Deep Retrofit in Birmingham

Deep retrofit of two semi detached homes to Passivhaus standards.
Retrofit project completed by Beattie Passive in Birmingham
Made In The UK
Birmingham City Council
Delivery Method

Elisabete (Resident)

“Before the retrofit, my house was cold all the time, even with the heating on and we did not feel very comfortable living here in the winter. The house is now really warm and we only need to switch the heating on if it is very cold outside. It is also very quiet as we don’t hear noise from planes anymore (house is under the flight path). We sleep very well nowadays and feel very comfortable. One of the best things about the retrofit is the fact that we essentially have a new house with a new door, triple glazing, new roof and new walls.”

We can see the benefit and are fully on board with the reasons to encase or ‘TCosy’ a property as this reduces our building repair commitment due to a brand new exterior and changes, such as removing gas fires, eliminates the need and cost of annual gas checks. Further analysis will take place before any large scale retrofit projects go ahead however this system does also address our social responsibility commitments when targeting fuel poverty, which remains a major issue affecting our tenants in the region.
Joe Muxlow
Contract Team Manager, Green Investment Team

Project Description

The Retrofit Plus Research Project was a collaboration between Beattie Passive, Birmingham City University, InteSys and iZdesign under the Innovate UK initiative for ‘Scaling up retrofit of the nation’s homes. The project involved retrofitting two houses to achieve EnerPHit performance. Drawing upon academic, technological and private sector expertise, the aim was to drive innovation to reduce carbon by up to 100%.

We used our innovative TCosy™ system to transform two semi-detached houses owned by Birmingham City Council.

Using Passivhaus comfort and energy efficiency principles

The TCosy™ system transforms houses and delivers the following benefits for the council and their tenants:

2 houses retrofitted to Passivhaus standard – TCosy™ achieved Passivhaus standards of build. The system incorporates Passivhaus Certified windows and doors and a Mechanical Heat Recovery and Ventilation system. This delivered a high performance, high quality home

Fast on-site build – the Passive Panel system was installed onsite in just a few weeks

Limited disturbance – residents remained in their homes for the duration of the retrofit

Lifted tenants out of fuel poverty – reduced heating requirements and energy bills by up to 85%

Created healthier, more comfortable homes to live in

A new look home – we worked with the council to design a completely new external façade

Regular engagement with tenants ensured they understood the process and benefits of the Retrofit

Increased Asset Value of your housing stock

“We used to be very cold and use the heating a lot as the heating didn’t stay in the house for very long. Some of the rooms used to feel cold. To keep warm, we would often spend most of our time in the living room with blankets. Now we don’t use very much heating at all and the rooms stay warmer for much longer. An added bonus is that the house now looks really good outside.”
Catherine (Resident)

Retrofit Plus Partners

Birmingham City University



With my background and ongoing research into the design of energy efficient buildings with particular focus on achieving zero carbon, we entered an Innovate UK competition entitled ‘Scaling up retrofit of the Nations Homes’. We were focused on developing a system which could be delivered in large volumes and this led us to Beattie Passive. The TCosy™ solution is a very exciting step forward for us in the development of a sustainable and scalable solution for today’s challenge to regenerate current housing to become truly energy efficient. Having investigated the key aspects of successful retrofit, the TCosy™ appears to have significant advantages in comparison with other retrofit system we looked at. In additional to technical advantages, the Beattie Passive system lends itself to alternative business models, and this combination has a considerable market potential. We look forward to collaborating with Beattie Passive on future projects to deliver a sustainable and flexible solution for a scalable zero carbon retrofit.
Professor Lubo Jankovic
Birmingham City University
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