• Thermal Bridges in new Dwellings.....
• Accredited details – • Designing & detailing for Compliance
Danny Kearney
Main changes to Part F for dwellings
Regulations Part F 2012 – ComplianceFabric Solutions & Thermal Bridging
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31st Jan 2013
Lisburn and Castlereagh City Council
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Presentation - Danny KearneyPresentation - Danny KearneyGroup Technical ManagerGroup Technical Manager
Contact - [email protected] - [email protected]
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1. Explain the 3 components to fabric performance – how do they compare?
U-valuesAir tightnessThermal Bridging
2. Take a semi and look at compliance specifications3. Calculating your Y value.4. Where is it likely to end up? 5. (Zero Carbon Standard & FEEs)Xtratherm – Expect More
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Criteria 1 – Achieving the TER Design stageCalculate CO2 emissions for the proposed building – using SAP
Criteria 2 – Minimum Acceptable Stds Design StageKeep within Design limits set in Document
Criteria 3 – Limit Overheating Design StageLimit Solar Gains in Summer (Over Heating)
Criteria 4 – Const Quality & Commis. Post ConstructionCheck Quality of Construction and commissioning of building services
Criteria 5 – Instruction for operation Post ConstructionProvide Information to the home owner
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Criteria 4 – Const Quality & Commis. Post Construction•Evidence As stated in paragraph 2.21, a recalculation of the DER is required to be given to the district council not more than 5 days after completion of the dwelling taking into account any changes in performance between design and construction and the achieved air permeability and to demonstrate that the DER for the dwelling as constructed meets its TER.•Building envelope 2.43 The building envelope should be constructed to a reasonable standard such that the insulation is reasonably continuous over the whole building envelope and the actual air permeability is within the set limits.•Party Walls Sealing must be effective – Robust (Sound Detailing) must be taken into account.•Thermal bridges 2.51 The building fabric should be constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps within the various elements, at joints between elements, and at the edges of elements such as those around window and door openings.
Criteria 4Quality & Commisioning
The TER and DER for the dwellin
g should be included with the operating
and maintenance instructions together w
ith the data used to calculate them.
This should include an electronic copy of th
e TER/DER data input file for
the
dwelling to facilita
te any future analysis that may be re
quired by the owner
when altering or improving the dwellin
g.
Pressure testing – Penalties Added• (i) where the dwelling has been pressure tested, the assessed air
permeability is the measure air permeability; or
• (ii) where the dwelling has not been pressure tested, the assessed air permeability is the average result obtained from pressure tests on other dwellings of the same type on the development increased by a margin of +2 m3/(h.m2) at 50 Pa; or
• (iii) on small developments, where the person carrying out the work has opted to avoid testing the assessed air permeability is 15 m3/(h.m2) at 50 Pa.
Accredited Detailing - Penalties Added
If not calculated – PSI values MUST be taken from SAP 2009 Table Either Default or Accredited
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Criteria 4Quality - PENALTIES
NO EVIDENCE? - Penalties Will Be Added
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So how to comply?
U-values
Airtightness
Thermal Bridging
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Code for Sustainable Homes?
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• F1 same as Code 3• FEES introduced• FEES will lead Regulations Eng & Wales
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Compliance with Part F 2012 using SAP 2009.
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So – What needs done?
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How to achieve compliance – the 25%
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RESULTS TER DER
18.24 18.24
Element Spec Result
Wall 100mm CavityTherm
0.20
Floor 100mm Hyfloor 0.16
Ceiling 300mm Fibre 0.15
Glazing Double 1.6
Doors Double 1.6
100% EE Lighting – 90% Combi Gas Boiler – Full TT Zoning -
Other
Block Dense
Mech Ventilation None
Renewables None
Permeability 5
Bridging Y value
Xtra Details
0.04
Compliance 1Good detailing
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Partial FillCavity Wallusing foiled faced PIR
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Meeting the U-values: Walls - Partial Fill
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Full FillCavity WallPIR 0.021
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Meeting the U-values: Walls - Full Fill Built in
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Floors using foiled faced
PIR
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Meeting the U-values: Floors
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Roof – Slope using foiled faced PIR
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Meeting the U-values:Roofs - Slope
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Roof - Ceiling using foiled faced PIR
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Meeting the U-values: Ceilings
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Full FillPumped
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Meeting the U-values: Walls - Full Fill Built in
175mm – 0.21 U-ValueY-value: Detailing?
