Charlesworth Passivhaus Plus : 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 | - | 9000 kWh/yr | - |
|---|---|---|---|
| Natural gas use | - | - | - |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | - | 75 kWh/m².yr | - |
|---|---|---|---|
| Annual CO₂ emissions | - | 18 kg CO₂/m².yr | - |
| Annual space heat demand | - | 12.5 kWh/m².yr | - |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| PV | 12986.82 kWh/yr | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | -33 kWh/m².yr | - |
| Annual CO₂ emissions offset by renewable generation | -8 kg CO₂/m².yr | - |
Calculation and targets
| Whole house energy calculation method | PHPP |
|---|---|
| Other whole house calculation method | - |
| Energy target | PassivHaus |
| Other energy targets | Passivhaus Plus standard requires energy generation of at least 60 kWh/(ma) with a maximum 45 kWh/(ma) of renewable primary energy demand. |
| Forecast heating load | 9.2 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | - | - |
Project description
| Stage | Under construction |
|---|---|
| Start date | 30 May 2018 |
| Occupation date | 01 October 2020 |
| Location | Charlesworth Derbyshire England |
| Build type | New build |
| Building sector | Private Residential |
| Property type | Detached |
| Construction type | Other |
| Other construction type | ICF |
| Party wall construction | N/A |
| Floor area | 299.8 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |
Project Team
| Organisation | The Stewart Brothers |
|---|---|
| Project lead person | David Stewart |
| Landlord or Client | Susan Stewart |
| Architect | Russel Bridge |
| Mechanical & electrical consultant | JKN, ADM, IPH, Genesis Solutions |
| Energy consultant | DesignBuro |
| Structural engineer | Scott Hornby, ADM |
| Quantity surveyor | |
| Consultant | |
| Contractor | AWS |
Design strategies
| Planned occupancy | 2 - 6 most out to work all day, 1 mostly in all day. |
|---|---|
| Space heating strategy | UFH using Ground Source Heat Pump with MVHR |
| Water heating strategy | Heat pump with PV top up via immersion heater and Tesla batteries. |
| Fuel strategy | PV electricity & Tesla Batteries, plus mains electricity backup. |
| Renewable energy strategy | 13.86kWp PV array being installed. |
| Passive Solar strategy | Orientation due south. Window design optimised using PHPP. |
| Space cooling strategy | MVHR, solar gain modified by automated blinds linked to climate control system, automated opening rooflight for heat dump when required. Natural ventilation through core of building. |
| Daylighting strategy | Main kitchen dining and living area has full south facing glazing with automated blinds for glare control. All bedrooms and bathrooms face north with reducing glazing to north or east. Study faces north west with glazing to both elevations. Office faces due south with full glazing to south elevation and automated blinds for glare control, and limited west facing glazing. |
| Ventilation strategy | MVHR with summer bypass and integrated automation. Openable windows, automated rooflight opening for overheat control. |
| Airtightness strategy | External envelope of ICF. SIP constructed roof with airtight membrane internally sealed to ICF concrete core, protected by 50mm service void. |
| Strategy for minimising thermal bridges | Original design by passivhaus certified designer. Design development after design certification during construction guided by Passivhaus advisors, continuous external insulation envelope maintained, all penetrations (including fixings and anchors to elements external to the insulation envelope) incorporate thermal breaks and have been subjected to thermal bridge analysis. All junctions incorporated into PHPP. |
| Modelling strategy | Whole house modelling was undertaken in PHPP and included the proposed PV and heating system. |
| Insulation strategy | External insulation by ICF supplemented by Graphite EPS to achieve a U value of 0.119 for all walls. Raft foundation insulated by 300mm EPS under non load bearing areas, and 150mm under load bearing thickeners. Pitched roof SIP with external PIR insulation to a U value of 0.12 to roof. Flat roof MgO SIP with below deck spray insulation to flat roof to achieve U value of 0.012 |
| Other relevant retrofit strategies | |
| Contextual information | Obtaining planning permission was challenging, the site is sloping in 2 directions which required significant excavation but allowed for a more interesting and sympathetic design. Since space heating requirement is extremely small, the choice was centred around the most efficient method of generating domestic hot water without burning fossil fuel. Hence the use of the heat pump and PV support. The absence of a suitable R744 heat pump in the UK as a more efficient means of generating DWH is a significant disappointment, but could be retrofitted in the future as a direct swap. |
Building services
| Occupancy | |
|---|---|
| Space heating | Nibe 1155 GSHP located in basement plant room. Heat emitter via UFH. |
| Hot water | Nibe 1155 GSHP supplemented with 13.86kWp PV array supported by 2 x Tesla 2 batteries. |
| Ventilation | Zehnder Q600PH MVHR located in basement plant room fed from a Rehau ground air heat exchanger. |
| Controls | System integrated into a loxone control system. This combines the control systems from the heat pump, MVHR system, environmental sensors with the control of the internal blinds to the south elevation and the roof light for heat dump. |
| Cooking | Induction hob and electric oven |
| Lighting | 100% LED mostly with presence monitor switching. |
| Appliances | fridge, freezers, washing machine minimum A+ rating |
| Renewable energy generation system | PV arrays providing 12.84kWhr tied to 2 x Tesla powerwall batteries, providing 14kWhr storage and immersion heaters to the thermal water store |
| Strategy for minimising thermal bridges | Most designed out, those which cannot have been modelled and entered into PHPP (e.g. shek thermal breaks to steel beams, fischer Thermax bolts attaching external canopy. |
Building construction
| Storeys | 25 |
|---|---|
| Volume | - |
| Thermal fabric area | - |
| Roof description | 175mm SIP with 100mm external PUR insulation |
| Roof U-value | 0.11 W/m² K |
| Walls description | ICF:Basement 67mm EPS:203mm Waterproof reinforced concrete:67mm EPS + 130mm Neopor external insulationLower ground, Ground and walls to dormer 67mm EPS:152mm reinforced Concrete:67mm EPS + 130mm Neopor external insulation |
| Walls U-value | 0.12 W/m² K |
| Party walls description | |
| Party walls U-value | - |
| Floor description | Basement foundation slab 200mm waterproof reinforced concrete with thickeners to 350mm to load bearing areas.Supported by 300mm EPS insulation with 150mm EPS insulation to load bearing areas |
| Floor U-value | 0.10 W/m² K |
| Glazed doors description | Internorm HS330 sliding units Uw 0.77 for large span (12284mm) and 0.72 for small spans (2100mm, 3452mm - 3496mm)Averaged U value 0.75 |
| Glazed doors U-value | 0.75 W/m² K - |
| Opaque doors description | Internorm HT410 door with side light |
| Opaque doors U-value | 0.64 W/m² K uninstalled |
| Windows description | HF310 |
| Windows U-value | 0.77 W/m² K uninstalled |
| Windows energy transmittance (G-value) | 54 % |
| Windows light transmittance | - |
| Rooflights description | Lamilux 3000 x 1000 with 1000 x 1000mm opening section at top |
| Rooflights light transmittance | 69% |
| Rooflights U-value | 0.60 W/m² K |