Our System

Retrofit Benefits

Retrofitting UK homes and buildings is one of the greatest challenges we face in reducing carbon emissions. But the benefits are absolutely enormous. Retrofitting can put an end to fuel poverty, damp and mould. It raises living standards. And it is an essential part of our journey towards net zero.
retrofit-enerphit-social-housing
Made In The UK

Retrofitting is essential to improve the energy efficiency of the UK’s existing housing stock

Our innovative TCosy™ deep retrofit system will improve the EPC rating of your property. There is no need to move. We work on the outside, while you – or your tenants – remain inside.

The innovative Beattie Passive TCosy™ can easily and cost effectively improve the EPC level of your property.

An energy efficient home not only provides immediate dividends, through reduced energy costs, but also increases market value.​

Draughty rooms in winter? Stifling hot rooms in summer? Retrofitting your home will enhance the comfort of your entire home by addressing thermal bridges and poor insulation.

Retrofitting existing homes to Beattie Passive standard reduces deaths and illnesses related to cold homes. Installing MVHR within the TCosy™ frame improves health through enhanced ventilation and dramatically reduces the risk from radon.

Our design team will import any house design, shape or style of architectural drawing into our 3D modelling system. From here, we will deliver a custom-made package that incorporates all the Passivhaus principles into our TCosy™ system for you.

Our method of construction offers an easy to assemble and highly replicable frame-link retrofit system. Due to the simplicity of the TCosy™ retrofit system, it can be built by semi-skilled labour. At Beattie Passive, we’re passionate about developing skills in the industry and regularly work with colleges and development centres.

Adding MVHR and quality windows to a Beattie Passive retrofit structure reduces your heating requirements by up to 90%. Such a dramatic reduction in space heating demand can actually save people from falling into fuel poverty.

By using the Beattie Passive structure, MVHR and photovoltaic cells together you can achieve up to a 100% reduction in CO2 emissions.

Existing Building Regulations | Beattie Passive
Thermal Efficiency/U-values: 0.28 | 0.12
Airtightness: 10 | 1 and below

The simplicity of the TCosy™ system allows for fast on-site construction. The Beattie Passive TCosy™ is designed to be manufactured locally at any location using readily available materials. As a factory manufactured system, it does not have an extended lead time for procurement.

The use of our bespoke 3D modelling design allows all materials to be measured to within a single millimetre, which greatly reduces on-site waste as well as over-ordering of materials.

All materials used are from a fully certified supply chain.

Building control officers can study 3D drawings before arrival on site and all structural joints are open to inspection. As a result, only one inspection is required to see all structural joints and fixing on completion of the structural build. An independent thermal and airtightness inspection confirms the retrofit has been properly constructed and insulated.

The Beattie Passive TCosy™ process results in minimal disruption for the resident. The system is easily constructed while the resident stays in their home for the duration of the project. Residents experience minimal disturbance when windows and doors are changed and the MVHR is installed.

We inspect and independently performance test every Beattie Passive TCosy™ to ensure the highest standards of construction are maintained. We also carry out stringent airtightness and thermal continuity imaging upon structural completion. We will only issue a quality assurance certificate when the design standard has been achieved. We test at the right time, every time.


In terms of energy efficiency and living environment, many homes are no longer fit for purpose and look tired but remain occupied. TCosy is more cost effective and quicker than a re-build, avoiding the temporary re-location of residents. The updated contemporary look lifts and enhances the local environment.
Ron Beattie
Founder & Managing Director, Beattie Passive

See our TCosy solution in action

Retrofitting will improve your energy efficiency, carbon footprint and living standards
Get in touch today to speak to our expert team