When Downs Merrifield Architects were approached in 2017 by a group called The 50+ Llandaff Group to convert a former council toilet just off Cathedral Close, Llandaff into a community facility they were intrigued. The tiny 36m2 building had two different forms of construction - solid stone wall and 1970s basic cavity wall and needed a new extension.
The brief was for: a tourist information point; accessible toilet and multiuse space for the daily activities run by the volunteers which needed to be suitable for older people. There were some obvious planning hurdles as the building was immediately next to the Bishop's Palace, in a conservation area, had bats and a requirement for an archaeological dig which took place during an extremely wet September in 2019 and uncovered a 14th Century Medieval Hall House.
The design retained the stone external walls and slate roof and provided a sympathetic single storey timber framed extension within the courtyard to the rear, with overhanging eaves to provide shelter and solar shading. Internally, consideration was needed to make the space flexible, with the group running classes as varied as Tai Chi, iPad use, painting and regular talks which might include up to 30 people. The acoustic and lighting requirements as well as thermal comfort were all very important.
The client was very keen for the building to be as environmentally sustainable as possible to keep running costs down. Using a fabric first approach, there are different internal insulation solutions to suit the different constructions, whilst keeping the walls breathable and improving the airtightness of the building. This, together with the timber frame extension has pushed the EPC rating up to an A and the building has become a demonstration retrofit project for existing homes, with information boards for the public to view and a video explaining the systems.
Downs Merrifield worked with Wye Valley and 3DE to provide the thermal modelling and environmental systems advice. The ventilation system is capable of dealing with a large variation in user numbers, with a heat exchanger which is on view above the toilet. This, together with an air source heat pump in the courtyard for the underfloor heating can be monitored remotely. There is a mixture of Photovoltaic panels and PV slates to assist with the electricity demands and a rainwater harvesting tank for the toilet.
Covid-19 obviously delayed things on site with the contractors A&N Lewis doing their best to stick within the restricted client’s £300K budget and funding arrangements, working closely throughout with the QS Owen Associates. Completion was given in October 2020 but the opening of the building was delayed because of the cautiousness of the client because of the large number of elderly users. However, it was officially opened by Baroness Ilora Finlay, a patron of the charity on 23 June 2022.
Carolyn Merrifield
Downs Merrifield Architects
