Condensation and Atmospheric Moisture Management in Buildings

The PCA published its initial thoughts on how retrofit insulation and other energy saving measures can significantly affect buildings, late in 2011. The articles and subsequent White Paper that were published generated some interesting responses and certainly raised a few eyebrows. The premise of our discussion was – and remains – that rather than improving living conditions, ill-conceived, poorly installed or thoughtless retrofit insulation can lead to serious problems with atmospheric moisture condensation and penetrating damp.

The Government’s flagship energy saving initiative, Green Deal, launched quite unremarkably in October. We had concerns that little had been done to ensure that Green Deal assessors understand the need to design insulation measures in a way that will avoid creating atmospheric moisture problems and, since the publication of our discussion paper last year, we found that we were not alone in our concerns. A number of organisations including Chartered Institute of Buildings, Royal Institution of Chartered Surveyors and English Heritage have also been warning of the Green Deal’s potential detrimental impact. Though these warnings relate mainly to the impact on historic structures, we have been reassured to hear critics expressing doubt and concerns very similar to those raised by the PCA.

Throughout the summer we attended a host of presentations and events in an attempt to understand the issues surrounding the implementation of the Green Deal. These events include skills summits, workshops, talks by prospective deal providers and others with commercial links to the scheme. These events, hosted by an array of quangos, training organisations, government departments and private companies, have looked at opportunities, processes and governance but so far we see no evidence that anyone has tried to tackle the issue of design.

ECO is a new programme designed to reduce Britain’s energy consumption and will run alongside Green Deal. It is funded by a levy now placed on energy bill and will be used to fund home energy saving measures and is estimated to be worth around £1.3 billion every year. This scheme will be used to help improve the energy efficiency of hard to treat homes as well as buildings occupied vulnerable or less well-off households. Though we are uncertain about the process that will be used to assess needs and draw up recommendations for energy saving work, again, we see no evidence that the problems we have identified in this article with design have or will be addressed.

Green Deal assessors have a responsibility to ensure that the proposed energy saving measures will meet the Golden Rule (that is, that the expected financial savings must be equal to, or greater than, the costs attached to the energy bill) but will they be responsible for the success of the design? We remain very concerned that financial drivers will prevail and that there is a risk that these will prevent assessors from taking a holistic approach to the design and implications of the limited range of measures they will be allowed to propose.

Insulation and energy saving measures, when designed and installed in adequately heated homes, will help alleviate some problems associated with high humidity and surface condensation. Conversely, however, ill-conceived retrofit insulation in buildings where fuel poverty may be an issue can be the catalyst to problems with high humidity.

Successful solutions that deliver improvements in energy efficiency and living conditions must be considered and designed on a job-by-job basis. Thought must be given to the needs and lifestyle of the occupant as well as the physical constraints, design and nature of the building. The Green Deal surveyor must have the skills, knowledge and freedom to try and strike a balance between meeting the Golden Rule and ensuring the water produced by occupation can be managed effectively.
CondensationThough the initial Green Deal assessment forms we have seen contain a section that considers the way the building is occupied, we remain concerned that the average Green Deal surveyor will arrive on site blissfully unaware of the potential impacts of what they are about to recommend. With little understanding of vapour movement, the effects of differential vapour pressure, relative humidity and interstitial condensation, work will be recommended that will result in damp homes. These views are supported by evidence gathered by PCA members in the field and growing anecdotal evidence.

It is undeniable that much has to be done to improve the energy efficiency of homes and we fully support the principal behind Green Deal and ECO. It remains our view, however, that good thoughtful design by a surveyor who understands the full implications of his or her recommendations, is vital to the long term success of any energy saving scheme. Unfortunately we see little evidence to suggest that our views are shared by legislators.

What many fail to realise is that to manage atmospheric moisture effectively, the relationship between four factors – water production, ventilation, insulation and energy input – must be understood. These elements singularly and collectively affect the conditions within an occupied building. Without understanding the relationships between these elements, finding the right solution to a condensation or mould growth problem can be very troublesome and incur needless cost. By providing instruction we aim to give property professionals the ability to measure these elements and gain a better understanding of the relationships between the factors that influence atmospheric moisture and condensation problems.

Our experience has also shown us that there are sadly very few surveyors who have the requisite skills, knowledge and equipment to investigate and diagnose problems caused by atmospheric moister properly. In response to this, we have developed a number of specialist training courses for those wishing to understand more about dampness and condensation in buildings.

Demand for our short development lectures on condensation and moisture management have increased steadily and we are now asked regularly to give presentations to housing associations, property managers and surveyors on the subject.

Problems associated with atmospheric moisture, mould and condensation are on the rise and this trend is set to accelerate as fuel prices rise and we seal ourselves into our homes. The Property Care Association is in a position to work with our members and the wider industry to ensure that skills and knowledge are in place so that we can respond effectively to a growing need.

Our stated aim is to put the Association and its members at the forefront of knowledge and understanding in this subject and ensure that PCA members are seen by consumers as the people that understand atmospheric moisture and who can be relied upon to solve condensation problems.