The final stage of achieving weathertight and protecting your home from the elements is the installation of the windows and doors, followed by the completion of the cladding. This month, I’ll take a look at the key issues relating to both elements so that you can make sure your project is built well.
WINDOWS AND DOORS
Of all the products bought by self-builders, windows and doors are among the most expensive. If you’ve ever visited a Homebuilding & Renovating show, you’ll soon realise why — slim sightlines and funky functionality means windows and doors are now uber-cool and a high-performance product with U values capable of being well below 1.0 W/m2K.
Despite the improved performance that windows and doors now offer, in terms of the envelope, they’re still the weakest link, and if not installed correctly the energy performance benefits will be lost through worse airtightness and levels of thermal bridging. Furthermore, bad installations will potentially compromise durability by not accounting for movement and settlement, thereby allowing potential water ingress.
The answer to these problems is design and detailing. Each installation should be well thought through with drawings that reflect the declared Psi values (thermal bridging) and show the
