Wolverhampton Passivhaus schools leading the pack

A new Passivhaus school in Wolverhampton has just been certified - the latest project in the area's pioneering Passivhaus educational buildings. The Wednesfield Technology Primary School is now the fourth Passivhaus school project for City of Wolverhampton Council.

The school was built as a replacement for the existing and derelict Edward the Elder school. The Passivhaus standard was chosen to meet the City of Wolverhampton Council’s objectives to improve air quality in schools and reduce energy usage. The school was also designed in conjunction with the Shireland Collegiate Multi Academy Trust (SCMAT) design principles, which required the specification of a range of sustainable, low embodied carbon materials and guaranteed building performance.

City of Wolverhampton Council has been a Passivhaus pioneer, introducing one of the first Passivhaus school projects in the UK in 2011 with Oakmeadow Primary School. The Wednesfield project is now the Council's fourth Passivhaus school. The project was designed by PHT members Corstorphine & Wright with PHT member Delta Q as Passivhaus Consultant. The project was certified by PHT Patron WARM.

Key stats

Construction: Timber frame, with brick facade
Number of pupils: 450
TFA: 1875 m²
Form factor: 2.24
Build start date: 2023
Completed: 2024
Certified: Passivhaus, 2025

Wednesfield Primary School. Image credit: C+W Architects & Photographer Daniel Shearing

We are thrilled to see the completion of Wednesfield Technology Primary School, a beacon of sustainable and innovative education within the Black Country. This Passivhaus-certified facility represents a significant step forward in our commitment to providing state-of-the-art learning environments. The advanced energy efficiency and superior air quality achieved in this building align perfectly with our goal to foster a healthy and stimulating atmosphere for our students.

Sir Mark Grundy, CEO, Shireland Collegiate Academy Trust

Wednesfield Technology Primary School. Image credit: Delta Q

Construction

The positioning of the school was dictated by the need to retain most of the trees on the site as well as the need to include space for a sports pitch and hard play area. The replacement school was designed as a single rectangular two-storey block, with a smaller, one-storey wing joining the main building at right angles, all constructed in Larsen Truss timber frame. The architectural design also referenced the local residential vernacular of red-brick and rendered facades. The building is brick clad – for its entire height on the wall facing the road, with render on the upper parts of the other walls. Brick cladding was a requirement from the planners, echoing the brick of the school that had stood on the site.

A prefabricated twin-stud timber frame Larsen Truss system for external walling was used.The system consisted of twin walls of timber frames braced together, boarded with MDF internally, and RCM (Rainscreen Cladding Material) externally, then infilled with 380mm of mineral insulation, some in the factory and some on site. The project team worked closely with the timber frame manufacturers to develop detailing to minimise thermal bridging and ensure a consistent airtightness barrier. To ensure an airtight line, the timber panels have an adhesive vapour permeable membrane applied to the inside face for site taping.

It's been an incredibly rewarding project to be part of. The site team was receptive to our guidance and adapted well to the precision and discipline required to meet the Passivhaus standard. The finished building stands as a true testament to the hard work, collaboration, and expertise of both the design and site teams.

Tristan King, Passivhaus Consultant, Delta Q

Embodied carbon

Most of the demolition waste has been used to level up the site and some of the bricks were retained. The stone from the former demolished school has been carefully preserved and will be repositioned adjacent to the entrance of the new school.

U-values

Roof: 0.102 W/m²K

Timber, PIR insulation

Wednesfield Technology Primary School. Timber frame construction. Image credit: Delta Q

Wall: 0.122 W/m²K

Timber frame with mineral wool insulation.

Floor: 0.131 W/m²K

EPS insulation on concrete raft foundation

This is one of the most challenging projects I have had. It’s certainly the most meticulous I’ve ever been on.

Kevin Miners, Project Manager, Tilbury Douglas

Building performance

Designed energy performance

Airtightness n₅₀ (≤ 0.6ACH @ 50 Pa)

0.48 @ 50 Pa

Space Heating Demand (≤ 15 kWh/m².a)

13 kWh/m².a

Heating Load (≤ 10 W/m²)

9 W/m²

Primary Energy Demand (≤ 85 kWh/m².a)

78 kWh/m².a

*+/-15 kWh/m².a allowance if offset by energy generation. See Passivhaus criteria.

