| Planned occupancy | There are currently 4 occupants, 3 Adults and a child. The property is occupied for most of the day and one of the occupants works night shift. |
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| Space heating strategy | Space heating from air source heat pump with Thermaskirt heating distribution. Controls from weather compensator and time and temperature zone control. |
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| Water heating strategy | Water heating from air source heatpump feeding 210l thermal store with 50mm insulation and electric immersion back up. |
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| Fuel strategy | Mains electricity and electricity generated from PV. |
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| Renewable energy strategy | 2 kWp photovoltaic panel array orientated South. |
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| Passive Solar strategy | House is orientated due South. |
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| Space cooling strategy | Natural ventilation for most of the cooling season. MVHR unit has an automatic summer bypass valve to prevent exit air from the dwelling heating fresh incoming air during hot periods. This function is desirable during summer nights when outside air temperature is cooler than inside air temperature, therefore providing a cooling function. |
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| Daylighting strategy | Existing kitchen achieves an average daylight factor of at least 2%. The living room, dining room and study achieve average daylight factor of at least 1.5%. |
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| Ventilation strategy | MVHR and openable windows for summer ventilation. |
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| Airtightness strategy | Through extensive experience in Air testing we initially identified the key areas that contribute to poor air permeability tests results Our approach relies on communicating the details required to those on site who will implement them. The concrete floor is sealed to the wall to the entire perimeter. Plasterboard ceiling taped to wall, all joints in plasterboard taped. Penetrations in plasterboard to be mastic sealed. Plaster finish to walls to cover sealed floor/wall and ceiling wall/junctions. Reveals where thermal laminate board is to be installed to receive continuous strip of sealant, window board fixed on layer of compressible regupol to create air tight seal. Timloc insulated, air sealed loft hatch. External doors to Air Permeability standard in BS 6375: 1-2004 All windows and doors to receive continuous mastic seal to frame. All penetrations in denoted in elements above to be mastic sealed. |
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| Strategy for minimising thermal bridges | Careful detailing and consideration in section, plan and 3 dimensions ensures we achieve an excellent Y-value. A continuous thermal envelope is implemented and aided by the use of the external insulation system. External wall insulation extends below ground level to minimise the lateral thermal transmission. At roof level the external wall insulation extends into the eaves and wraps the head of the pre-cast concrete panel to maintain continuity with the roof insulation. Windows and doors are thermally broken and reveals and heads provide a secondary thermal barrier in the form of thermal laminate board. The existing concrete floor insulated with Specetherm is the only separated element in the otherwise continuous thermal envelope. |
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| Modelling strategy | The method of assessment used to develop the performance figures is SAP 2005 and the TSB extension sheet. The design process has used Dynamic Simulation Modelling (DSM), which is a more flexible design tool and allows for on going design improvements and management of building use. The DSM modelling has also allowed a comprehensive comparative analysis, reflecting the profile assigned within SAP and also the actual expected usage profile and temperature set points agreed with the tenant. This analysis should provide a close approximation of the actual energy use monitored by EST following the implementation of the improvements. |
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| Insulation strategy | External walls to receive NBT Pavatex Diffutherm a 95% recycled product achieving a u-value of 0.18 W/mK Roof to receive 300mm Thermafleece a natural, sustainable product achieving a u-value of 0.13W/mK. Ground floor solid slab topped with 10mm Spacetherm, unrivalled in its thermal conductivity. Its application combined with Fermacell protection board ensures a good thermal resistance with minimal disruption. |
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| Other relevant retrofit strategies | The design approach has been to benchmark, improve the fabric using appropriate materials and measures, reduce the energy load and provide heat and energy from appropriate technologies. Other considerations have included specific issues with house construction, setting, type, applicability/repeatability, planning & building regulation requirements and aesthetics. Briefing from the tenant and house provider has been integrated in this process. |
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| Contextual information | The existing pre-cast concrete panel construction and orientation led us to a solar strategy which utilises the inherent thermal mass of the internal walls. The fabric solution was detailed to ensure there is no de-bonding of the concrete's ability to absorb and radiate heat contributing to internal temperature regulation and a comfortable environment for the tenant. Careful consideration was given to summer and winter solar azimuths that helped us determine reveal depths ant the use of external shading devices. The already existing external render allowed us to utilise a higher performing external insulated render system with minimal visual impact. The orientation provided a platform for solar technologies in the form of PV. |
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