WUFI is the world leading simulation software for understanding the risk of interstitial condensation, mould, rot and freeze-thaw in buildings – simply put its ‘hygrothermal’ simulation.The Fraunhofer Institute invented the software after hugely contributing to the world’s understanding of building physics since World War II. Shortly after the European standard for numerical simulation (EN 15026) was created in 2007 the Fraunhofer were able to validate WUFI Pro. There are now thousands of users around the world and growing fast. Join the growing ranks of WUFI simulators!

Click here for those interested in training in hygrothermal simulation: http://www.buildinglifeconsultancy.com/training/. The one-dimensional WUFI Pro will be taught on 19-20 April and the two-dimensional WUFI 2D will be taught on 23-24 April.

If you’re interested in downloading a copy of the presentation (before the organisers get around to uploading it) you may like to know that it’s a repeat of a talk given at the Passivhaus Trust conference last October in the Barbican Centre. Click on link beside ‘Joseph Little’ at: http://www.ukpassivhausconference.org.uk/25th-october-2011

Click here for those interested in training in hygrothermal simulation (i.e. a part of which is to do with assessing interstitial condensation and mould): http://www.buildinglifeconsultancy.com/training/. The one-dimensional WUFI Pro will be taught on 19-20 April and the two-dimensional WUFI 2D will be taught on 23-24 April.

Simulation Set-Up
The first stage of the simulation is to create the component build-up within WUFI. Based on the description and the detail shown, the WUFI build-up of the original roof is as follows:

Original Roof Build-up

To simulate this build-up with the cellulose, the air space is replaced with cellulose as follows:

Roof with Cellulose Fill

Evaluation Criteria
To assess the health of this build-up, the critical values to look at are the water content of the plywood and the humidity levels on the cold side of the insulation where the plywood may be trapping vapour. Rotting of the plywood becomes a concern if the water content is above 20%-M (%-M = mass percent = kg of water/kg of dry material). Humidity levels at the cold side of the insulation should stay below 80% to avoid mould growth within the roof. To determine if the interior moisture load makes a difference, the simulation was run with interior climate set to a “Normal Moisture Load” (typical of a living room or bedroom) and a “High Moisture Load” (typical of a shower room or kitchen).

Results
Simulating the cellulose filled roof with a normal moisture load, gives the following water content at the inner and outer 1mm of the OSB board.

Please use this link to view brochure, programme, costs & assisted funding arrangements, etc: http://www.josephlittlearchitects.com/blc_training.html

This hands-on training course will teach participants to calculate linear and point thermal transmittances and temperature factors for 2D and 3D thermal bridges, to meet the latest Irish, British and European (EN ISO) standards.

The workshop is intended for architects, engineers, insulation suppliers, system manufacturers, builders, and any building professionals with a focus on fabric performance and detailing. No previous experience is required.

Please use this link to view brochure, programme, costs & local funding arrangements, etc: http://www.josephlittlearchitects.com/blc_training.html

On the 12th of September we will participate in a free public talk in Glasgow, organised by Historic Scotland, to launch “Historic Scotland Technical Paper 15 – The science of getting insulation retrofits right – Heat and moisture transfer in traditional stone walls”. It should be very significant: we’re looking forward to it.

This workshop will teach attendees to use Fraunhofer’s WUFI® Pro software for simulating heat and moisture transfer through building fabric for the purpose of assessing risk and preventing interstitial condensation. Focus will be on the practical application of the software with emphasis on its use in the UK and Ireland.

The workshop is intended for architects, engineers, insulation suppliers, system manufacturers, builders, and anyone with a focus on interstitial condensation, healthy buildings, conservation and fabric performance. No previous experience with the WUFI® Pro software is required.

Now as we strive to reduce energy use and increase the insulation levels and airtightness the effect of well-fitted but poorly thought-out systems, or badly built well-designed systems are becoming more obvious. The moisture or vapour accrual can be greater than before and the (accidental or designed) air movement that took moisture away may be less available.  Old-school architects and builders have little understanding of how ‘tipping points’ can be reached in terms of building physics where insulation levels can start causing more problems than they solve.  It is our view that the whole industry needs to re-think, re-learn and upskill.

Add this to the fact that Ireland has some of the poorest ventilation regulations in Western Europe and that most Irish homeowners have no understanding of the importance of ventilation and therefore block vents or have inadequate extraction and you can understand why it would appear we are on the cusp of a significant number of building failures.

It doesn’t have to be that way.  We have the tools.

Go on – visit the site and contribute your name: http://www.energiseireland.ie/manifesto.html

In all cases the quality of the work and the specification of the materials and design will greatly affect the cost. Remember compare apples with apples! ‘I’ll do ya a cheaper job Misses’ normally means ‘I’ll significantly drop specification then charge for extras once I’m on site’!

Refitting a bathroom: allow €1000 for supply of typical sanitary ware (bath, wash hand basin, toilet and shower unit) & €400 for fitting of same. Allow €50 per sqm for supply and fit of tiling. A typical bathroom could be fully tiled (floor and all walls) for ~€1500. Make sure to go for dual flush low volume toilets and shaped baths both of which reduce wastage of water.

New windows and doors: Prices range from ~€8k-25k. PVC can be half the cost of good Scandinavian pine windows. Remember most of the trade in PVC windows these days is in replacing older PVC windows: don’t listen when suppliers tell you PVC windows have no maintenance and don’t age! Get the best ‘whole window’ thermal performance (U-Value) you can afford and think about the width of the frame: how much light are you losing? Some window systems have very wide frames, to the extent that they reduce light ingress and can actually result in the external appearance of the house disimproving! Walk down your street beforehand and see what window replacements compliment the original design of the neighbouring houses and which don’t.

New wooden floors throughout: Allow €10-60 per sqm for supply and ~€25 per sqm for fitting. Remember a solid walnut wide board floor will be a very different cost and feel to an engineered oak finish floor. Try and source sustainable timber whenever possible. Look for the PEFC and FSC-certified marks.

Attic conversion: Standard price could be about €15-16k. A specialist creating a fire-rated, well-insulated bedroom can be at €20k. Prices for an installer travelling from outside Dublin could be as low as €10-12k. Remember that if the attic conversion is to be used as a bedroom you need to obtain a fire safety certificate for the works which will include upgrading all doors on the First Floor landing to fire-rated with door closers. The custom of the builder, homeowner and estate agent all agreeing (with a nod and wink) that it’s not a bedroom but a ‘store’ puts children’s lives at risk.