guide to Microgeneration in Traditional and Historic homes. UK, Changeworks. [9]. Changeworks (2010). Double Glazing in Listed Buildings: Project Report. UK, Changeworks. [10]. Bath & North East Somerset Council (2013). Energy Efficiency & Renewable Energy Guidance for Listed Buildings and Undesignated Historic Buildings. UK, BANES. [11]. Changeworks (2012). Solid Wall Insulation in Scotland: Exploring Barriers, Solutions and New Approaches. UK, Changeworks.

More contents on https://energyheritage.wordpress.com/

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

[12]. Low Energy Apartment Futures (LEAF), www.lowenergyapartments.eu [13]. Historic Scotland (2008-present). Technical Papers 1-23. UK, Historic Scotland. [14]. Historic Scotland (2012-present). Refurbishment Case Studies 1-12. UK, Historic Scotland. [15]. Historic Scotland (2012). Short Guide 1: Fabric Improvements for Energy Efficiency in Traditional Buildings. UK, Historic Scotland. [16]. English Heritage (2012). Energy Efficiency in Traditional Buildings guide series. UK, English Heritage. [17]. Society for the Protection of Ancient Buildings (2011-present). The SPAB Research Reports 1-3. UK, SPAB. [18]. Sustainable Traditional Buildings Alliance (2012). Responsible Retrofit of Traditional Buildings. UK, STBA. [19]. Sustainable Traditional Buildings Alliance (2014). Responsible Retrofit Guidance Wheel. UK, STBA. [20]. Sustainable Traditional Buildings Alliance (2014). Moisture Risk Assessment and Guidance (Draft). UK, STBA. [21]. Sustainable Traditional Buildings Alliance (pending). Heat Loss from Thermal Bridging in Internal Wall Insulation of Solid Buildings. UK, STBA. [22]. NDM Heath Ltd (2013). Renewable Energy in Historic Buildings. Sweden, Uppsala University. [23]. Climate for Culture, www.climateforculture.eu

- 109 -

More contents on https://energyheritage.wordpress.com/

International Conference ENERGY EFFICIENCY IN HISTORIC BUILDINGS

MADRID 29-30 | 09 | 2014

- 573 -

More contents on https://energyheritage.wordpress.com/