Grove Cottage
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as PDF Extension & Refurbishment of Victorian Townhouse using Passivhaus methodology and CarbonLite guidance. Certified to the Passivhaus Institute's new EnerPHit (refurbishment) Standard. [NEW:Passivhaus Trust awards shortlisted project - presentation available on these pages].PHPP certification is based on 20 C, rather than the 21 C the house was heated to during 2010/11. Forecasts are based on a 'typical year' rather than the 'actual' year being monitored. Measured data here is from 2005/06 (before) and 2009/10 (after). Measured room temperatures show an average of 21 degrees centigrade during the heating season. Please note the final air leakage as certified under EnerPHit was an N50 of 1.0 ACH. When adjusted for 2010 average monthly temps.& an internal temp. of 21 C, PHPP predicted a space heat demand of 36kWh/m2.a whereas 35kWh/m2.a was measured.
Grove Cottage : Project images
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Energy and fuel use
Measured data from renewable generation is not yet available.
Fuel use
| Pre-development | Forecast | Measured | |
| Electricity use | 4300 kWh/yr | 2728 kWh/yr | 3312 kWh/yr |
|---|---|---|---|
| Natural gas use | 24000 kWh/yr | 6724 kWh/yr | 6937 kWh/yr |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 284 kWh/m².yr | 108 kWh/m².yr | 120 kWh/m².yr |
|---|---|---|---|
| Annual CO₂ emissions | 55 kg CO₂/m².yr | 22 kg CO₂/m².yr | 25 kg CO₂/m².yr |
| Annual space heat demand | - | 25 kWh/m².yr | 35 kWh/m².yr |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| Renewables Technology | - | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | 108 kWh/m².yr | 120 kWh/m².yr |
| Annual CO₂ emissions offset by renewable generation | 22 kg CO₂/m².yr | 25 kg CO₂/m².yr |
Calculation and targets
| Whole house energy calculation method | PHPP |
|---|---|
| Other whole house calculation method | PHPP results (EnerPHit certification file) are based on 20 C internal temps and standrd 'typical year'. |
| Energy target | EnerPHit |
| Other energy targets | - |
| Forecast heating load | 13 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | 16 July 2010 | 0.88m³/m².hr @ 50 Pascals |
Project description
| Stage | Occupied |
|---|---|
| Start date | 11 July 2008 |
| Occupation date | 01 March 2009 |
| Location | Hereford Herefordshire England |
| Build type | Refurbishment |
| Building sector | Private Residential |
| Property type | Semi-Detached |
| Construction type | Solid Brick |
| Other construction type | |
| Party wall construction | |
| Floor area | 135 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |  Passivhaus certified building |
Project Team
| Organisation | Simmonds.Mills Architects |
|---|---|
| Project lead person | Andrew Simmonds |
| Landlord or Client | Andrew Simmonds, Lorna Pearcey |
| Architect | Simmonds.Mills Architects |
| Mechanical & electrical consultant | Alan Clarke, Peter Warm |
| Energy consultant | David Olivier |
| Structural engineer | Bob Johnson |
| Quantity surveyor | None |
| Consultant | None |
| Contractor | Eco-DC |
Design strategies
| Planned occupancy | 2 adults and 3 children. |
|---|---|
| Space heating strategy | Passive Solar + Mechanical Ventilation & Heat Recovery (MVHR) + replacement gas boiler inc. retention of existing radiators |
| Water heating strategy | Replacement gas boiler + super insulated, solar ready hot water cylinder + all hot and cold water pipes insulated. Installed measures include a south facing roof area constructed to allow future installation of 4.5 m2 of solar thermal panels to feed into HWC |
| Fuel strategy | Natural gas (minimised use of). Biomass not considered as appropriate fuel due to resultant air pollution issues (particulates etc) in a city residential area, combined with high capital costs associated with biomass equipment relative to low heat demand required. |
| Renewable energy strategy | No electricity generation technologies currently adopted. |
| Passive Solar strategy | Passive solar gain maximised as far as possible mainly through creation of new South facing windows in existing house and new extension. |
| Space cooling strategy | Existing house on N-S axis (main elevations East and West). Use of new & retention of existing thermal mass (blockwork / brickwork) within insulation envelope (i.e. use of external insulation). Windows - summer shading as result of window set back. MVHR has automatic summer bypass allowing automatic cooling at night during hot spells. More substantial rate of night time ventilation for cooling purposes also possible via openable windows (good arrangement for passive stack ventilation designed in). |
