Inclusive, Low Carbon Environments

PassivHaus, which is primarily a design standard, also provides a high standard of comfort as part of its offering which is underpinned by harnessing and optimising passive energy and low-carbon methods. The standard prioritises building fabric, uses strict criteria and parameters to calculate performance, and is reliant on the design, build and operation of a scheme being aligned to achieve the performance.

The Department for Education (DfE) identified Trent View College to be part of the DfE sustainability pilot, requiring it to achieve PassivHaus standards, which in addition to providing an energy efficient building, has health and wellbeing benefits for users of SEND settings, due to the creation of an internal environment that is both comfortable and stable with clean, regulated air. Appointed by the DfE, Consultants, Cundall, formed part of the DfE Technical Advisor team working alongside the Contractor-led team to ensure that PassivHaus certification could be achieved.

The original non-PassivHaus feasibility scheme had to be revisited and optimised to enable it to fulfil the PassivHaus standard.

A direct comparison with the existing design was undertaken, to establish how it could be amended rather than fully redesigned in order to achieve PassivHaus. From the outset, Cundall implemented the criteria into the design, so that at every step the project outcomes could be tested, verified and validated against the projections.

Fundamental to the delivery of the project was the PassivHaus Planning Package (PHPP), which is used at every stage to calculate how the progression of the build is performing against the targets and as a tool to inform the developing design. PassivHaus, however, was only one set of criteria that was applied to the design; compliance with the DfE Output Specification for schools had to be achieved alongside the Trust’s school-specific brief. The design and delivery teams therefore had multiple and complex sets of restrictions and targets to meet.

As the orientation and form of the building had already been established, the optimisation of spaces and adjacencies to create more efficient distribution of energy was paramount in achieving PassivHaus criteria.

All classrooms, service rooms, and larger spaces were therefore grouped together, optimising the synergies between room typologies. While PassivHaus is a rigorous standard in any setting, the SEND environment introduced extra challenges including increased electrical loads due to the specialist equipment which is necessary for the users such as hoists, wheelchair charging and sensory equipment.  The scheme also included a hydrotherapy pool which had to have new criteria written for its inclusion to ensure it was as energy efficient as possible. The primary challenge relating to the pool was mitigating heat loss and condensation between adjacent spaces due to the high water and air temperatures required in the pool area.

Numerous building elements contributed to the success of the design, including;

• inclusion of energy efficient air source heat pumps and MVHR’s for ventilation and heating
• optimisation of glazing ratios for solar gain/control, natural ventilation and natural daylight
• maximisation of thermal-bridge free and air-tight detailing
• careful design of the overall building layout

The resultant scheme delivers an energy efficient, comfortable and affordable solution – compliant with the DfE’s Output Specification, Trust’s School Specific Brief and in line with the Department’s wider sustainability ambitions.

In the second half of the presentation, Claire Jackson from Galliford Try and Allan Smith from Morrison Construction discussed their experience as Main Contractors working with existing schools to achieve low-carbon outputs.

You can listen to the full presentation here: Inclusive Low Carbon Environments – Learning hub