Passivhaus & Secondary Schools: The UKs First Passivhaus - - PowerPoint PPT Presentation
Passivhaus & Secondary Schools: The UKs First Passivhaus Secondary School, Sutton Christian Dimbleby - Associate; Architect and Chartered Engineer, Architype NS3 - New Sutton Secondary School The UKs First Passivhaus Secondary
The UK’s First Passivhaus Secondary School, Sutton
Christian Dimbleby - Associate; Architect and Chartered Engineer, Architype
> Key Project Details > Massivhaus (Large Scale Passivhaus) > Why Passivhaus? > NS3 Design Strategies > Getting it Right on Site
The UK’s First Passivhaus Secondary School, Sutton
View of the external dining area from East
Client: London Borough of Sutton Contractor: Willmott Dixon End user: Harris Academy GIA: 10,625m2 1,275 pupils: Six form entry & 6th form Context: Existing Sutton hospital site; First component
Approach to Sutton Secondary School from North-West Corner
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Architype’s Experience
Oak Meadow 2FE Primary School 2011 Wilkinson 2FE Primary School 2014 Chester Balmore 54 Residential Units 2014 Agar Grove - Phase 1a 38 Residential Units 2018 Hereford Archive Archive 2015 The Enterprise Centre University Building 2015 Bicester Eco Business Centre - Offices 2018 Christ Church Central Church Not realised
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Closing the Performance Gap
Comfort & Wellbeing Future proof
30 60 90 120 Heating kWh/m2.a Elec kWh/m2.a Total kWh/m2.a Total PE, kWh/m2.a
Predicted Actual
The UEA The Enterprise Centre 1st year predicted vs actual consumption
KEEN research project - Comparing Air Quality:
Building User Survey (BUS) results:
Monitoring in use energy consumption
Traditional House ‘Smart’ House Passive House
Although some elements are more expensive, passivhaus gets rid of the need for expensive add-on technology to make the building function
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night-purge free cooling
> 15 kWh/m2.a thermal energy demand > 10 W/m2 maximum heating demand > PHI have granted exception to the 120 kWh/m2.a Primary Energy (all Energy consumption) but to be as minimal as possible > 0.6 ACH airtightness > >10% overheating > Meet thermal comfort requirements
NS3 Passivhaus Planning Package verification shows:
> Contrasting site contexts > Restrictions on heights & massing > Proximity to neighbouring properties > Mature trees, changes in levels, issues with highways > Uncertainty of development to the Cancer Hub to the south of the site
1
2 3 > Orientation and form of the building working together to optimise solar gain and improve day lighting > Control of glazing to face north-south to minimise
> Reduce overshadowing of building and playground
Relationship between surface area and volume of building has a major impact
East & West Facade > Recessed glazing > Vertical Fins on mullion lines North Facade > Recessed glazing East & West Facade > Recess glazing > 1.5m horizontal brise-soleil
Monthly Method Heat Balance - kWh/(m2.yr) Losses Gains Windows 15.6 31% Roof 4.5 9% Floor 7.3 15% Wall 8.2 16% Thermal Bridges 1.2 2% Infiltration 4.9 10% Ventilation 8.6 17% Solar 12.4 25% Internal 23.1 46% Heating 15.0 30% Totals 50.5 50.5 KWh/m2.yr
15 30 45 60
Losses Gains
Heating 15 Internal 23 Solar 12 Ventilation 9
Infiltration 5
Thermal Bridges 1 Wall 8
Floor 7
Roof 5
Windows 16
> Optimise window design and specification to be approximately neutral > Detailed calculations for equipment and occupants to determine exact internal heat gain > Optimise external fabric to match internal gains to minimise heating system
New Sutton Secondary School Heat Balance
Passivhaus fabric strategy
5 4 3 2 1
1. Continuous insulation without thermal bridges or cavities/gaps <0.15W/m2.K 2. Continuous airtight layer impermeable to air movement 3. Continuous windproof layer to prevent wind purge of the insulation 4. Separate services layer to prevent future impact on the airtight layer 5. Weather-proof cladding
Allow time in the programme to: > Detail every junction / penetration for airtightness > Coordinate with MEP, FF&E and end user client to ensure appliances are as low energy as possible
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> Picking the right contractor > Training the team > Pre-construction planning - workshops > Passivhaus Champion (on site quality control) > Run any possible change through the PH designer to make sure that their is no Passivhaus impact
Fundamentals
> Off site manufacture has many benefits, one of which is precision, which helps the quality standards of Passivhaus. > Another option utilised on Sutton Secondary School was a flying factory on site to manufacture all the timber components Precise design
> Test - do early stage mock-ups off site > Test - review first installation to check for quality and performance > Test again - larger scale sectional air-tests Testing
> Raw internal finish - exposed CLT & concrete soffits and walls > Natural materials - Douglas fir timber & copper cladding > Robust materials - Aluminium/timber composite triple glazed windows and brick cladding Simple Materials Palette