| Daylighting strategy | Extensive daylighting to all rooms to displace electric lighting. Maximising daylighting through careful sizing and design of windows and internal colour scheme (favours light off white colours). Some windows with splayed reveals (opportunity arising with existing house) - increase light distribution and levels. |
| Ventilation strategy | MVHR provides ventilation with openable windows if required, (good arrangement for passive stack ventilation designed in). |
| Airtightness strategy | Existing house: external face of existing brick walls parged (thin layer of cementitious material used). New extension: internal plaster to blockwork walls + use of air-vapour barriers in ceilings and some limited wall areas where timber frame was required above brick/blockwork. |
| Strategy for minimising thermal bridges | Adoption of 'thermal bridge-free' construction detailing for new construction and also in refurbishment work where possible. |
| Modelling strategy | PHPP. Limited use of THERM. |
| Insulation strategy | *Application of external insulation to solid brick and new blockwork walls*Insulation of existing suspended floor*Insulation of existing solid floor*New floor raft foundation with structural eps insulation below*Renewal of existing roof and placement of insulation above existing rafters. New roof uses fully filled I beams. |
| Other relevant retrofit strategies | Family remained in house during all refurbishment and new build works. |
| Contextual information | House had limited architectural detail on street facade: Painted brickwork. (Decayed) stone subcills to windows: (Painted) stone lintels visible above windows. An original carved stone plaque was mounted on the house wall. The subcills and lintels details have been recreated in the new render. The street side entrance porch will be rebuilt in timber and roofed in original slates. The plaque will be recreated, updated and mounted as before. |
Building services
| Occupancy | As per stage 2 |
|---|---|
| Space heating | Vaillant natural gas non-system boiler with Alpha Pro 2 external circulating pump etc |
| Hot water | HWC details, insulated pipe details |
| Ventilation | Paul etc Heat Recovery Ventilation Unit, frost protection preheater. |
| Controls | Set for continuous heating - wall mounted Vaillant digital control and room thermostat and weather compensation |
| Cooking | Existing gas hob, electric oven, electric toaster ...coffee maker with insulated jug, microwave. |
| Lighting | 100 % compact fluorescent. |
| Appliances | *fridge: Baumatic BFE 25655 *washing existing appliances: AEG Oko-Lavamat 74630 *dishwasher: ISE DW51 *electric tumble drier - (now junked), MVHR serviced clothes drying cupboard. Also home office equipment; 2 laptops, 2 printers, router, office lighting. Home office is not separately metered. |
| Renewable energy generation system | None |
| Strategy for minimising thermal bridges | 'Thermal bridge-free' strategy. For details - see uploaded documents |
Building construction
| Storeys | 3 |
|---|---|
| Volume | 337m³ |
| Thermal fabric area | 446 m² |
| Roof description | Refurbished: fully filled I beams over old roof |
| Roof U-value | 0.08 W/m² K |
| Walls description | External insulation approach. Some very minor areas with internal insulation. |
| Walls U-value | 0.12 W/m² K |
| Party walls description | Party wall insulated by injecting foam into 25 - 40 mm variable gap between house gable wall and wall of adjoining house. |
| Party walls U-value | 0.39 W/m² K |
| Floor description | new extension floor |
| Floor U-value | 0.13 W/m² K |
| Glazed doors description | Internorm, Edition range. 3g with insulated frame. Not PH certified, rather 'passivhaus suitable' approach used here. |
| Glazed doors U-value | 0.87 W/m² K uninstalled |
| Opaque doors description | N/A |
| Opaque doors U-value | - - |
| Windows description | A range of sizes to fit existing openings and in new extension. U values range from 0.87 to 1.15 (average 0.98), with a glazed fraction per window/door ranging from 39% to 71%. Glazing area 18 m2 of total window and frame area of 29 m2. |
| Windows U-value | 0.98 W/m² K uninstalled |
| Windows energy transmittance (G-value) | 0.5 % |
| Windows light transmittance | - |
| Rooflights description | Fakro triple Glazed |
| Rooflights light transmittance | 0.52% |
| Rooflights U-value | 1.49 W/m² K |
Grove Cottage : Download Files
2012_UKPHAwards_GROVE_COTTAGE_v_2.pdf (2.54 MB) CarbonLitePassivhausRefurb_GBMfinal_Rev1.pdf (939.35 KB) EnerPHit_certificate.pdf (73.87 KB) IPH_Conference_2012_How_can_EnerPHit_inform_the_UK_Green_Deal.pdf (7.33 MB) Portfield_Street_Commissioning_report.pdf (77.67 KB) Retest_57_Portfield_St_Repeat_Air_Permeability_Test_Report_-_July.pdf (200.5 KB) SMills_RetroPHit_-_Grove_Cottage_Bullets_For_Release_1.pdf (3.11 MB) Switching_from_British_Gas_to_Co-operative_Energy.pdf (14.46 KB)