The Fabric Energy Efficiency Standard

Transcription

1 Nov 2011 More than insulation. The Fabric Energy Efficiency Standard N Ireland Part F Regulations and the higher levels of the Code for Sustainable Homes Affordable Engineered Solutions to Low Energy Design A practical insulation guide for builders and designers to meeting Part F Building Regulations standards and the short step to meeting the Fabric Energy Efficiency Standard for Zero Carbon.

2 GLOBAL WARMING POTENTIAL Xtratherm Innovation - delivering better performance Xtratherm manufacture rigid thermal insulation for new build and refurbishment construction projects that deliver eco-friendly sustainable solutions. Xtratherm s experience and expertise is in providing cost-effective, certified solutions to the construction industry for over twenty years. The comprehensive range of technology foams offer the construction industry choice of specification and ultimately cost effective solutions to achieving Building Regulations and Zero Carbon fabric standards. The guide gives straightforward, affordable insulation solutions to meet the new standards for new dwellings, but as one of the main goals of the update is to work towards Zero Carbon standards, our guidance offers U-value solutions to achieve these advanced performance targets. With these improved fabric standards, it may allow for some more expensive technologies to be omitted and still achieve compliance with NI Building Regulations. Expanded Polystyrene (EPS) Thin-R Warm-R Expanded Polystyrene Enhanced (EPS) GREEN GUIDE A-RATED Rigid insulation technologies - flexible solutions An inexhaustible combination of energy efficient measures are available to the specification builder/designer to meet the new Part F Regulations. However, re-arranging these combinations on a site of different house types with different energy requirements, will lead to confusion and costly errors being made. Showing compliance with an over-ambitious design might result in failure when finished measurements taken are less robust than planned for, leading to expensive remedial costs. A builder/designer should aim to achieve an effective building fabric first - lowering the energy target required - then look at how that energy is supplied. 2

3 More than insulation. Building Regulations Part F in Northern Ireland are due for regular review over the next number of years with the 2012 update delivering a 25% improvement over the previous regulations. Those providing social housing under the Code for Sustainable Homes are now building to levels 4 and even 5 in Northern Ireland. These continuing progressions are steps toward the Zero Carbon goal that the UK Government is committed to within it s policy statement entitled Building a Greener Future - Towards Zero Carbon Development. In N Ireland, the minister has committed to ensure that Northern Ireland building regulations maintain the same standards. This guide demonstrates the fabric solutions required to achieve not just the 25% improvement under the regulations but those futures goals indicated within the Code towards the Fabric Energy Efficiency Standard for Zero Carbon. The starting principal for reducing emissions is to provide a well insulated building fabric as reflected in the latest update to the Building Regulations and the Code for Sustainable Homes. The fabric first approach has been stressed by the Zero Carbon Hub who have defined the Fabric Energy Efficiency Standard for the imminent Zero Carbon Standards. A best performing building fabric, through the attainment of good U-values, thermal bridging reduction with accurate detailing and improved airtightness, reduces the energy requirements, cuts CO 2 emissions and reduces energy bills. The following insulation solutions for Part F compliance have been expanded to include U-values indicative of Zero Carbon Homes. With the Zero Carbon Fabric Standard now in place under the Code and the content of the 2013 and 2016 regulations changes already well formulated the target U-values are readily attainable and might well allow for a reduction in more expensive technologies to achieve Part F compliance when used. Xtratherm offer practical, affordable solutions to meet the highest standards now. House Type 1 House Type 2 House Type 3 Model is 211 m 2 with five bedrooms and three bathrooms over three storeys. Model is 118 m2 with four bedrooms and two bathrooms over two storeys. Model is two storeys with an internal area of 76 m 2, comprising three bedrooms and two bathrooms. 3

