Creative cafe claims UK Passivhaus first

The first Passivhaus-certified Art Cafe in the UK, Goldfinch Create & Play includes a purpose-built newbuild studio and cafe, providing a beautiful and comfortable space for children and adults to be creative. If you're in the Bristol area, stop in for some coffee and healthy treats, join an art class, and experience Passivhaus comfort first hand.

Delivering an inspiring, comfortable, and environmentally sustainable space for the community to gather is core to the mission of Goldfinch and a driving factor in pursuing a Passivhaus certified building.

The benefits of Passivhaus are hugely important to reduce carbon emissions, 25% of the UK’s greenhouse gases come from the built environment, the construction and use of buildings. The Goldfinch building is so well insulated, has triple glazed windows and leaks over 15 times less air – and therefore heat – than the average building, meaning it only needs a small 7kW roof-mounted air-source heat pump to meet the heating, cooling and hot water needs.

Mark Finney, Architect, SEB & FIN

Key stats

Construction: Timber frame
TFA: 150 m²
Build start date: 2022
Completed: 2023
Certified: Passivhaus, 2023

Goldfinch Create & Play. Image credit: Alan Russell, Zed Photo

We wanted Goldfinch to be as good for the environment as it is for our community of children and parents.

Nicole Strong, Urban Designer & Client

The project brief was to create a practical studio space for running creative courses for children (and adults), and a complementary family café, for up to 60 people. The project involved the demolition of a derelict single-storey building, and replacement with the two-storey café and creative space

Construction

The building is timber-framed, full-filled with recycled cellulose insulation, with an additional internal layer of wood fibre insulation. Timber aluminium-clad triple-glazed windows have been specified. Proving that you can open the windows in a Passivhaus, the ground floor sliding windows allow the café to open onto the street in warmer weather. The roof light windows have been designed to provide purge ventilation during the summer.

The ground floor build involved the installation of a new super-insulated raft foundation system. The timber frame superstructure was built on top of this, which was constructed using timber I-joists.

Goldfinch Create & Play under construction

A single air source heat pump is enough to supply the building's heating and hot water. 21 solar panels and a 7kW battery offset much of the grid electricity required to run the building.

Embodied carbon

The project team aimed to minimise embodied carbon specifying natural building materials, such as timber frame, recycled newspaper insulation and wood fibre insulation.

450 kgCO2e/m2 GIA for RICS life cycle stages A1 through C5, but excluding operational energy and water use (B6 & B7).
A1-A5 (construction only) = 353 kgCO2e/m2 GIA, excluding biogenic storage.
A1-A5 (construction only) = 190 kgCO2e/m2 GIA, including biogenic storage.

Calculated using OneClickLCA.

The project achieved 49% embodied carbon savings from building in timber over steel. Biogenic carbon storage enhances the building's embodied carbon by 24%. The graph, below, shows the impact of biogenic storage on the whole life carbon of the building. The purple bar shows how the whole life carbon footprint reduces when considering biogenic sequestration.

Overall U-values

Floor: 0.207 W/m²K

Deep concrete raft slab, as per structural engineer’s specification; 100mm perimeter insulation upstand (vertically around perimeter of the slab), with the top of the insulation level with the top of the floor screed; 150mm grade EPS insulation; Radon membrane with fully taped seams. .

Wall: 0.115 W/m²K

I-Joist construction fully filled with recycled cellulose fibre insulation with wood fibre insulation board mechanically fixed to the timber frame, finished with external render system

Roof: 0.105 W/m²K

Timber frame warm roof system including 200mm PIR insulation.

Building performance

Designed energy performance

Airtightness n₅₀ (≤ 0.6ACH @ 50 Pa)

0.43 @ 50 Pa

Space Heating Demand (≤ 15 kWh/m².a)

6.0 kWh/m².a

Heating Load (≤ 10 W/m²)

8 W/m²

Primary Energy Renewable (PER) Demand (≤ 60 kWh/m².a*)

67 kWh/m².a

Overheating %

0% over 25C

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

Goldfinch Create & Play. Image credit: Alan Russell, Zed Photo

Challenges

The number of people visiting Goldfinch and using the space will vary greatly depending on the time and day, so we put a lot of consideration into ventilation design to promote healthy internal air quality and prevent overheating. There are two MVHR units (one on each floor), and carefully designed opening windows and roof lights.

Kit Knowles, Ecospheric

The main challenge to this build was not related to it being Passivhaus, but to its location. As the site was on a busy high street all materials had to be dropped of on the road and brought into the site by hand. The installation of the 6 metre wide triple glazed sliding doors, involved the closure of the road on a Sunday and setting a crane up in the middle of the road and then carefully lowering the sliding doors between the gap in the scaffolding and the new building.

In addition, early on in the design process, the project team realised that due to the close proximity of the neighbours rear boundary wall, the construction method would need to be adapated. An innovative panelised timber frame system was built on site, so the panels were completely finished and no access was needed to finish this section of the building.

Lessons learned

Goldfinch Create & Play

This project offers a useful template of what’s possible for small-scale retail, hospitality, community and educational spaces. The timber frame design and detailing could be replicated easily and is applicable to both commercial and domestic properties alike. The specification of natural, low embodied carbon building materials means that in addition to achieving Passivhaus certification, the project also achieved the RIBA 2030 Climate Challenge target metrics for non-domestic (new build schools) embodied carbon of < 540 kgCO2e/m2.”