Time and again we discuss with Retrofit Assessors, Coordinators, clients and contractors, how much information do we actually need to complete the retrofit designs? The easy answer is as much possible, but this brings with it time and cost implications as well as the practicalities of getting survey information on properties that are generally occupied.

PAS2035 is the specification for the energy retrofit of homes and sets out a pretty clear

process for the assessment, design, and implementation of energy efficiency measures. There is very clear guidance, with PAS 2035 Process Maps, for assessors, coordinators and designers to follow to ensure the way we approach retrofit, and the information we get, is sufficient.

However, ‘sufficient’ is still not always enough. We see a lot of Retrofit Assessments. A lot. And the variety of the amount, and presentation, of information varies enormously. Whilst they all meet the PAS2035 requirements, some are clear and concise and easy to read, some less so. Some provide a lot of information about the property, some less so.

We can design with whatever information we get but, as with most things in life, the more you put in, and the better quality you put in, the more you get out and better quality. The key is how much on-site (read expensive) risk you want to take as a client or contractor. The less information we have, the more unknowns can be discovered on site where the impact on cost and time is much more significant than discovering these things in the drawing office.

As a bare minimum we want the Retrofit Assessments, and we always provide an example to our clients of a good quality assessment to use as a benchmarks when appointing RA’s. We often get measured surveys that are better than the basic we would get with an RA, site photos, thermal imaging, content reports (which list out construction types, thicknesses and sometimes estimate of windows and door replacement dates) and a boroscope survey all of which help us to understand better the existing properties. Sometimes we need to get intrusive surveys where we open up areas to check assumptions and this is especially important for hard-to-treat properties (like Victorian terraced street houses), Conservation Areas or Listed Buildings.

Just a site walkaround a chat to some of the residents can provide some insights that following the PAS process can miss.

We also make sure that we are collating and organising the information as we receive it in a manner that is easy to understand and access and we are starting to build up a database of recurring patterns and themes in different property types. This enables us to see any unusual findings or anomalies that we need to double check. It also means we can make a better guess at some of the properties we can’t access.

There will always be things that we find during the works that we did not anticipate. Always. But overall, we cannot have TMI. The more we know before we are on site the smoother, more cost effective, quicker and significantly less disruptive to residents we can be.