4 The 2010 revision aims to: 1. Improve the energy efficiency of new buildings by approximately 25% (compared with those that met the previous 2006 regulations). 2. Improve the correlation between the predicted (TER) and actual (DER) performance of new buildings. 3. Continue along the path towards Zero Carbon buildings within the next decade. 4. To promote improvement of the existing building stock. Regulations now demands a whole building Approach to energy measurement based on carbon dioxide emissions, setting an overall Energy Performance target for new houses. This approach allows greater flexibility in the design but with that flexibility, the complexity of available solutions leaves the design vulnerable to failure. Although the tables contained at the back of this guide give indicative elemental U-values the Elemental approach to compliance is no longer available, a greater understanding of the principals of insulation in energy conservation is required in the context of the whole building approach. A best performing building fabric, through the attainment of good U-values, thermal bridging reduction with accurate detailing and improved airtightness, reduces the energy requirements cuts CO 2 emissions and reduces energy bills. The starting principal for reducing emissions is to provide a well insulated building fabric as reflected in the latest update to the Code for Sustainable Homes. The fabric first approach has been stressed by the Zero Carbon Hub that has defined the Fabric Energy Efficiency Standard for the imminent Zero Carbon Standards. Mixed development sites in Northern Ireland typically involve a number of house types, each with individual characteristics. We have taken this into consideration when formulating our specifications for the house types illustrated. Standardising thickness requirements for the insulation on a site is important. In the examples shown, we have achieved compliance using indicative values for all elements, allowing consistency in material specification for all house types thus reducing wastage and potential errors. The guidance is spilt into building elements, or Thermal Elements ie walls, roofs and floors that separate the internal, conditioned spaces from the exterior, or from unheated spaces. The tables give indicative U-values required for each element and show the thicknesses of insulation required to achieve that target, dependent compliance route is chosen. The full specification for the three house types shown is given on the fold out section at the back of this brochure. Guide to Table Colour Codes Renewable added solution - Fabric U-values required when fabric performance is off-set with Low & Zero Carbon Technologies (See page 16) Part F fabric only solution - Fabric U-values required when fabric is prioritized and LZCs avoided. Fabric Energy Efficiency Standard - Minimum standard indicated under the revised Code for Sustainable Homes for Zero Carbon. Beyond FEEs Standard - U-values indicated by the Zero Carbon Hub as meeting their Zero Carbon Solutions. 4

5 More than insulation. Building fabric insulation Thermal Bridging...the difference is in the detail THE XTRATHERM ADVANTAGE BRE Certification on modelling to BR497 BBA U-value competancy BBA Approved products Certified performance A major factor in the performance of the building fabric is not simply the amount of insulation you install, but how it interconnects with its other components and the other insulated elements within the design. Take a wall construction for example: you may indeed succeed in achieving a very good U-value by increasing the cavity and adding more insulation, but in the well insulated building that is required for Code level 3 (Current Part F) and beyond, most of the fabric heat loss will not be through the main body of the wall, floor or roof - but at the junctions where those elements meet. Jamb Ψ (PSI) value Using Close-R and Lightweight Block Ψ Ψ (W/m 2 K) Xtratherm Value to BR497 (W/m 2 K) Accredited Value 0.05 Default Value 0.10 This is why detailing and jointing of the insulation layer has become a critical factor in energy efficient design. It has been estimated that up to 30% of the heatloss in a well insulated house is through these Non Repeating the performance of non-repeating thermal bridges at wall/floor junctions, corners, reveals, ceiling junctions heads and sills are accounted for in SAP 2009 by the inclusion of a Y value and has a default value of - low and Zero Carbon dwelling require a value of around 0.05 or better to achieve compliance AND to avoid potential condensation and mould problems in highly insulated buildings. The Y value is determined by measuring the thermal transmittance through all the non repeating thermal bridging that is in the design and multiplying this PSI value by the lineal meterage of each. The sum of all these PSI x (m) is then divided by the total area of fabric on the design to determine the Y value for input to SAP. Default figures can be taken from Table K in SAP if calculated PSI values are not available. For further guidance on PSI values and inputting into SAP 2009 see page 16. PARTY WALLS - THE CHANGES The revised Part F has introduced new requirements for party walls.this is to reflect research that shows that party walls with unsealed and/or unfilled cavities have significant convective heat loss into roof spaces. Penalties for not sealing or filling the cavity space between properties makes compliance extremely difficult. However as no target U-values are quoted, low performance, low cost fibrous insulation material will suffice as a cavity fill in this element of the build, along with effective edge sealing. Table 2.3 s for party walls (1) {W/(m 2 K)} Party wall (1) construction Solid 0.0 Unfilled cavity with no effective edge sealing 0.5 Unfilled cavity with effective edge sealing around all exposed edges and in line with insulation layers in abutting elements Fully filled cavity with effective edge sealing around all exposed edges and in line with insulation layers in abutting elements Note: (1) These U-values only apply to the separating walls between dwellings and not to thermal elements such as walls separating a dwelling from the unheated common areas in buildings with multiple dwellings

