A Victorian Semi in South Manchester
Street view
A semi-detached house built around 1901 with a near bottom of the class EPC rating from 2011 of F (28); it had solid walls, 25mm of loft insulation, no floor insulation, and single glazed windows. Transforming the house into a low energy home was going to be a retrofit challenge but is now complete.
A new system boiler was added in 2016 by the previous owner leaving the old and barely insulated hot water cylinder. The first challenge was to decide whether to add a new hot water cylinder. The factors were that the orientation of the house was far from optimal for solar thermal and PV, and with much reduced government support financial returns were very long term. The cost of the cylinder was also a factor and a decision was made to change the boiler to a Vaillant combi with advanced weather compensating vSmart controls.
An assessment followed by Red which gave the house an EPC rating of E (55); the rating had improved with the change of boiler and low energy lighting. Measures included deep wall insulation to the side and rear, new triple glazed windows, secondary glazing to some existing windows, loft and room in the roof insulation, and air tightness measures with a new whole house ventilation system. Our energy advisor called it the best example of a pre-retrofit house that he had seen.
The most recent EPC from June 2019 gives a rating of C (79) with scope for improvement should solar PV be fitted. Reductions of 65% in CO2 and 63% in primary energy use have been achieved along with correspondingly lower energy bills.
Update 12 June 2019
A new system boiler was added in 2016 by the previous owner leaving the old and barely insulated hot water cylinder. The first challenge was to decide whether to add a new hot water cylinder. The factors were that the orientation of the house was far from optimal for solar thermal and PV, and with much reduced government support financial returns were very long term. The cost of the cylinder was also a factor and a decision was made to change the boiler to a Vaillant combi with advanced weather compensating vSmart controls.
An assessment followed by Red which gave the house an EPC rating of E (55); the rating had improved with the change of boiler and low energy lighting. Measures included deep wall insulation to the side and rear, new triple glazed windows, secondary glazing to some existing windows, loft and room in the roof insulation, and air tightness measures with a new whole house ventilation system. Our energy advisor called it the best example of a pre-retrofit house that he had seen.
The most recent EPC from June 2019 gives a rating of C (79) with scope for improvement should solar PV be fitted. Reductions of 65% in CO2 and 63% in primary energy use have been achieved along with correspondingly lower energy bills.
Update 12 June 2019
- The sash windows to the first and second floors were replaced by new triple glazed sash windows from Green Building Store.
- Two new triple glazed Velux roof windows were installed, one over the stairs, the other in the 2nd floor ensuite.
- A replacement bay window was fitted in the front living room, with the stained glass releaded and set behind double glazed units; the fixed and opening casements are triple glazed. A replacement triple glazed window with a 'Manchester' roof light was fitted at the side of the house. In the front door the stained glass panels were backed by laminated glass reducing draughts and improving security.
- Insulation was added with air tightness measures: Phenolic insulation to the room in the roof for the roof and eaves; 100mm of Udi IN RECO wood fibre internal wall insulation to external walls, with 25mm of Udi 2INCM to return walls finished with lime plaster; 170mm of mineral wool under the floor of the lounge and hall; 410mm of mineral wool has been fitted in the attic floors.
- Radiators were replaced with smaller, more efficient models with TRVs.
- An MVHR whole house ventilation system with a Paul Novus 300 unit designed by Green Building Store was installed after exploring options including MEV. In the end MVHR offered a more complete solution. The air tightness achieved after the retrofit (as measured in August 2018) wasn't ideal at 6 air changes per hour. However after this a major source of air penetration was found and dealt with and a further informal air test demonstrated how a much lower figure would be expected.
- A small extension to the rear designed by Gibson Architects was built creating a new kitchen/diner from the rear living space; the space occupied by the old kitchen was converted to provide a study, cloakroom and WC. The extension incorporates IdealCombi terrace doors and windows, Fakro roof windows, and new walls and ceilings with low U-values. The garden was landscaped to link the extension with the garden.
- Further measures focusing on the basement may be pursued in future.
The original water tank just under the uninsulated and unlined slate roof
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Bringing in the new triple glazed sash windows
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Installing the new sash windows
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New bay window with releaded stained glass. The internal wall insulation is shown before treatment to surrounds and plastering
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The 'room in the roof'/ Bedroom 4 after the ceiling was removed and before 150mm of insulation was added
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Loft insulation, 1960s style?, 25mm deep
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Pipework routes in attic after 'thinning out' redundant pipework - showing scope for sealing up for air tightness
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Insulation and membrane under the hall floor, sealed at the edges
Rear extension
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