Prepared by Frank Cooney B.Arch MRIA BUILDING REGULATIONS – TECHNICAL GUIDANCE DOCUMENT: PART L, 2011 Conservation of Fuel and Energy - Dwellings Prepared by Frank Cooney B.Arch MRIA Existing c.1850 House With An Extension. Existing House Is Not A Protected Structure.  24th November 2011

 24th November 2011

 24th November 2011

An Victorian terrace house which is not a Protected Structure. Case Study 1 An Victorian terrace house which is not a Protected Structure. No Extension. No Material Alterations. No Window Replacement. No Boiler Replacement. Existing Energy rating - F Part L applies to existing buildings where a Material Alteration takes place. Part L applies to the specific element that is changed when a Material Alteration occurs. What is a Material Alteration? Conclusion For this example no Material Alterations, therefore Part L does not apply.  24th November 2011

Case Study 2 Extension To Rear New Opening In Rear Wall No Works To Existing Building No Window Replacement No Boiler Replacement Part L applies to the extension Part L applies to the opening in the rear wall as it is a Material Alteration. Part L does not apply to the remainder of the existing house.  24th November 2011

Conclusion Fabric Insulation: U-Values for the extension are those which apply to a new build. See Table 1 TGDL CO2 Emissions: Not applicable. DEAP calculation not required for extension.* - DEAP calculation must be carried out on the entire dwelling if it is being sold. Thermal Bridging: Should be limited/omitted. ‘Reasonable care’. Use ACD’s. Air Tightness: ‘Reasonable care” should be taken to ensure unwanted air infiltration does not occur. Use ACD’s. Space and Hot Water Heating Systems: Existing not being altered as boiler has sufficient capacity, therefore Part L does not apply. If extension is separated from house by door/glazed screen, and if it contains a heating facility it must have provision for automatic temperature and on/off control. Hot Water Storage Vessels, Pipes and Ducts: Existing not being altered, therefore Part L does not apply Ventilation: Background ventilation required to comply with Part F of the Building Regulations. * We recommend that a DEAP calculation is carried out regardless of Part L non requirement  24th November 2011

Refurbishment of the Existing House with no extension No Extension. Case Study 3 Refurbishment of the Existing House with no extension No Extension. Windows Replaced Boiler replaced Internal Structural Wall Removed Part L applies to works on the windows and boiler only. The removal of the wall is a Material Alteration, however Part L does not apply as it is an internal wall. Part L does not apply to the rest of the house as works are deemed to be repair and renewal, no material alterations occur.  24th November 2011

Conclusion Fabric Insulation: U-Value applies to windows only. The maximum U-Value permitted is 1.6W/m2K (Table 5)*. CO2 Emissions: Not applicable. DEAP calculation not required but it is recommended. Thermal Bridging: Applies to windows and reveals. Air Tightness: Applies to windows and reveals. Space and Hot Water Heating: - Part L does apply. - Boiler must be of 90% efficiency. - Controls/Zoning - Lagging and insulation. Ventilation: Background ventilation required to comply with Part L**. Upgrading sliding sash windows to 1.6W/m2K is a challenge. ** Increased condensation risk.  24th November 2011

Case Study 4 (What was actually carried out.) Structural Works Carried Out - Material Alteration. B1 Rated. ( 10 kilowatts short of A3). Comprehensive Upgrade of Existing Fabric - Existing Fabric In Very Poor Condition. - Existing roof timbers deteriorated, old non breathable felt. - Lime plaster to walls delaminated. - Some existing walls previously dry lined with plastic sheeting resulting in rot in joist ends. - Floor joists ends rotten - Moisture ingress at basement/lower ground floor level - Windows in poor condition - Heating system - fire and storage heaters only  24th November 2011

Part L applies to the extension. Part L applies to the existing building. Part L applies to the replacement boiler and windows. Conclusion/Works Carried Out to Existing Building Fabric Insulation: Roof U-Value required, 0.25W/m2K, Actual U-Value achieved, 0.16W/m2K. Gutex on existing rafters. Cellulose between rafters with ‘intelligent’ air tightness membrane. External Walls: U-Value required, 0.55/0.35W/m2K, U-Value achieved, 0.31W/m2K. - Plasterboard, not foil backed, on ‘intelligent’ air tightness membrane. Thermally broken metal stud with breathable insulation. Detailed condensation risk analysis carried out, quality control at installation of membrane. - Ground Floor: U-Value required, 0.45W/m2K. U-Value achieved, 0.18W/m2K. Concrete on 200mm insulation on tanking membrane. Quality control re: detailing to eliminate cold bridges and achieve continuous air tightness.  24th November 2011

- Windows: Sliding sash restored - Windows: Sliding sash restored. Double glazed using system approved by Scottish Heritage. Air tightness at shutters and wall junctions. CO2 Emission: DEAP calculation carried out. Thermal Bridging: Detailed analysis using Therma/Wufi software. Careful detailing to avoid cold bridging and condensation. Air Tightness: Internal air tightness membrane. Air tightness/’intelligent’ membrane - Quality control systems/continuity. - ‘Balloons’ fitted in existing chimneys. Blower Door Test: 1.8 m3/hr/m2 - ‘ Balloons’ in chimneys - HRV fitted Solar Thermal - subject to Planning Permission - 600ltr buffer tank- 5 heating zones- thermostats on all zones

Conclusions/Works Carried Out To Extension Fabric Insulation: - Roof U-Value required, 0.16W/m2K. U-Value achieved, 0.14W/m2K. - Wall at upper ground floor, timber frame. U-Value required, 0.21W/m2K. U-Value achieved, 0.12W/m2K. - Wall at lower ground floor, wide cavity masonary construction. U-Value required, 0.21W/m2K. U-Value achieved 0.13W/m2K. - Lower ground floor, raft foundation on super grund. U-Value required 0.21W/m2K. U-Value achieved, 0.18W/m2K. - Triple glazed 0.8 U-Value windows to rear, restored sliding sash to front.  24th November 2011

CO2 Emissions: DEAP calculation carried out for extension and existing dwelling. Thermal Bridging: Therma/Wufi analysis carried out on all details. Air Tightness: Internal air tightness membrane. Air tightness/ ‘intelligent’ membrane - quality control systems/continuity. Blower Door Test: 1.5 air changes. - ‘ Balloons’ in chimneys - HRV fitted Solar Thermal - subject to Planning Permission - 600ltr buffer tank- 5 heating zones- thermostats ion all zones  24th November 2011

does not apply to the existing dwelling which remained untouched. Conclusion: Case Study 1: Repair and Renewal - Part L does not apply as no Material Alteration took place. Case Study 2: Extension to Rear - Part L applies to the extension and rear wall of the existing dwelling as a material alteration occured in the form of an opening. However it does not apply to the existing dwelling which remained untouched. Case Study 3: Refurbishment of the Existing House with no Extension - Part L applies to the works on the windows and boiler only. Part L does not apply to the rest of the house as works are deemed to be repair and renewal, no material alterations occur. Case Study 4: Refurbishment of Existing and Extension to the Rear - Part L applies to the entire dwelling, the extension and the existing as Material Alterations were carried out. The U-Values of the existing dwelling must comply with Table 5 of TGDL and the U-Values of the extension with Table 1 of TGDL. Part L also applies to the boiler and all windows.  24th November 2011

Frank Cooney B.Arch MRIA  24th November 2011