6 Building fabric insulation Cavity Walls Partial Fill Where exposure to wind driven rain excludes the use of full fill system, Xtratherm XT/CW(T&G) is the best solution in partially filled external masonry walls. Xtratherm boards achieve high standards of insulation whilst maintaining a residual cavity without a substantial increase in the width of the cavity and of the overall wall thickness. Partial Fill Cavity Wall (100mm & 125mm cavity max) Achievable Standards Renewable added solution 50mm Plus Liner* With an additional layer of Xtratherm Thermal Liner XT/TL added to the inner wall improvements in the U-value towards Zero Carbon targets are achieved. There is also a substantial improvement in thermal bridging PSI values achieved. Part F fabric only standard Fabric Energy Efficient standard Beyond FEEs (Zero Carbon) *Overall thickness of thermal liner inc plasterboard. Block W/mK. 75mm 50mm 50mm 50mm 37.5mm 50mm 72.5mm U-values - Partial Fill Insulation Only U-values - Partial Fill with liner Xtratherm CW Block Lambda Basic U-value With Liner* XT (mm) Block Lambda 0.11 Block Lambda mm Block Lambda mm Block Lambda mm Block Lambda *72.5mm overall thickness of thermal liner on dabs 0.022W/mK Thermal Conductivity (Certified) Low emissivity foil with a cavity resistance value of Outstanding thermal performance Robust tongue & groove jointing Clear cavity maintained Technical Approval Certificate No: 07/4407 6

7 More than insulation. Building fabric insulation Cavity Walls Full Fill The Building Regulations are committed to delivering Zero Carbon homes by The Government has now given the U-value targets to achieve Zero Carbon. CavityTherm will achieve the target wall U-value within traditional cavity widths. The CavityTherm wall insulation system works within a traditional 100mm cavity using traditional foundations, building skills and materials to achieve W/m 2 K. Maintaining the standard overall wall width means no loss of living space internally nor an enlarged building footprint. Full Fill Cavity Wall Achievable Standards Fabric Energy Efficient standard Beyond FEEs (Zero Carbon) 100mm 125mm The board includes specifically designed rebated edge detailing on all four edges to allow the system to tightly interlock when installed. *Includes aerated block W/mK with dot & dab plasterboard finish. Robust engineered jointing Installing Xtratherm CavityTherm in a 125mm cavity gives U-values that are indicative of targets set for Zero Carbon Standards - but within traditional construction allowing the architect to design low carbon homes and maintain a reasonable cavity width. Technical Approval Certificate No: 10/4786 Xtratherm CavityTherm has gas tight facings - with one additional HIP skin bonded to provide a drainage plane, directing moisture onto the outer leaf. A specially designed profile maintains a residual channel, protecting the structure. 75

8 Building fabric insulation Timber Frame Walls Xtratherm s Timber Frame Insulation Systems brings Timber Framed wall insulation performance to Zero Carbon levels, surpassing regulation values and meeting those required to meet the Fabric Energy Efficiency Standard and beyond. Timber Frame Wall Achievable Standards Renewable added solution Part F fabric only standard Fabric Energy Efficient standard Beyond FEEs (Zero Carbon) 140mm 140mm 140mm 140mm Includes insulated service void behind plasterboard. *0.19 U value achieved. Plus Liner 25mm* 25mm* 35mm 55mm Using a fibrous glass or stonewool type of material between studs is the most common method of insulating Timber Framed constructions. Although not as efficient in insulation values, the flexibility of the materials allows the insulation to be squeezed between studs with irregular spacings. Placing a lining of Xtratherm XT/SB Sheathing Boards into the traditional cavity of the construction, and effectively insulating the thermal bridging caused by the timber studding dramatically improves the insulation value of the walls. An alternative to applying a Sheathing Insulation into the cavity to improve the thermal bridging factor of the timber, is to place a lining of Xtratherm XT/TF over the studding to the inside face of the construction, thus improving the insulation value of the wall. An insulated service duct can be created by placing counter-battens between the Xtratherm and plasterboard finish allowing services to be placed without compromising the integrity of the vapour control layer and enhancing the air tightness. Technical Approval Certificate No: 08/4613 8