Cost Report availableXtratherm – Expect More
PARTIAL FILL
SQUAREor
T&G
Meeting the U-values: Walls - Full Fill Built in
Did you know – There a U-value penalty of 0.01 if your
boards are not engineered jointed?Xtratherm – Expect More
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Taking the same house –
Calculating the actual Y-value
using the:
•Length of each junction
•The PSI value of each junction
•The total area of heat loss
(Envelope area)
Thermal BridgingTaking advantage
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• Non–Repeating Thermal Bridges.• Account for 30% of heat loss from a well insulated house• Cold spots cause condensation and mould growth• MUST be measured under part F• Account as a Y-factor in SAP
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Each Junction has a PSI value – found in Table K of SAP 2009
Either
DEFAULT or ACCREDITED
Or
Use measured performance from accredited source
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Criteria 4 – Thermal Bridging – Accredited Details• Bridging Calculation to BRE Report BR 497 Conventions for calculating linear thermal transmittance and temperature factors. ….no worse than (Default) in BRE IP 1/06 or Table K in SAP
•…….that an appropriate system of site inspection is in place
Dwellings constructed to quality assured accredited construction details?
•Where quality assured accredited construction details the calculated linear thermal transmittance can be used …….. Schemes that provide such construction details also accredit and quality assure the calculation of the linear thermal transmittance, accredit the details in terms of buildability and have an associated quality assurance regime that inspects a sample of sites to confirm that the details are being used correctly. CURRENTLY NOT AVAILABLE ANYWHERE
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Criteria 4Quality & Commisioning
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Which details to use? Default# Accredited# XtrathermJunction L ψ ψ ψ
Lintels 13.97 x 1.00 0.30 0.01Sill 12.17 x 0.08 0.04 0.04Jamb 29.55 x 0.10 0.05 0.00Ground Floor 19.60 x 0.32 0.16 0.16Intermediate Floor 19.60 x 0.14 0.07 0.06Corner 10.20 x 0.18 0.09 0.05Corner inverted 20.40 x -0.18 -0.09 -0.05Ceiling (Insulation at eaves) 11.00 x 0.12 0.06 0.05Ceiling (Insulation at gables) 8.90 x 0.48 0.24 0.20Party Ground floor 8.90 x 0.08 0.08 0.08Party wall Intermediate floor 8.90 x 0.00 0.00 0.00Party Ceiling (Insulation at ceiling level) 8.90 x 0.12 0.12 0.12Total (L x ψ) 32.45 14.32 8.54Y Value (L x ψ / Total Area) 0.17 0.08 0.04
Semi Detached House TER 18.24Total Envelope Area = 190.580
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How to achieve compliance – the 25%
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RESULTS TER DER
18.24 18.24
Element Spec Result
Wall 100mm CavityTherm
0.20
Floor 100mm Hyfloor 0.16
Ceiling 300mm Fibre 0.15
Glazing Double 1.6
Doors Double 1.6
100% EE Lighting – 90% Combi Gas Boiler – Full TT Zoning -
Other
Block Dense
Mech Ventilation None
Renewables YES 2m2 Solar HW
Permeability 5
Bridging Y value
Accredited 0.08
Compliance 2Accredited detailing
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How to achieve compliance – the 25%
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RESULTS TER DER
18.24 18.24
Element Spec Result
Wall 100mm CavityTherm
0.20
Floor 100mm Hyfloor 0.16
Ceiling 300mm Fibre 0.15
Glazing Double 1.6
Doors Double 1.6
100% EE Lighting – 90% Combi Gas Boiler – Full TT Zoning -
Other
Block Dense
Mech Ventilation
Required
Renewables YES 5m2 Solar HW?????
Permeability <4
Bridging Y value Default 0.15
Compliance 3Default detailing
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THERMAL BRIDGING – What are Accredited/Acceptable Details
Thermal BridgingTaking advantage
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Xtratherm Accredited Detailing
Based on UK & NI Accredited and
Acceptable Details – same inspection and
reporting regime.
Keep it simple.
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Where’s the end game?
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Fabric Energy Efficiency Standard (FEES or ‘full FEES’). …..the Government has committed to introducing a fabric standard for zero carbon homes, but up until now has not stated when or how such a standard will start to be introduced ….
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CSH Updated
Oct 2
010‘’The adoption of the Code for Sustainable Homes states the intended direction of future changes to Part L of the Building Regulations, which will make dramatic improvementsin reducing CO2.
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New for 2010 CSH
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The metric is kWh/m²/yr covering space heating and space cooling energy demand (modelled utilising a notional dwelling assuming natural ventilation and
excluding any internal gains from the domestic hot water system)
LOOK FOR FEEs SCORE ON YOUR SAPXtratherm – Expect More
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Crest Nicholson - Epsom
Barrett Const - Corby
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• Thermal Bridges – such as at stepped cavity trays have until now been ignored – they MUST now be accounted for.
Insulate behind the line of trays – How does pumped insulation reach these areas?
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Why Xtratherm?
BBA U-value and Condensation risk analysis competency scheme x 4
ISO 9001 | Quality Management SystemsISO 14001| Environmental ManagementOHSAS 18000 | Occupational Health & Safety
Technical Services
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[email protected]@xtratherm.com
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