RETROFITS FOR NET ZERO HOUSING
RETROFITS FOR NET ZERO HOUSING – here’s a model that could actually work!
Nov. 8, 2021
https://issuu.com/greenallianceuk/docs/reinventing_retrofit/22
I’m very excited to see this comprehensive solution presented at COP26, and becoming a recognized solution to the problem of retrofitting the world’s existing housing stock. Single family homes perhaps represent the most challenging building type to retrofit, to meet a net zero goal. This program developed by Energiesprong is already demonstrating that their innovative combination that includes off-site construction, integration of components and digital customization CAN make retrofits fast, efficient and economical – so much so that the costs can be offset by the energy savings, and the inconvenience to homeowners is minimized.
The primary approach is to essentially ‘wrap’ the existing envelope with a new, highly insulated, air-tight assembly, including new high performance windows and doors. It allows all work to be done from the exterior, meaning the insulation and air barrier layers are continuous, and the inhabitants and interior finished do not need to be disturbed. We’ve known for some time that this method is ideal, but what we struggle with is the obliteration of the sometimes cherished, sometimes protected exterior that we may be loath to give up. It’s an issue I’ve been grappling with for sometime, myself, especially coming from a background that has included historic preservation and restoration work.
Given the urgency of the situation we are in now, however, I believe we need to embrace this approach, except for some very special cases where the building exterior has real historic significance. The options for re-cladding the new insulated envelope have progressed significantly in the past few years as well, so the new exterior finishes can be designed with as much variety and thoughtfulness that exist today. Of particular interest is ‘Thin Brick’, which can be installed as a relatively lightweight veneer over rigid insulation, with corner units that imitate traditional brick. On the more technical side, there are more options for thermally isolated connectors to support the exterior finish, and integrated insulated sheathing products that reduce the cost and labour for installation.
