project name grove cottage extension & refurbishment of

https://www.lowenergybuildings.org.uk/

Project name Grove CottageProject summary Extension & Refurbishment of Victorian Townhouse using Passivhausmethodology and CarbonLite guidance. Certified to the Passivhaus Institute's new EnerPHit(refurbishment) Standard. [NEW:Passivhaus Trust awards shortlisted project - presentationavailable on these pages].PHPP certification is based on 20 C, rather than the 21 C the house washeated to during 2010/11. Forecasts are based on a 'typical year' rather than the 'actual' year beingmonitored. Measured data here is from 2005/06 (before) and 2009/10 (after). Measured roomtemperatures show an average of 21 degrees centigrade during the heating season. Please notethe final air leakage as certified under EnerPHit was an N50 of 1.0 ACH. When adjusted for 2010average monthly temps.& an internal temp. of 21 C, PHPP predicted a space heat demand of36kWh/m2.a whereas 35kWh/m2.a was measured.

Project Description

Low Energy Buildings

Projected build start date 11 Jul 2008

Projected date of occupation 01 Mar 2009

Project stage Occupied

Project location Hereford, Herefordshire, England

Energy target EnerPHit

Build type Refurbishment

Project team

Design strategies


Building sector Private Residential

Property type Semi-Detached

Existing external wall construction Solid Brick

Existing external wall additional information

Existing party wall construction

Floor area 135 m²

Floor area calculation method PHPP

Building certification Passivhaus certified

Organisation Simmonds.Mills Architects

Project lead Andrew Simmonds

Client Andrew Simmonds, Lorna Pearcey

Architect Simmonds.Mills Architects

Mechanical & electrical consultant(s) Alan Clarke, Peter Warm

Energy consultant(s) David Olivier

Structural engineer Bob Johnson

Quantity surveyor None

Other consultant None

Contractor Eco-DC

Planned occupancy 2 adults and 3 children.

Space heating strategy Passive Solar + Mechanical Ventilation &Heat Recovery (MVHR) + replacement gasboiler inc. retention of existing radiators

Water heating strategy Replacement gas boiler + super insulated,solar ready hot water cylinder + all hot andcold water pipes insulated. Installedmeasures include a south facing roof areaconstructed to allow future installation of 4.5m2 of solar thermal panels to feed into HWC

Fuel strategy Natural gas (minimised use of). Biomass notconsidered as appropriate fuel due toresultant air pollution issues (particulatesetc) in a city residential area, combined withhigh capital costs associated with biomassequipment relative to low heat demandrequired.

Renewable energy generation strategy No electricity generation technologiescurrently adopted.


Passive solar strategy Passive solar gain maximised as far aspossible mainly through creation of newSouth facing windows in existing house andnew extension.

Space cooling strategy Existing house on N-S axis (main elevationsEast and West). Use of new & retention ofexisting thermal mass (blockwork /brickwork) within insulation envelope (i.e.use of external insulation). Windows -summer shading as result of window setback. MVHR has automatic summerbypass allowing automatic cooling at nightduring hot spells. More substantial rate ofnight time ventilation for cooling purposesalso possible via openable windows (goodarrangement for passive stack ventilationdesigned in).

Daylighting strategy Extensive daylighting to all rooms todisplace electric lighting. Maximisingdaylighting through careful sizing anddesign of windows and internal colourscheme (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 openablewindows if required, (good arrangement forpassive stack ventilation designed in).

Airtightness strategy Existing house: external face of existingbrick walls parged (thin layer of cementitiousmaterial used). New extension: internalplaster to blockwork walls + use of airvapour barriers in ceilings and some limitedwall areas where timber frame was requiredabove brick/blockwork.

Strategy for minimising thermal bridges Adoption of 'thermal bridge-free'construction detailing for new constructionand also in refurbishment work wherepossible.

Modelling strategy PHPP. Limited use of THERM.

Insulation strategy *Application of external insulation to solidbrick and new blockwork walls*Insulation ofexisting suspended floor*Insulation ofexisting solid floor*New floor raft foundationwith structural eps insulationbelow*Renewal of existing roof andplacement of insulation above existingrafters. New roof uses fully filled I beams.

Other relevant retrofit strategies Family remained in house during allrefurbishment and new build works.

Energy useFuel use by type (kWh/yr)

Fuel previous forecast measured

Primary energy requirement & CO2 emissions

previous forecast measured

Renewable energy (kWh/yr)

Renewables technology forecast measured

Airtightness ( m³/m².hr @ 50 Pascals )

Date oftest

Testresult

Annual space heat demand ( kWh/m².yr )

Pre-development forecast measured


Other information (constraints oropportunities influencing project design oroutcomes)

House had limited architectural detail onstreet facade: Painted brickwork. (Decayed)stone subcills to windows: (Painted) stonelintels visible above windows. An originalcarved stone plaque was mounted on thehouse wall. The subcills and lintels detailshave been recreated in the new render. Thestreet side entrance porch will be rebuilt intimber and roofed in original slates. Theplaque will be recreated, updated andmounted as before.

Electric

4300 2728 3312

Gas 24000 6724 6937

Oil

LPG

Wood

Annual CO2 emissions (kg CO2/m².yr)

55 22 25

Primary energyrequirement (kWh/m².yr)

284 108 120

-

-

Energy consumed bygeneration

Pre-development airtightness - -

Final airtightness 16 Jul 2010 0.88

Space heatdemand

- 25 35

Whole house energy calculation method PHPP

Building services

Building construction


Other energy calculation method PHPP results (EnerPHit certification file) arebased on 20 C internal temps and standrd'typical year'.

Predicted heating load 13 W/m² (demand)

Other energy target(s)

Occupancy As per stage 2

Space heating Vaillant natural gas non-system boiler with AlphaPro 2 external circulating pump etc

Hot water HWC details, insulated pipe details

Ventilation Paul etc Heat Recovery Ventilation Unit, frostprotection preheater.

Controls Set for continuous heating - wall mounted Vaillant digital control and room thermostat andweather 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 existingappliances: AEG Oko-Lavamat 74630 *dishwasher: ISE DW51 *electric tumble drier -(now junked), MVHR serviced clothes dryingcupboard. Also home office equipment; 2laptops, 2 printers, router, office lighting. Homeoffice is not separately metered.

Renewables None

Strategy for minimising thermal bridges 'Thermal bridge-free' strategy. For details - seeuploaded documents

Storeys 3

Volume 337m³

Thermal fabric area 446m²

Roof description Refurbished: fully filled I beams over old roof

Roof U-value 0.08W/m² K

Walls description External insulation approach. Some very minor areas withinternal insulation.

Walls U-value 0.12W/m² K

Party walls description Party wall insulated by injecting foam into 25 - 40 mmvariable gap between house gable wall and wall ofadjoining house.

Party walls U-value 0.39W/m² K

Floor description new extension floor


Floor U-value 0.13W/m² K

Glazed doors description Internorm, Edition range. 3g with insulated frame. Not PHcertified, rather 'passivhaus suitable' approach used here.

Glazed doors U-value 0.87W/m² K uninstalled

Opaque doors description N/A

Opaque doors U-value

Windows description A range of sizes to fit existing openings and in newextension. U values range from 0.87 to 1.15 (average0.98), with a glazed fraction per window/door rangingfrom 39% to 71%. Glazing area 18 m2 of total windowand frame area of 29 m2.

Windows U-value 0.98W/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 1.49W/m² K uninstalled

Project images


project name grove cottage extension & refurbishment of

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