Communal Heating Options Appraisal for Bristol & Anchor Almshouse

Project

Bristol & Anchor Almshouse is a charity focused on reducing social isolation and connecting communities within the city of Bristol. It operates a community centre, The Beehive Centre, as well as a collection of almshouse cottages that accommodate older people in need of safe and secure housing.

The cottages were served with electric space heating, which is costly to run. Meanwhile, the Beehive Centre was heated with gas space heating that was approaching the end of its serviceable lifespan.

All heating and hot water bills are paid for by the charity, which wanted to explore different options for replacing the existing heating arrangements.

We modelled the existing heating and domestic hot water consumption using energy bills, SAP modelling and CIBSE Guide F Energy benchmarks to provide a ‘base case’ of total annual energy consumption, fuel cost and carbon dioxide emissions.

We then forecast the energy consumption, CO2 emissions, fuel costs and capital costs for installation of each of the following four scenarios:

• Mains gas for the Beehive Centre and cottages
• Mains gas for the cottages only
• Biomass for the Beehive Centre and cottages
• Biomass for the cottages only.

Finally, we calculated the total cost savings over a 20-year period and provided a simple payback calculation.

Services

Impacts

• Based on the results of each scenario, the option which represented the smallest investment, was to install a new mains gas communal boiler for the cottages only. This also provided the shortest payback.
• Better fuel cost savings at a similar payback could be achieved by including the Beehive Centre in the upgrade.
• The best CO2 emissions savings were achieved by the biomass heating systems. However, higher biomass fuel, maintenance and capital costs lead to longer payback periods.

Bristol & Anchor Almshouse decided that for simplicity and ease of ongoing maintenance it would keep the heating systems for the cottages and the Beehive Centre separate.

Following our findings, the charity chose the option that represented the smallest capital investment and quickest pay back, which was to install a new communal gas boiler for the cottages only.

In addition, we were able to provide a small amount of Energy Company Obligation funding towards the installation of the new boiler, which further reduced the capital cost of the project for the charity.