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Passivhaus Office for PYC Group

Sustainable building specialists PYC Group are putting their principles into practice having built their own certified Passivhaus office in Welshpool, Powys. The 220m2 office building was constructed using their own timber frame system to a budget of £350,000.

21° supplied the ULTRA triple glazed timber windows and doors and Compacfoam insulation for thermal breaks at door thresholds.


The office was built in timber frame by PYC group using an I-beam system, with Warmcel recycled newspaper insulation within the timber frame.  The panels were made in the company’s adjacent factory. Timber features heavily in the internal spaces of the office  reflecting  a focus on reducing the embodied CO2 of building materials at the project.

The office achieved an airtightness of 0.5 ACH (n50) and has  a space heating need of 14 kWh/m2/year. There is no conventional central heating system in the office, with a small portable 1kW portable electric heater providing all space heating and  hot water provided by an instantaneous electric water heater and shower. Estimated space heating costs are £47 per month.

We felt that building the offices to Passivhaus standards would exemplify the work that we do. There were other major benefits including being cheap to run, comfortable and healthy for workers.

Jasper Meade, Director at PYC Group

Triple glazed windows & doors

21° ULTRA triple glazed timber windows and entrance doors.  were specified for the project. Entrance doors, French doors and inward opening tilt & turn windows (with 240mm extension cills) from the ULTRA range were supplied in RAL colour 7016. 

The windows and doors were sealed using Pro Clima airtightness tapes, delivering an overall window U value of 0.79 W/m2K

The ULTRA range was the obvious choice for us. The U-values were in line with our needs and plans for Passivhaus certification. The support from 21° was always first rate.

Rich Hibbert - Technical Manager at PYC Group


Compacfoam 200 insulation, from 21°, was used as a thermal break at the door thresholds.

Compacfoam is ideally suited for this issue. 21°s design team helped create a detail which resolved any cold bridging issues along the door openings.

Ben Meade, Director at PYC Group

More information

PYC Group Tel: 01938 500797

An in-depth case study on the project has been featured in issue 32 of Passive House+ magazine (December 2019) 

Project details

Passihaus certification

April 2019

Case study


Life changing homes