9 More than insulation. Building fabric insulation Thermal Lining Whether you are upgrading an existing property or building new, the addition of an insulated thermal lining to the inside of a wall, roof slope or ceiling will dramatically improve the energy efficiency standards in your home. Mechanically Fixed In many instances, older walls are not suitable for dot and dab application because they present an uneven surface. In such situations, the application of thermal liners using a mechanically fixed system onto timber framing/battens or a metal furring system might be appropriate to provide a level surface. Xtratherm Thermal Liners can also be mechanically fixed directly onto an even wall. Direct Bonding - Dot & Dab Xtratherm supply a range of Thermal Liners with tri-laminate paper facings specifically to accept adhesive type fixing systems such as dot & dab. Adhesive bonding of the Thermal Liners can be made to most masonry surfaces if the walls are plumb and in good condition. Existing plastered walls that are in good condition will also accept the adhesive dabs, any painted surface should be sanded back and treated with a PVA adhesive before applying adhesive dabs. Ribbons of adhesive should be placed around all wall edges and all openings and services on the wall to provide a fire stop and avoid air Technical Approval Certificate No: 04/4130 Thermal lining for new and refurbishment a practical affordable solution Outstanding thermal performance 9

10 Building fabric insulation Sarking Warm Roof Using Xtratherm insulation as a Sarking board to create a Warm Roof construction is a particularly effective way of insulating complex roofs. Roof Warm 600cs (XT/PR between & XT/SK over) Achievable Standards Sarking Renewable added solution 60mm 60mm Part F fabric only standard 70mm 75mm Fabric Energy Efficient standard mm 75mm Beyond FEEs (Zero Carbon) mm 75mm 600mm cs with approved breather membrane. High Thermal Performance Super-efficient U-value in roofs Effective Thermal bridging detailing Fully engineered jointing system Avoids thermal stress in roofs Insulating above the roof timbers ensures that the structure is kept at, or near the internal environmental conditions, reducing thermal stress and condensation risk. It also allows for the valuable area below the rafters to be used as additional living space, or makes access for the placement and maintenance of plant and technologies associated with low energy housing such as PV s, Solar Thermal and MVHR equipment. The Xtratherm Sarking Board XT/SK is a robust T&G engineered jointed board that achieves excellent U-values at minimal thicknesses. An additional layer of Xtratherm between the counter battens minimizes fixing length. Technical Approval Certificate No: 07/

11 More than insulation. Building fabric insulation Pitched Roof - Hybrid Placing Xtratherm XT/PR between and below the rafter offers an effective solutions when insulating dormer style roofs. The high performance to thickness ratio of Xtratherm gives the maximum insulation values with minimal intrusion into the living area below. Roof Hybrid 600cs (XT/PR between & XT/SK over) Achievable Standards Plus Liner Renewable added solution 100mm 42.5mm Part F fabric only standard 100mm 52.5mm Fabric Energy Efficient standard mm 72.5mm Beyond FEEs (Zero Carbon) mm 72.5mm 600mm cs, includes 25mm unvented void beneath breather membrane. The Hybrid Roof utilizes an approved Vapour Permeable (Breathable) underlay above the rafter allowing the traditional 50mm ventilation space to be dispensed with. A 25mm unvented void should be maintained; Agrément certification covering the membrane should be consulted. In a conventional ventilated roof a 50mm clear ventilation gap should be maintained between the insulation and the roofing felt. In certain instances when a vapour permeable membrane is used instead of standard roofing felt, the ventilation gap may be dispensed with. An effective vapour control layer should be installed when using breathable membranes. Placing a layer of Xtratherm Thermal Liner to the underside of the rafter provides a Robust Detail and substantially improves the U-values achieved, with minimum intrusion into valuable living space. Technical Approval Certificate No: 07/

12 Building fabric insulation Ceiling One of the easiest and most cost effective measures to increase the energy efficiency of a dwelling is to insulate the roof space at joist level. Roof Ceiling 600cs (fibre between & over, liner below) Achievable Standards Fibre Between Fibre Over Plus Liner Renewable added solution 100mm 150mm 29.5mm Part F fabric only standard mm 150mm 52.5mm Fabric Energy Efficient standard mm 150mm 72.5mm Beyond FEEs (Zero Carbon) mm 150mm 72.5mm includes 12.5mm plasterboard, 600mm cs With the substantial increase in thicknesses of fibre now asked for, consideration must be given to safe access to the roof space for the maintenance of any services that is placed within the roof space. Adding a layer of rigid insulation to the underside of the joists reduces the thickness of fibre and also provides better thermal bridging detailing at the wall junction. Xtratherm also produce an insulated roof access board that can be used to provide an insulated platform for safe access. Placing a layer of Xtratherm to the underside of the joists not only improves the overall U-value of the roof but crucially provides better thermal PSI value results for the gable junction. This particular junction is one of the major non-repeating thermal bridges that must be addressed to reduce the Y-value for the property as part of the endeavor to achieve low carbon design. Placing fibre glass over the joists hides the top of the joists and may lead to health and safety concerns when the roof space is being accessed. An Xtratherm solution to covering the thermal bridge through the joists is to place a layer of Xtratherm to the underside of the joist before the plasterboard is fixed. Additional fibre can be added above the joists when safe access is provided by the use of Xtratherm Loft Walk-R Outstanding thermal performance Simple installation 12

