Key Post Draughty house /Cold house FAQ


Frequent Poster
Air-tightness and Insulation are 2 different causes of heat loss, but must be paired with proper ventilation and the correct material installation, to avoid condensation and a lack of fresh air that can lead to health issues in our homes

Most up to date architects and often the more practical architectural technician/ technologist, can advise on building fabric issues. (Please do not employ a BER assessor unless they have an arch, structural engineer or building surveying background). Form here your professional will direct you to appropriate materials, installers or consultants such as air-tightness or damp specialists. With air-tightness and insulation many situation has several possible solutions but often just as many consequences and that's why a professional consultation is worth while.

We have a population that is now aware that energy costs will keep rising but they want cheap solutions to reduce heat loss and improve their less than adequate home comfort. There are generally two distinct levels of dealing with drafty or cold houses: Invasive often considered expensive work (60 labour: 40 materials approx) or the DIY’er messing about with expanding foam and silicone. The latter suits most people (until there's a problem) when it’s often the former that's required.

The following are a few articles/references that give some good pointers

regulations and government reports
Limiting Thermal Bridging and Air Infiltration Acceptable Construction Details
EST Airtightness+Case+Studies
A practical guide to building airtight dwellings
refurb-airtightness (read and scroll to the end for more good links)
the new Building regulations now covers alterations to existing buildings and sets out a certain standard part L TGD 2011 also see: BuildingStandards

air-leakage & quality




case study of a dry-lining retro-fit (note the use of natural breathable-construction materials)

josephlittle's studies breaking the mould
insulation-upgrades-outside (external wall insulation)

airtightness-membranes and tapes: the Irish market leaders are probably proclima or siga as they offer some sort of guarantee lifespan

here's one forum where the poster dealt with drafts properly

a few other reports:
Condensation risk – impact of improvements to Part L
Advanced calculations of moisture movement in structures
BS5250 Code of practice for control of condensation in buildings
Bre 297 surface condensation and mould

Brendan Burgess

Hi low

That is excellent. Thanks very much and I have made it a Key Post.

Can you say a bit more about professionals to consult. Is there a particular qualification or membership of a professional body which one should look for?
It's interesting that you say to avoid BER assessors.

Are there particular specialist firms you would recommend?


Frequent Poster
It's interesting that you say to avoid BER assessors.
i dont mean to knock BER assessors, and they provide a valuable energy rating service which is a requirement under current legislation, but i have had disagreements with certain builders and auctioneers that became BER asssessors and found themselves advising on insulation, air-tightness, heating systems etc and some (who are not qualified as archs, AT's, engs, or building surveyors), IMO are not best placed to advise or appreciate the consequences of there advice. also their probably not insured for the consequences either..

I hope to add a few links to forum posts, where questions have been raised/asked/answered over the coming weeks


Frequent Poster
the stages and tip for renovating/ refurbishing/ retro-fitting your home

I have put together for you a list of the stages and General Top tips for how to go about renovating/ refurbishing/ retro-fitting your home. Rather than go into specific details, take a look at this article home-upgrades-top-tips-refurbishment

1) The article above suggested when retro-fitting an architect should be hired that:
can prove s/he does their own U-value calculations, has a good understanding of energy- efficiency, thermal bridging, inter-stitial condensation control and different insulation strategies
. I agree with this, but would broaden this category to architectural technicians given the technical nature of retro-fitting and generally the lack of design input required. So from here on in, I’ll describe your professional help as ‘arch’.
Many Arch’s will provide a BER service also.

2) A BER is required for all new buildings but only required if selling, renting or seeking grants for existing buildings. Grants are available for homes built before 2006. This gives you an idea of how poorly we valued insulation and air-tightness in the past, and why it’s important if you are looking at improving your homes performance that you carry out any works to the highest standard possible.

3) Before decorating, installing that new kitchen or changing your heating system, deal with the fabric of the building first. That means windows, air-tightness (drafts), insulation, and not forgetting the homes ventilation strategy. And only after you reduce the homes heat loss, should you start to think about heating systems or renewable technologies.

4) Many homeowners find they have problems with one or several of the following: damp patches, condensation, mould, heat loss, drafts, stale stuffy air, and unexplained illness. Problems can be made worse where one symptom is treated without consideration for the others. For instance, I recently visited a home where the attic had been insulated, and was told that the increased insulation had caused mould in some spots on the ceiling. This turned out to be damp insulation resting on top of the plasterboard ceiling, caused by the insulation in contact with the roofing felt and that felt/roofing space not getting enough ventilation to evaporate the normal amounts of moisture that occur in non air-tight attic spaces. It’s easy to blame the insulation but really its how it was installed that caused the problem.

5) Check out What_Grants_Are_Available , the Grant FAQ and inform yourself before rushing into anything.

Read the literature that the SEAI has made available:
and what is considered to be best practice Passive_House_Retrofit_Guidelines

Then you’ll feel more confident to ask detailed questions of your arch or contractor.

6) First be clear with your chosen Arch about what is included in their price, ask how they propose to manage the contractors work and what happens if you are not satisfied. As it is often not possible to oversee/ supervise all works on site especially given peoples budget constraints. To ensure the work is done correctly, the approach I take is to specify and check previous work of all contractors, check there products, check the work in progress and then the finished product. I often make the specification performance related and use (or sometimes just treating to use) the services of a thermal imaging / air-tightness tester to check that the work has been done to a good standard and there are no major air-leaks or apparent discontinuous insulation.

7) Much of time a home-owner may feel that much of this work can be done by them, by all means, this should be encouraged, but immediately it limits what work can be done and to some degree the standard of workmanship that can be achieved. For any DIY’ers out there I would recommend the following air-tightness course . I’m sure there are others, this is just one of them, I have no connection. And here’s some more courses, again not a complete list by any means. SERVE-Seminar-Series

Also keep an eye on easca & cultivate for more courses and I recommend for those with an interest in home building & energy conservation to visit the
constructireland magazine and review its FREE back-catalogue.

8) Don’t get trades/contractor/builders in to give you quotes until you have a detailed specification. And where 2 elements such as windows and insulation are being improved – ensure you have details that builders can price and work too. Get at least 3 quotes! And use your Arch to help decipher the best opinion for you.

9) Often lower budget retro-fitting work means that no formal contract is entered into. However, all trades should have the correct insurances for working on your property; their products should have the proper certification, must be installed as per this certification and workmanship guarantees/ product lifespan guarantees should be provided. Ensuring these guarantees are in place and the work is satisfactory before the contractor is paid, is how the Arch earns his/her fees.

10) Why bother with all this? Why not just go to the guy whose going do the work? The contractor/installer! All I can say is that, there is no real building control in Ireland, and although an installer may be registered with the SEAI and have IAB certification, no one checks that the right material is used in the right situation. Each installer is generally pushing a particular product and no one checks the quality of this work. It is a myth that it is the BER assessor’s responsibility, as the assessor is not insured, paid or in some instances experienced enough to check the quality or appropriateness of workmanship and is only there to check the materials are in place to be eligible for a grant.