There are a number of ways you can insulate your exterior walls, with the most common being blanket insulation or boards. These are available in a range of R-values and can be fitted to both new and existing walls, although installation is best left to professionals. If you do choose to undertake the work yourself, follow the manufacturer’s instructions carefully and be aware that the maximum R-value of the insulation is highly dependent on its installation.
Another option is to fit 70mm thick rigid foam insulation mechanically fixed to the wall before cladding it with a sand and cement render or timber cladding. This is much cheaper but it does mean that the wall becomes non-breathable, which may or may not be an issue.
For those renovating a house with solid brick walls there is also the option to insulate the outside of the property. This will have a slightly higher cost than cavity insulation but is very effective in reducing heat loss and stopping cold bridging at wall junctions, window and door reveals etc. To find out more about Insulation Render, consider APS Plastering who supply Insulation Render services.
There are a few different options for this, and the best one really depends on your budget and timeframes. The most effective is injection foam, which creates an air seal to keep the hot or cold air that you pay to heat or cool in where it should be and not out of your home. This can be sprayed in place or injected via a pump, with both types available as DIY kits but a professional job is far superior.