UWE 900-bed student accommodation nears completion

The SAP3 project at the University of the West of England (UWE) Frenchay campus comprises three six-storey blocks of student accommodation targeting Passivhaus. A further phase (SAP5) is in the pipeline, which will provide an additional 421 new student residences, delivering an overall total of 1321 Passivhaus student rooms on the campus.

Passivhaus was selected for the project as part of UWE's target to be Net Zero by 2030. Passivhaus was seen to offer the best route to net zero and elimination of fossil fuels, thanks to its avoidance of the performance gap. The comfort criteria of Passivhaus, with health and wellbeing at its heart, has been another driver for the project to target the Passivhaus standard.

During the early design stages, the design team put a lot of effort into achieving energy efficiency through good form factor. This also had to be balanced with delivering an aesthetically successful design. The resulting design achieved a good form factor for the accommodation blocks, contributing to their overall building performance.

SAP3 Form Factor. Image credit: Stride Treglown

Key stats

Construction: Concrete and SFS infill
Form: 3 x 6-storey blocks
Number of beds: 900
TFA: 21,462m² (Block 1: 7,961m², Block 2: 8,529m², Block 3: 4,972m²)
Build start date: 2021
Completed: Aiming for 2024
Certified: Targeting Passivhaus

SAP3 UWE student accommodation. Image credit: VINCI construction

Addressing the performance gap is critical to UWE’s carbon goals. While other industry standards fall short in this area, Passivhaus shines. Certifiers visit the site every month, running tests to ensure the building fabric performs as intended. Any divergence from your initial design could see you lose your certification—putting further pressure on construction to proceed exactly as planned. While the process can be stressful, the result is worth it: a building that meets its promise, performing with minimal energy use and low operating costs, long into the future.

Tomasz Jemiol, Project Architect and Certified Passivhaus Designer, Stride Treglown

Construction

The project team opted for typical construction methodologies for a building of this size but aimed to find a simple envelope solution that could achieve the airtightness standards required by Passivhaus. The three blocks of the SAP3 project have been built using flat slab in-situ concrete frame with SFS lightweight steel wall infill. The airtightness line was designed to be located on the external face of the building structure.

SAP3 student accommodation for UWE. Image credit: VINCI cionstruction

Window design has been crucial to the project's success. The project team worked to balance heat loss, solar gains, natural ventilation, daylight, the views out, and buildability. After dozens of iterations, the project team found a single optimised window type for most of the 900 bedrooms, to work with every orientation, successfully addressing each challenge through one solution. The windows are designed with a fixed rainscreen cladding, enabling natural ventilation and shading for purge ventilation and to prevent overheating.

SAP2 window detail. Image credit: Stride Treglown

U-values

Floor: 0.13 W/m²K

Cassette value

Wall: 0.18 W/m²K

Roof: 0.16 W/m²K

Windows & doors: 0.93 W/m²K

Includes installation thermal bridges

The experience and expertise we have built up by delivering this project allows us to push the Passivhaus ‘boundaries’ in certain aspects, to maximise the quality of the architecture. We now know where we can push the boundaries and push the Passivhaus ‘golden rules’ to achieve a beautiful building that also performs its critical functions.

Tomasz Jemiol, Project Architect and Certified Passivhaus Designer, Stride Treglown

Building performance

Designed energy performance

	Block 1	Block 2	Block 3
Airtightness n₅₀ (≤ 0.6ACH @ 50 Pa) - Targeted	0.33 @ 50 Pa	0.31 @ 50 Pa	0.31 @ 50 Pa
Space Heating Demand (≤ 15 kWh/m².a)	16.1 kWh/m².a	12.9 kWh/m².a	13 kWh/m².a
Heating Load (≤ 10 W/m²)	9 W/m²	8 W/m²	8 W/m²
Primary Energy Renewable (PER) Demand (≤ 60 kWh/m².a*)	87 kWh/m².a	83 kWh/m².a	82 kWh/m².a
Primary Energy Renewable Generation	32 kWh/m².a	38 kWh/m².a	41 kWh/m².a
Overheating % (% hours>25degC)	2%	2%	2%

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

Services

The mechanical services for the project include:

Heating supplied by direct electric radiators with smart controls
Hot water provided by air source heat pump systems
Ventilation delivered through centralised MVHR systems for bedrooms and kitchens,
Some energy generation provided on site by solar PV panels on the roof

Lessons learned

The project team has already shared their thoughts on what they might do differently on future projects.

The construction method was the one that best suited the team in terms of procurement and ease (especially during supply chain difficulties during the pandemic) but the team have flagged that they might choose a different method for future projects.
The team has suggested that in future projects centralised MVHR system for bedrooms and kitchens might be substituted for a combination of centralised MVHR (bedrooms and circulation) with heat pumps for air heating AND local demand-controlled MVHR in kitchen, living, dining areas, and social spaces.
The future airtightness strategy employed might switch from liquid applied airtightness membrane to the use of sheet membrane in the future (or its omission through finding other solutions).
The hot water strategy would be changed for future projects from using ASHP for hot water to use of direct electric hot water (requiring no storage) and wastewater heat recovery (WWHR).

Key team

Architect: Stride Treglown
Passivhaus Consultant: QODA Consulting
Contractor: VINCI UK
Structural engineer: Curtins
M&E consultant: Amber Management
Quantity surveyor: Turner & Townsend
Project management: JLL
Passivhaus Certifier: Etude

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Check out other similar Passivhaus campuses below. From nurseries to universities – Discover why more educational buildings are adopting Passivhaus in our Passivhaus for Educational Buildings campaign. The business case is clear in our Passivhaus Benefits Guide.