Wall insulation for new & existing dwellings

35% of a building’s heat escapes through poorly insulated external walls. Reducing this waste will have immediate results on comfort levels and on the pocket.

New builds:
Leave a gap between insulation panels, when building, and you might as well not have bothered – well almost. Wall insulation is best done properly during construction, and there are a multitude of options for all types of construction, from block build through timber frame and then ICF and hemp construction which forms it's own insulation and wall in one. Even for block built walls there is now polystyrene wall insulation which interlocks horizontally and vertically and therefore prevents gaps being left by the builder. The choice of wall construction and it's insulation to use will be governed by how you use your home, how efficient you want it to be and your budget. Ecodev provides sound advise during the design of your home or when providing a detailed build specification for existing design. This is an area that is best done right the first time.

Retrofitting insulation to existing external walls can be done externally, internally or through cavity fill.
Externally applied insulation is the most effective and quite expensive.
Internal insulation is done through “dry lining” and numerous options are available, including insulation-backed dry lining boards. This can be disruptive and you will lose some floor area in each room. The insulation backed boards with a breather membrane built in is the better option as this helps prevent mould building up behind the boards.

Cavity fill is the third option. Cavity fill has very little disruption & no loss of living space. Go for a reputable company offering a guarantee. It is well worth going for the Silver/Platinum option offering the best insulation. Properly fill any expansion or other larger cracks in the external plaster in advance. Do not under-estimate capillary action of moisture through plaster cracks. It is best to prevent any long term side effects up front.
Check the product installation guide and make sure that enough holes have been drilled, vertically, horizontally and under window cills. Be aware that cavity fill requires a minimum of 40mm available cavity space (left over after the initial insulation) to be effective. In a flat ceiling home, where loft space is not used for habitation, there is no need to insulate the cavities more than 300mm above ceiling level.

General best practise:
Always compare u-values for the various thicknesses of insulation. Google the product to view their specification documents. Effectiveness in insulation is dependent on both type and thickness. In insulation terms, small u-value differences can make a big difference to heating bills.
How do you choose? Together with the relevant u-value of the product and budget, the most important consideration is how to ensure that there are no (hidden) gaps in the completed insulated fabric. The current building regs require a maximum u-value of 0.27W/m.sq for the walls, but any improvements on this will more than pay-off in the long run.

Safety precautions must always be strictly adhered to and Ecodev cannot take responsibility for any actions taken as a result of this article. If in doubt, get the relevant help.
Ecodev provides energy efficient designs, energy usage consultations and BER certification.