Environmentally Sustainable Housing – Old Gaol, Abingdon

At the start of 2015 the Company held preliminary discussions with a client who wanted to redevelop the Old Gaol in Abingdon into two 2-bedroom and eight 1-bedroom sustainable apartments. They wanted to build the most prestigious looking, environmentally friendly apartments that they could within their budget without losing the history of the oldest Napoleonic Gaol in the country. This would involve stripping out and making safe the existing building prior to designing energy efficient systems for heating, lighting and other electrical components. Bojen realised that this project would be an ideal way to further develop their understanding of environmentally sustainable housing. It was intended that they would use this project as a test bed for further developments into the disruptive technologies necessary to move the UK away from an increasingly inefficient centralised utility business model.

The Company’s primary objectives were to deliver ten environmentally friendly, energy efficient apartments on a budget and under a challenging time scale, along with coordinating and designing electrical and mechanical systems in line with all the other trades on site. In order to maximise energy efficiency, the apartments needed to have heat recovery systems, period external LED lighting and internal LED lighting and controls.

Detailed meetings were held in March and April 2015, with active work commencing late May. The project was completed in April 2016, although the Company continue to monitor system efficiency, making adjustments where possible to further fine tune operating parameters.

Advance(s) Sought:

To design and build the most environmentally friendly properties possible within a limited budget, whilst ensuring the build was in-keeping with the local area and entirely sustainable, thus providing tenants with efficient, comfortable, modern properties to live in without incorporating large energy bills.

Bojen needed to undertake value engineering on the cost of the different heating and lighting systems to ensure it fell within the client’s budget.

Design and development of heating, hot water and lighting systems to find the most energy efficient and environmentally sustainable outcome. During this process the Company determined that part of the solution should include air-source heating incorporating Eco-cent hot water cylinders combined with heat recovery.

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Technical Challenges

Primarily, the challenge lay in determining how adaptable Bojen’s analysis, design and build processes could become. If efficiencies can be made throughout the entire procedure, then overall costs can be reduced, thus making these new technologies more affordable to a far wider range of clients. Using different build projects as test beds allows the Company to find solutions that can be utilised in other situations.

Due to variations between these various design and build projects, development of different “disruptive” technologies is often necessary at each site. In the case of the Old Gaol, use of air-source heating is more appropriate than, say, ground-source heating, or solar panels. That said, use of air-source heating posed a further challenge, given that the Old Gaol is a Grade II listed building. No fundamental changes could be made to the fabric of the building, so determining appropriate – and efficient sites for intake and outlet ports was an issue.

Overall, it is how the disparate systems can be developed and utilised to produce the most efficient solution that underpins all of the R&D undertaken in the wider ‘environmentally sustainable housing’ project.

Resolution of Challenges, Project Outcomes and Future

Bojen worked through numerous configurations, developing systems as they went, to arrive at the most efficient set up for the available budget. The fact that this project was running alongside a similar project meant that the Bojen team could draw comparisons, thus aiding with development on both projects.

Development of the air-source heating was troublesome in places, due to the difficulties in finding suitable sites for intake and outlet ports – not least because of the restrictions of working on a Grade II listed building. This resulted in the need for significant amounts of ducting, which had to be incorporated in such a way as to not impact on the interior spaces of the apartments. Additionally, various ducting materials were tested for their thermal efficiency, with the best (within budget) option used. Bojen have identified this area for further development, so that future work on listed buildings can be undertaken at reduced cost. As such, they are actively seeking other clients who wish to develop listed buildings.

Overall, the project to develop ten new, energy efficient apartments was a success. The apartments, indeed the whole building, is environmentally sustainable and all work was completed on budget. Sales have been generated off the back of this project, as Bojen market their successes to a wider audience.

Key Staff Involved:

  • Wayne Bound – Designer and project manager
  • Craig Jennings – Co-designer, quality control and technical advisor
  • Nikki Bound – Client liaison and financial controller
  • Lee Harris – On-site foreman
  • Grant Quick – Electrician
  • Owen Sharp – Apprentice electrician
  • Scott MacArthur – Apprentice electrician


Three subcontracted specialist electricians (A Cousin, A Stone, M Mitchell) were used on this project.


The Company had to create a control box to house all the hot water contactors and control equipment that would fit into a limited space and still allow for safe installation; as well as accessibility for subsequent inspection, maintenance and ‘end-of-life’ replacement.

The prototype was initially used for demonstration purposes, but then became ‘first of class’ when it was installed (along with nine further control boxes) to complete installation in the ten apartments.

“Thanks to all Bojen Staff who worked on recent Bio Centre project for the excellent standard of work. We found Shaun very helpful and a great communicator with a very pleasant manner, always ensuring all variations were discussed with me first and service disruption kept to a minimum. The site was also left very clean and tidy. I hope to be able to work with Bojen again in the future.”

Mr T Davies | UK Bio Centre

“We were delighted with the entire process from beginning to end! The team listened to our requirements, made excellent suggestions and we felt cared for and valued as customers throughout the process.”

Graham Carson | Inca – Caring Accounting

“Just wanted to convey to you and your team that I was very impressed with the quality of your installation. The project was completed on time to a high standard with very few defects, which is a credit to your team.”

Brian | Hoare Lea Consultants

“I use Bojen electrical on many University Projects, they always provided an excellent service in terms of project management and quality of installation, I would have no hesitation in recommending Bojen to others.”

Rob Gregg • Deputy Electrical Engineer | Oxford University

“We have and would recommend Bojen Electrical. They are friendly, helpful and well-priced. We have been very pleased and impressed with the very varied work they have done for us.”

Sister Marie Ann | Headington Convent

01235 559358