What is retrofit?


/ˈrɛtrəʊfɪt/ Verb

to furnish with new or modified parts or equipment not available or considered necessary at the time of manufacture

Sustainability and energy efficiency are at the forefront when it comes to new building design, but how do we make sure older buildings and any buildings already constructed can benefit from new or environmentally friendly techniques, that might not have been available when they were originally built. That’s the idea behind retrofit. It’s going back and looking at how we can and improve existing housing to be more comfortable, sustainable and energy efficient.

Retrofitting means fitting new systems designed for high energy efficiency and low energy consumption to buildings previously built without them. This can include things like installing loft or wall insulation, double or triple glazing or replacing an existing gas boiler with a ground or air heat-source pump.

Why Retrofit

The built environment is a significant contributor to the climate crisis:

The energy required for UK buildings accounts for 27% of the country’s annual carbon emissions within that 18% comes from our domestic housing

For the UK to meet its net zero target by 2050, large scale retrofit of the UKs housing stock is required. Not only will it have a considerable impact on CO2 emissions, but more efficient buildings will be cheaper to run, reducing fuel bills and fuel poverty, improving the lives and wellbeing of residents, and it will increasing the value of properties.

The Retrofit process

There are two main types of Retrofit approaches:

Fabric First 

A simple straightforward approach to upgrade the fabric (e.g. walls, lofts, floors) of the building, together with making sure there is the right amount of ventilation, before looking at the more complex systems like heating, hot water, or lighting. This can be done by improving insulation around the building and reducing heat loss through any ‘leaky’ parts of the house.

Whole House

This is where a plan is designed for the whole house – the fabric, services and systems the energy used. it also looks at how the occupants live in and use their home and if there any special circumstances affecting the dwelling. A phased plan is produced and costed, giving estimated energy savings for each measure and the amount of carbon reduction that can be expected for each phase.

VOR’s Approach to Retrofit:

VOR’s approach to retrofit design is in three stages:

  1. Reduce the space heating demand fabric first
  2. Remove fossil fuel heat sources and replace with low carbon alternatives
  3. Generate renewable energy on site wherever feasible.

In order for net zero to be realistically achieved in the UK, the national renewable energy generation must match the energy use of the buildings. Not only will an increase in renewable generation help target this, but a reduction in the demand is the most efficient and cost practical way of meeting that target. However, reducing the demand has to be done in a holistic way. VOR believes that to achieve the UK’s net zero ambitions that a reduction in space heating demand as well as energy use has to be achieved

Establishing Archetypes

For large scale projects, VOR first looks grouping properties by archetypes, and designing a retrofit process that fits each archetype. This allows for economies of scale and to establish a cost and benchmarks for whole projects

What is PAS 2035?

The government conducted an ‘every home counts review’ and as a result of this introduced PAS 2035. PAS 2035 sets out a standard for retrofitting domestic properties and allows retrofit professionals to take a holistic approach when implementing sustainable retrofitting techniques. In addition to the type of work carried out, PAS 2035 also ensures that this work is of an acceptable standard.