13 More than insulation. Building fabric insulation Floors Achieving a U-value of W/m 2 K or better should be set as a goal for all floors as the costs of material and installation required to achieve this goal over the current building regulation standards is relatively small. Solid Floor (75mm screed) Perimeter/Area (P/A) FEEs Standard Standard Achieved Beyond FEEs Standard Achieved Suspended Beam & Block Floor (75mm screed) Perimeter/Area (P/A) FEEs Standard Standard Achieved Heatloss from a floor is easily rectified through an increase in the insulation thickness. Xtratherm s thermal conductivity of 0.022W/mK minimizes the thickness required. Detailing at junctions is also critical as heat loss occurs through bad jointing and the floor perimeter. The detailing at the floor/wall junction is critical to avoid thermal bridging. Beyond FEEs Standard Achieved Placing an upstand of Xtratherm insulation at the floor edge will alleviate the problem and is obligatory under the Building Regulations. Xtratherm underfloor insulation is ideal for use with Under Floor Heating systems. It is recommended to provide maximum U-values when UFH is installed. Xtratherm Hyfloor is an engineered jointed, T&G all four edges high performance Under Floor Insulation consisting of a high performance rigid Polyisocyanurate (PIR) core with branded gas tight facings both sides, it has a thermal conductivity of 0.022W/mK. Technical Approval Certificate No: 07/4406 Construction friendly product Tongued & grooved 2400 x 1200mm High compressive strength High cross breaking strength Lambda Value W/mK Certified 13

14 Technical Notes GLAZING / DOOR PERFORMANCE The performance of glazing and doors can have a significant effect on the overall energy performance of a dwelling. Whilst the building regulations ask for an average U-value of 2.2 W/m 2 K to be achieved, a single solid timber door with a U-value of 3 W/m 2 K can mitigate any improvement of glazing below so an overall approach to the specification should be followed. As with other inputs into a SAP calculation, the glazing performance must be accredited by certification for the SAP Assessor to accept the claims; your glazing supplier should be able to provide such certification. The thermal performance of openings depends on a number of factors including the design, the materials used, including the glass, the cavity and framing material itself. Double glazing has now been standard specification for some time, but improvement on the standard performance can be made by the inclusion of certain technologies. Low emissivity coatings on the glass itself, either hard coat low-e or improved soft coat Low E will improve performance. Within the cavity space between the glass, the inclusion of argon gas filling will improve the U-value. And in the design of the frame material itself, thermal breaks within the frame construction can significantly improve overall window U-values. While the specification of better glazing U-values is crucial for low energy design - it is not the only factor. Good air permeability is also reliant on window and door frames being properly sealed. Poorly sealed opening casements and sashes can result in further heatloss. Your window supplier will be able to advise. (see for further information) VENTILATION & AIR PERMEABILITY Air leakage from buildings, the uncontrolled flow of air through gaps and cracks in the fabric of dwellings (sometimes referred to as infiltration, exfiltration or draughts) is a major cause of energy loss and increased CO 2 emissions. Improving airtightness in dwellings will reduce air leakage. Too much air leakage leads to unnecessary heat loss and discomfort from cold draughts. With more stringent building regulations requiring better energy efficiency, airtightness is an increasingly important issue, the new regulations ask for a minimum air permeability of 10m 3 /m 2 /yr at Q10. Our solutions ask for an air permeability of 6 to be achieved. Following the Enhanced Accredited Details should improve the permeability to around 4. The aim should be to build tight - ventilate right. Buildings cannot be too airtight; it is, however, essential to ensure appropriate ventilation. Ventilation, the controlled flow of air into and out of the dwelling through purpose-built ventilators is required to provide good air quality for the comfort and safety of the occupants. Ventilation methods commonly used include trickle vents, extract fans, and openable windows. Whatever method is installed, it should work in harmony with the energy efficiency principle of the house in mind, any mechanical systems will use energy to run. Mechanical ventilation may become necessary as the air permeability is improved better then 4 m 3 /m 2 /h at 50P. At this point combining the ventilation with heat recovery can become very effective - look for efficiencies of the systems and importantly the Specific Fan Power. THERMAL BRIDGING Insulation components should come together to form a continuous layer throughout the design. Enhanced detailing asks that all rigid insulation materials be engineered (T&G) jointed rather than square edge to achieve continuity. Xtratherm have recognised the importance of effective jointing of components and elements and have developed innovative system components to improve overall insulation performance. In walls, the Xtratherm insulation system includes preformed corner panels and reveal panels for openings that knit with the main cavity wall insulation perfectly. In roofing the Xtratherm Rafterloc pre-cut rafter panels expand to fill rafter spaces whilst in the floor our Hyfloor boards now come with full T&G jointing and perimeter strip. For full details see the installation animations on or contact Xtratherm Technical Support for full Thermal Bridging information. 14

