External Insulation

November 24, 2008

In cases where existing houses require wall insulation but do not cavity wall insulation is not a viable option, the more expensive option of installing of external insulation may be considered. External insulation involves fixing insulation materials such as mineral wool or expanded polystyrene slabs to the outer surface of the wall. This insulation is covered with a special cement-based render or aluminium skin to provide weather resistance. The insulation forms a barrier to heat transfer and reduces losses through the wall space. One of the main benefits of the external insulation over internal insulation is that loss of internal space is avoided. When installing external insulation, it may be necessary to extend eaves and sills and relocate downpipes to accommodate the extended footprint of the building.


Another important characteristic of external insulation is that it will maintain the houses heavy weight slow thermal performance. This means that the houses walls will absorb some of the heat when the heating is switched on, reflecting it back into the house after the heating has been turned off. The disadvantage however is that it will take longer for the heating system to heat the house up in the first place.


Another advantage of external insulation is the chance it allows for upgrading the aesthetics of the house. The chance to re-clad an aged house is often a major attraction to external insulation. This benefit can also be essential to making the economics of a project.





Secondary Glazing

October 30, 2008

Secondary glazing provides an excellent alternative to double glazing in cases where replacing the existing windows is not possible due to preservation orders, though as the seal is not as tight as double glazing, the reduction in heat loss through the window is not as much.

The idea is this, a second pane of glass on a light frame is attached to the inside of the existing frame. This second pane reduces heat loss in two ways. Firstly if creates a barrier between the warm inside air and the cold outside air, reducing convection losses. Secondly it traps a layer of air between two panes, reducing heat loss through conduction.

In cases where the window must be open-able, secondary glazing products are available which allow for this requirement. Options such as horizontal sliders, vertical sliders, and hinged units are available. Magnetic, clip on and screw on units which can be installed during colder months are a cheaper and more robust solution.

Curtains – the best value for money energy saver

October 28, 2008

Curtains can reduce heat loss in the winter by 10% – 25% and reduce drafts significantly. So considering their relatively low cost, and other benefits, are a very good investment. They do this by providing a barrier between the window, and the main room. In general windows have the poorest U-Values in an average room, and so are the focus of most heat loss during colder times. Warm air circulates around the space due to convection and is suddenly cooled when it touches the relatively cold windows. Curtains act as a barrier to this air flow, and so reduce the amount of air being cooled.

Here are some tips to help you save energy with your curtains:

  • Actually use the your curtains when you have them available
  • The more completely the curtains cover the window the better, so have large ones with plenty of overlap and overhang at the ends
  • Lining in curtains reduce air infiltration through them, and so is well worth the investment
  • Curtains should be hung as close to the window as possible to reduce air leaking in from the side.
  • The longer the curtains the better.
  • Install a cornice at the top of a curtain
  • Use Velco to attach the ends of the curtains to the walls and to each other in the centre
  • Blinds do little to reduce heat loss in the winter

Draft proofing hinged windows and doors

October 22, 2008

When draft proofing  hinged type of windows or doors, similar principles can be used for the sides and the top of doors as with the top and bottom of sash windows. First you need some compressive foam seals, or in some cases a roll of soft polystyrene can be a cheaper solution. With the door or window open, these are fitted to the frame on the top and sides of the door or window, along with the bottom of the window frame. When doing this it is important that you cut the strip to the exact size required to provide as tight a seal as possible.

With regards to external doors, the base of the door is often the worst source of drafts following poor installation and years of wear and tear. The solution is a bristle strip, cut to the correct length and attached securely to the base of the door.

In some cases, where very large gaps are present, it may be necessary to install an aluminium strip to provide an even surface which can be used form a tight seal.


Finally, with regards to doors mail boxes and key holes are a source of drafts, and should be fitted with appropriate covers.

Have you Weatherized you house?

October 19, 2008

Weatherization, what a great word. It refers to protecting a building from the elements, or for the purpose of this blog, the particular elements of wind, snow, cold and rain. I’m particularly interested in things you can do to improve energy efficiency and comfort. Anyway, here is a bit of a list

  • Air sealing cracks, gaps, holes around doors, windows, and in walls
  • Block up and insulate gaps around pipes that penetrate the attic ceiling, and other areas with high potential for heat loss.
  • Protecting pipes from corrosion and freezing.
  • Installing drains, foundation waterproofing membranes, downspout extensions, downward-sloping grading, French drains, etc to prevent water flowing under doors or lodging beside walls
  • Insuring that roofing, building wrap (walls), siding, flashing etc can prevent wind, rain or snow from getting in (depending on how much is possible for your area)
  • Have enough insulation to reduce heat losses to an acceptable level
  • Providing proper ventilation to unconditioned spaces to protect a building from the effects of condensation.

Draft-proofing sash windows

October 13, 2008

The two materials you will need are bristles strips, and compressive foam seals.


First open the window. Put compressive foam seals on the underside of the top and bottom edge of the window (Marked A). When doing this it is important that you cut the strip to the exact size required to provide as complete a seal as possible. For wider frames it may be possible to install a second layer of compressive frame seal.

Next, close the window, and fit bristle strip to both sides of the beading of the lower sash (Marked B). Do exactly the same for the upper sash BUT on the outside.

Finally to draft proof where the sashs meet (Marked C). Bristle strips should be fitter on both sides with the bristles facing each other just touching. This will stop drafts coming in the middle.

Do your part to stop the downturn in the building trade- Insulation your home

September 3, 2008

The other day I listened to CIF, the Irish building federation, extol the virtues of people having their homes insulated, draft proofed and double glazed to improve the energy performance, and of course, provide work for small builders. Well it’s not too often that I would agree with those feckers… but this might be the time. In the old days one of the reasons for not having home improvements done was that builders weren’t available, were overpriced, and weren’t motivated to work small jobs… Well this is the opportunity.

From the point of view of the economy… it’s a winner. In Ireland alone, sorting out the worst 10% of houses would generate 2 billion for the trade… not to be sniffed at… would buy a lot of breakfast rolls and low cut pairs of jeans!


Do it for the environment

Do it for your energy bills

Do it for your economy

Do it for the builders


Insulate your home