Gentoo Retrofit Bid 2

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as PDF Refurbishment of a pair of solid wall construction semi-detached units using passivhaus techniques

Retrofit for the future ZA527V
Images Graphs Figures Description Strategies Building

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CO2 emissionsPrimary energy requirement
Energy target
Retrofit for the Future

Energy and fuel use

Fuel use by type
Primary energy requirement
CO2 emissions
Renewables

Measured data from renewable generation is not yet available.

Fuel use

 Pre-developmentForecastMeasured
Electricity use 2190 kWh/yr 1215 kWh/yr -
Natural gas use49702 kWh/yr 4157 kWh/yr -
Oil use- - -
LPG use- - -
Wood use- - -
Other Fuel - - -
 Pre-developmentForecastMeasured
Primary energy requirement 803 kWh/m².yr 100 kWh/m².yr -
Annual CO₂ emissions 148 kg CO₂/m².yr 20 kg CO₂/m².yr -
Annual space heat demand - 39 kWh/m².yr -

Renewable energy

Electricity generationForecastMeasured
Renewables Technology--
Other Renewables Tech--
Electricity consumed by generation --
Primary energy requirement
offset by renewable generation		100 kWh/m².yr -
Annual CO₂ emissions
offset by renewable generation		20 kg CO₂/m².yr -

Calculation and targets

Whole house energy calculation method PHPP
Other whole house calculation method-
Energy target Retrofit for the Future
Other energy targets-
Forecast heating load 15 W/m² demand

Airtightness

 DateResult
Pre-development air permeability test--
Final air permeability test--

Project description

StageUnder construction
Start date05 April 2010
Occupation date18 May 2010
Location Sunderland Tyne & Wear  England
Build typeRefurbishment
Building sectorPublic Residential
Property typeSemi-Detached
Construction typeOther
Other construction typeWimpey No Fines Construction: solid reinforced concrete
Party wall constructioncavity wall
Floor area 78 m²
Floor area calculation method Treated Floor Area (PHPP)
Building certification

Project Team

OrganisationGentoo Sunderland Ltd
Project lead personDevereux Architects
Landlord or ClientGentoo Sunderland
ArchitectDevereux Architects
Mechanical & electrical consultant Alan Clarke (Mech) & Gentoo Construction (Arch)
Energy consultantAlan Clarke
Structural engineerGentoo Construction
Quantity surveyorGentoo Construction
Consultant
ContractorGentoo Construction

Design strategies

Planned occupancyAs at present:
Space heating strategyGas condensing boiler to use existing radiator central heating system. Room compensated boiler flow temperature control. A-rated low energy circulation pump.
Water heating strategySolar thermal using roof-integrated flat panels, twin coil cylinder with 100mm insulation located in warm loft. Gas boiler back up, no immersion heater.
Fuel strategyExisting supplies: mains gas and electricity
Renewable energy strategyNone
Passive Solar strategyRetaining existing opening sizes. Full glazing to south facing kitchen door.
Space cooling strategyThanks to modest glazed areas PHPP shows that natural ventilation will be sufficient. Thermal mass retained inside the building will aid night cooling if required.
Daylighting strategyExisting window openings used, with increased glass area and double glazing rather than triple.
Ventilation strategyWinter ventilation using mechanical heat recovery ventilation. Automatic relative humidity control. MVHR unit located in kitchen for ease of access for maintenance. Opening windows for use in summer.
Airtightness strategy Roof air barrier membrane sealed to parge coat of render on masonry wall. Windows taped to wall and fitted with flexible expanding foam. Solid ground floor. Rubber seals around pipe, flue and cable penetrations (eg pro clima grummet). Party wall enclosed by treatment of both semi-detached houses together.
Strategy for minimising thermal bridges Thermal bridge free approach: Roof insulation over rafters to enable full thickness to go over eaves and gable and join external wall insulation. Windows fixed to external surface of wall so within the external insulation layer. Wall insulation extends below ground (without base rail) down to foundations to minimise floor heat loss. This has been modelled using Therm.
Modelling strategyPHPP whole house energy and summer overheating Therm for thermal bridging
Insulation strategyExternal "overcoat": Over rafters to raise roof, using glass fibre, U=0.11 External wall insulation using graphite EPS, U=0.13 No floor insulation as tenants remain in situ. Insulation provided by carpet and underlay, and by below ground wall insulation. Windows use highly insulating PVC frame (U=0.8) and high performance double glazing (U=1.1) with stainless spacers.
Other relevant retrofit strategiesTenants remain in the houses throughout. Two semi detached houses are retrofitted together to eliminate problems at party wall and enable removal of chimney.
Contextual informationTreating two houses together has limited the budget and forced a focus on cost-effective measures. Solid concrete walls mean external wall insulation offers high cost benefit. Appearance not changed greatly by external insulation.

Building services

OccupancyNULL
Space heatingNULL
Hot waterNULL
VentilationNULL
ControlsNULL
CookingNULL
LightingNULL
AppliancesNULL
Renewable energy generation systemNULL
Strategy for minimising thermal bridgesNULL

Building construction

Storeys 0
Volume -
Thermal fabric area -
Roof description NULL
Roof U-value 0.00 W/m² K
Walls description NULL
Walls U-value 0.00 W/m² K
Party walls description NULL
Party walls U-value 0.00 W/m² K
Floor description NULL
Floor U-value 0.00 W/m² K
Glazed doors description NULL
Glazed doors U-value 0.00 W/m² K -
Opaque doors description NULL
Opaque doors U-value 0.00 W/m² K -
Windows description NULL
Windows U-value 0.00 W/m² K -
Windows energy transmittance (G-value) -
Windows light transmittance -
Rooflights description NULL
Rooflights light transmittance -
Rooflights U-value 0.00 W/m² K