What Is Retrofit?

What is retrofit?

Retrofit means any improvement to an existing building aimed at improving its energy efficiency, making it easier to heat, able to retain heat for longer, and replacing fossil fuels with renewables is a retrofit.

Why retrofit? 

A significant challenge the UK faces in its quest for net-zero energy is retrofitting our homes and buildings. As a nation, we must prioritise retrofitting to bring our existing buildings up to current standards. This will help reduce our carbon emissions so that we can reach our target of net zero by 2050.

One of the main issues with housing in the UK is we have the oldest building stock in Europe. “The UK has the highest proportion of all EU nations with homes dating back to before the Second World War, at around 38% in 2017.” Source 

Another issue we face in the UK is supply and demand. There is not enough land available to build new homes in the UK to meet the demand. For many people, the only option they have is to alter an existing building to fit their individual needs. If you’re considering significant works to your home, it is important to consider that any changes you make may be locked in for several decades. It is critical to get it right.

What are the benefits?

Two of the biggest problems facing the UK are the need to reduce carbon emissions and rising energy prices. Coincidentally two of the most significant benefits of retrofitting are lower carbon emissions and energy savings. And if a home retrofit also includes some form of energy production, they consume less energy and are better protected against energy price increases while producing lower carbon emissions.

There are also additional benefits of retrofitting that are not as widely discussed. This is especially true if the retrofit is designed to a higher standard, such as EnerPHit or the AECB Building Standard.

Comfort   

Additional insulation and airtightness improvements added during a retrofit make a draft-free home easier and quicker to heat. A mechanical ventilation system helps create a uniform temperature throughout a home. Both make for a more pleasant and comfortable home environment.

Health 

The recommended daily temperature for homes is between 19-21°. Conditions and diseases linked to cold home environments range from increased blood pressure to pneumonia. A cold home can potentially exacerbate an existing medical condition and/or generate new ones. 

Less noise pollution 

Even though it isn't immediately life-threatening, countless studies demonstrate that persistent, unwanted noise can have a negative impact on your health. Noise pollution has been linked to increased mental health conditions such as anxiety and depression, as well as other health conditions such as high blood pressure, heart disease, and stroke. A retrofitted home will be more airtight and have windows that help to reduce external noise. 

Self Sufficient 

Through energy-efficiency measures like insulation and renewable energy, homes can become self-sufficient and reduce energy costs.

Pride  

Making improvements and investing in your home generates a feeling of pride. You can rest easy knowing that you contribute to a better, more sustainable future for everyone.  

How is it done, and what are the challenges?

Retrofit involves understanding how the building performs and redesigning it to work differently. The redesign can be spatial to find space for new building systems and also consider how all new energy-saving measures work together. Every home has unique characteristics, such as how space is used, how it was built, and what adaptations have been made since initially constructed. All of these attributes influence how the dwelling will be retrofitted.

Although most homes benefit from retrofitting, older homes have the most significant margins for improvement. This is because older properties have more problems. The most common issues are dampness, condensation, draughts and lack of insulation, making them harder to heat.

It is essential to take a whole-house approach when retrofitting. How long a sustainable home retrofit takes will depend on the size of home and extent of the work. Don't just focus on energy bills but also incorporate aesthetics, comfort, heritage and maintenance.

We advocate a fabric-first approach, where the measures to improve the home's energy efficiency are considered first, such as additional insulation, upgraded windows, and enhanced airtightness detailing, before considering energy-efficient heating or ventilation systems.

Significantly changing how a building performs does have risks. Some risks of retrofitting a building are overheating inadequate ventilation, and incompatible insulation. Getting the design and energy balance right is critical.

Is there a framework for retrofit?

Passivhaus and related standards are excellent for providing a framework, even if certification is not sought.

The Passivhaus EnerPHit standard recognises the difficulty of applying Passivhaus to existing buildings, setting less stringent airtightness and heat demand targets for certification.

The AECB Retrofit standard is modelled off Passivhaus and is even less stringent than EnerPHit.

Both are certifiable standards that deliver significantly better homes compared to those built to the UK building regulations.

I understand that Passivhaus retrofit is intrusive and expensive. Should I even consider it?"

Like anything made to higher standards, retrofitting a building to Passivhaus levels is more expensive. Recently, the cost has come down as more people embrace it.

Still, most of our clients love the standard but are scared by the potential costs and the constraints of a complex system. Our process involves looking at a project holistically and then implementing the "quick wins" that give the highest return on investment. We use our Passivhaus knowledge, even when designing non-certified retrofits, to design a healthy, sustainable, energy-efficient home. A Passivhaus (PHPP) energy model and a parallel cost model can give valuable insight into the cost of additional measures and the impact on energy performance. By applying Passivhaus even halfway, you will have a healthier, more comfortable, energy-efficient home.

Here at CMA we believe in the power of architecture to improve the lives of people and their environment, hence why we support the Architects Journal RetroFirst campaign and we’ve signed up to the RIBA Architect’s Declare movement.

If you are thinking of starting a project and feel that what we mentioned in this article might be relevant to you, contact us, we will be happy to help.