15 More than insulation. Technical Notes (cont d) RENEWABLES Low & Zero Carbon Technologies (LZCs) As previously mentioned, the first step in energy efficiency in new build is to provide a robust, energy efficient building fabric before incorporating any Low or Zero Carbon Technologies (LZCs). It does not make sense to install renewable generation into a design if much of the output is to be wasted through inefficient usage. The building fabric will last a lot longer than the services that are put into it. Most technologies such as boilers, glazing, and renewables will be replaced within one or two decades. It is therefore vital to get the fabric right at time of construction. It is always more costly to insulate properly at a later stage. Solar Gain The Free energy good design takes advantage of solar gain, but difficult to predict and control in the our climate. When designing to take advantage of solar gain, the heating and ventilation system used within the design should be very responsive to temperature fluctuations. Solar Water Heaters Can provide up to 50% of hot water requirements on a SE-SW roof, available as flat plate or vacuum tube systems, normally require the installation of higher volume storage cylinders. Photovoltaics (PV) Uses energy from the sun to create electricity to run appliances and lighting. PV requires only daylight to generate electricity. A typical array would cover 10-15m 2 of roof area. HEATING Energy to heat the space will be necessary in all houses including Passive/Low carbon houses at certain periods in the year. The task is to supply that energy requirement as efficiently as possible by choosing a cleaner fuel - natural gas is cleaner than oil or electricity, and burning it as efficiently as possible, boilers should perform above the 86% minimum efficiency but can be sourced over 90% efficient. Burning biomass - logs or pellets which are carbon neutral will also reduce carbon production. Heating Controls - Boiler based heating systems should incorporate: space heating control on the basis of room temperature (room thermostats and/or TRVs); water heating control on the basis of stored water temperature (cylinder thermostats); separate and independent time control of space heating and water heating; and boiler interlock (i.e. the boiler does not fire when there is no demand for space or water heating). Equivalent control should provided for other types of systems. Good practice guide CE51 from the BRE gives invaluable information on the specification of control systems. ENERGY EFFICIENT LIGHTING As we achieve better control of space heating through effective insulation of the building fabric and good control of our hot water needs - the energy demand for lighting becomes a bigger proportion of the energy demand and a major contributor to CO 2 production, not least because the energy is electric based which is a costly fuel and dirtier than all other fuels. Using energy efficient light fittings will reduce CO 2. Although we should aim to have 100% energy efficient lighting - fashions dictate that this is not always possible and should be reflected as such in the calculations. Pellet Stoves Energy from biomass is produced from organic matter of recent origin - not fossil fuels. The CO 2 released during burning is balanced by the CO 2 absorbed during the fuel s production - this is Carbon Neutral. Storage of pellets is a major consideration. Ground Source Heat Pump The ground keeps a constant temperature of about 11-12ºC. Ground source heat pumps (GSHP) can transfer this heat into a building to provide space heating. For every unit of electricity used to pump the heat, units of heat are produced. Particularly suitable for under floor heating because of lower operating temperatures. 15