Services

Heating: The school is heated using a small gas boiler. The heat emitters are predominantly moderately-sized radiators in each room with radiant panels in the hall and kitchen.
Ventilation: Ventilation is provided by a MVHR system, with the ventilation plant located on the flat roof.
Summer comfort: The summer comfort approach involves mechanical night ventilation, window opening, and minimal external shading. Thermal modelling was used to refine the control strategy and calculate additional power requirements, to ensure the Passivhaus certification criteria were met. During hot periods in the summer, the mechanical ventilation system can run at night without heat recovery to cool both the spaces and the building fabric which reduces internal temperatures during occupied school hours.
Hot water: Hot water was delivered to the kitchen from the boiler via heat interface units while the hot water to toilets and classrooms was supplied via point of use water heaters, to keep distribution losses down

Challenges & lessons learned

Wednesfield Primary School. Image credit: C+W Architects & Photographer Daniel Shearing

Attention to detail: The insulated floor slab required meticulous attention to detail. The building sits on a raft foundation, with a double layer of insulation under the slab. The joints of the insulation are staggered, to prevent heat loss, and the insulation extends all the way under the upstand and around the edge of the slab. All the pieces of insulation were hot-wire cut so that they were dimensioned exactly to the millimetre. Each joint has to be individually assessed on site, with evidence – including photos – supplied to the Passivhaus designer and certifier.
Minimising thermal bridging with timber frame: The need to prevent cold bridging and achieve airtightness at junctions caused a few extra issues when it came to assembling the timber frame. The panels are more usually used for housing projects and the way that adjacent panels are normally joined to each other was not good enough for the school Passivhaus requirements. To overcome this challenge, the timber frame supplier delivered panels that had short unfinished sections at either end, so that the insulation and boards could be installed on site, ensuring there was no cold bridging.
Simplifying construction: Having the timber frame contractor as a single point of responsibility for achieving the airtightness requirements in the wall, roof and floor junctions on site allowed for more efficient development and construction of details as the interface junctions were not reliant on multiple trades and could be developed quicker as the lines of communication was reduced.
Passivhaus champion: The contractor ensured that several members of the site team had completed the Passivhaus tradesperson course and appointed a dedicated Passivhaus champion to oversee the Passivhaus aspects of the build. The Passivhaus Consultant set up a training and benchmarking system with the Passivhaus Champion to ensure confidence in obtaining Passivhaus certification.
Timescales: The airtightness detailing meant that it took longer for the contractors to get the building watertight than they had expected. Taking the extra time paid off though in the project's excellent airtightness results.
Handover: A clear and accessible building guide has been developed by the Passivhaus Consultants to ensure ease of use for the school’s operators and that the building operates efficiently and continues to meet Passivhaus performance standards long after the project’s completion.. Delta Q has also been actively involved in the handover process, providing ongoing support to ensure the operators fully understand the design intent, key operational procedures, and maintenance requirements.

Wednesfield Primary School. Image credit: C+W Architects & Photographer Daniel Shearing

Architect’s view

This was a great project to be a part of. Working with a dedicated and passionate client and design team allowed us to design and deliver a scheme of such high sustainable calibre for the children of the area. In partnership with Delta-Q we were able to develop and achieve a robust airtightness strategy surpassing the stringent requirements of Passivhaus, providing a flagship school and template for Shireland Collegiate Academy Trust’

James Edwards, Architect, Corstophine & Wright

Key team

Client: City of Wolverhampton & Department for Education
Architect: Corstorphine & Wright
Passivhaus Consultant: Delta Q
Contractor: Tilbury Douglas
Timber frame: Timber Innovations
Structural engineer: Clancy Consulting
M&E consultant: Dodd Group
Passivhaus Certifier: WARM

Many congratulations to City of Wolverhampton Council for its continued commitment to the Passivhaus standard for its school delivery programme. Its brilliant that, as one of the UK's Passivhaus pioneers, it continues to see the benefits of the Passivhaus standard for local authority buildings. Discover more projects on our Passivhaus Schools & Educational Buildings pages.