GRAHAM has completed and handed over Weavers’ Hall, a 16-storey, 459-bedroom purpose-built managed student accommodation (PBMSA) on Belfast’s Dublin Road, designed and constructed to the Passivhaus standard for Queen's University Belfast. The building offers a mix of cluster apartments and studios alongside quiet study areas, communal lounges, dining spaces, laundry and reception facilities.

As Belfast's first Passivhaus-certified student residence and the largest Passivhaus student development on the island of Ireland, the project’s principal technical hurdle was delivering Passivhaus performance in a building that exceeds the 35-metre tall‑building threshold.

Passivhaus certification requires exceptional fabric and systems performance across the whole asset. Weavers’ Hall’s verified outcomes include:

- Space heating load: 9.5 W/m², below the Passivhaus threshold of 10 W/m²

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- Space heating demand: 15.0 kWh/m² per year, meeting the 15 kWh/m² limit

- Primary energy demand: 69 kWh/m² per year, within a project-specific 70 kWh/m² target reflecting high occupancy

- Airtightness: average 0.49 air changes per hour (ACH) at 50 Pascals across positive and negative pressure tests, exceeding the 0.6 ACH requirement

The airtightness result is almost 20% better than the Passivhaus limit. Achieving that consistently across 16 storeys and extensive façade interfaces demanded detailed thermal bridge modelling, comprehensive façade reviews and targeted installation workshops before construction commenced.

To realise the performance targets, the team adopted an external self-adhesive airtight membrane and treated the steel frame system (SFS) as a service zone so the continuous airtightness layer sits outside the SFS line. A semi-centralised ventilation strategy deploys individual mechanical ventilation with heat recovery (MVHR) units serving vertically stacked apartments, reducing supply and extract penetrations through the external façade.

Procured via the Pagabo Major Works Framework with early contractor involvement, the project ran cost planning, design and planning in parallel, allowing every decision to be tested through a Passivhaus lens. The scheme progressed from Stage 0 in May 2023 to breaking ground in August 2024, then reached completion and handover on 11 September 2026, equating to a build period of just over two years on site.

Weavers' Hall is fully electric with no fossil fuels. Air source heat pumps provide space heating and hot water, while switching to CEM II cement with limestone fines reduced embodied carbon by 166 tonnes of CO2 equivalent. The development is targeting a BREEAM Excellent rating.