16 The Xtratherm Advantage Why engineered detailing delivers. Regulations now place greater emphasis on thermal bridging and the importance of better detailing. The energy assessor is asked to input a figure into SAP in the form of a Y value that indicates how the insulation system has been installed, but in terms of BENEFIT what does Xtratherm detailing actually deliver? U-values are readily understood, but the claims of excellent U-values without being able to witness the detailing at junctions whilst the insulation is being installed renders the insulation system almost worthless. The other factor of Air Permeabilty is also well understood and a good airtightness is important in low energy design - but can we compare the energy benefits of the detailing to airtightess or even renewable input? The following table illustrates the relationship between these principles. Taking a standard semi-detached property with a specification to achieve 2011 standards we can see the benefit of good thermal bridging detailing - and of crucial significance, it comes FREE with Xtratherm Cavity-Therm. Fabric performance is now the key factor in delivering Zero/Low Carbon design and consists of 3 elements: U-values Thermal Bridging Air tightness Semi-detached House - TER Total Envelope Area = Which details to use? Default # Accredited # Xtratherm (Mech Vent Reqd.) (Mech Vent Reqd.) Junction Detail Length (m) Ψ (W/m 2 K) Ψ (W/m 2 K) Ψ (W/m 2 K) Lintels Sill Jamb Ground Floor Intermediate floor Corner (normal) Corner (inverted) Ceiling (insulation at eaves) Ceiling (insulation at gables) Party Ground Floor Party Wall (intemediate floor) Party Ceiling (insulation at ceiling) Total L x Ψ Example House Y-Value (L x Ψ/total area) Additional measures for compliance Air permeability m 3 /m 2 /hr 0.05* 3* 8 (default) Renewables Solar water (m 2 ) 2 DER *Mechanical ventilation required # Default & accredtited values are taken from Table K1 in SAP 2009 Specification U Value TER (W/m 2 K) Walls 100mm Xtratherm CavityTherm* Floors 100mm Xtratherm Hyfloor 0.16 Revaels Close-R proprietary reveal closers Ceiling 300mm fibre glass Glazing Boiler Combi 90% EE Lighting 100% *Dense Block 16

17 More than insulation. Part F Compliance: Specification and U-value targets. General Spec based on: Low energy lights 100% Thermal bridging 0.08 Gas boiler (Combi) 90% Heating controls Weather compensator Thermal mass Full T&T Yes Medium Detached House - TER DESCRIPTION PART F FABRIC MECHANICAL SOLUTIONS ONLY STANDARD SOLAR PANELS PV PANELS MVHR Walls 0.25 Floors 0.17 Roof (Ceiling) 0.10 House Type 1 Roof (Sloped) Semi E wall Semi E Floors Model is 211 m 2 with five bedrooms and three bathrooms over three storeys. Dormer cheek Windows Doors Air Permeability Renewables 5m 2 (Gross) 0.6 KWp MVHR SFP 0.85 eff 90% DER Semi-detached House - TER DESCRIPTION PART F FABRIC MECHANICAL SOLUTIONS ONLY STANDARD SOLAR PANELS PV PANELS MVHR Walls Floors 0.17 Roof House Type 2 Windows Doors Air Permeability Model is 118 m 2 with four bedrooms and two bathrooms over two storeys. Renewables 4m 2 (Gross) 0.5 KWp MVHR SFP 0.85 eff 90% DER Terrace House - TER DESCRIPTION PART F FABRIC MECHANICAL SOLUTIONS ONLY STANDARD SOLAR PANELS PV PANELS MVHR Walls 0.25 Floors Roof (Ceiling) 0.10 House Type 3 Roof (Sloped) Roof (Flat) Dormer cheek Model is two storeys with an internal area of 76 m 2, comprising three bedrooms and two bathrooms. Windows Doors Air Permeability Renewables 2m 2 (Gross) 0.4 KWp MVHR SFP 0.85 eff 90% DER

18 GLOBAL WARMING POTENTIAL Technical Support Xtratherm Technical Support team provide a single point of contact to offer assistance on a wide range of issues for both the designer and builder and can be contacted by phone, fax or . Full details of all Xtratherm products, along with full technical literature can be downloaded from the website at: Xtratherm UK Limited Park Road, Holmewood Chesterfield, Derbyshire S42 5UY Tel: Fax: info@xtratherm.com ISO 9001 Quality Management Systems ISO Environmental Management ISO Occupational Healty & Safety GREEN GUIDE A-RATED Good workmanship and appropriate site procedures are necessary to achieve expected performance. The information contained in this publication is, to the best of our knowledge, true and accurate but any recommendations or suggestions which may be made are without guarantee since the conditions of use are beyond our control. Xtratherm reserve the right to change the content of this publication without prior notice.