The complex interaction of the 4 key principles (insulation, airtightness, continuity of insulation, and ventilation) means that the order in which home improvements are undertaken is very important. It helps if you think of your home as a complex system which needs to be considered as a whole. Piecemeal improvements to a home, without fully considering the 4 principles, can result in ‘unintended consequences’ (see previous blog). To avoid this, it is very useful to think about a ‘whole house plan’ before you begin any refurbishment work.
What is a whole house plan?
A whole house plan is an energy efficiency improvement strategy for the entire house, ideally based on good or best practice approaches. This is the plan that, if funds were allowing, you could undertake for your home to make it warm, comfortable and energy-efficient. If budgets are tight, there are smaller, easier stages that can be undertaken first but it is useful to keep your whole house strategy in mind when undertaking any improvement works on your home. For example, it is possible to implement internal wall insulation improvements on a room by room basis at the same time as when you are upgrading your kitchen/ bathroom etc. You could tackle the floor, walls, ceilings, windows within the room, taking into account the 4 principles. You would just need to think ahead and consider how the work would join up with the next room (eg ensuring continuity of insulation).
Joined up thinking
If you don’t map out a ‘whole house plan’ there is a danger that you will undertake works on your home which would later need to be removed if you wanted to do further energy efficiency improvements. For example if a new kitchen is installed, without thinking about energy efficiency measures, it might close off the possibility of any further improvements to that room. Similarly, if you have installed a small amount of external wall insulation, you are unlikely to want to upgrade the external insulation to a greater thickness anytime soon.
Be the best you can
With your whole house plan in mind, you might, for example, decide to build a new extension or install triple glazed windows with higher energy efficiency standards than the rest of the house. This will obviously be dependent on budget (and projected budget into the future) but wherever possible we would urge you to ‘be the best you can’ with any home improvements.
Houses can be very different. Assessing a house for a low energy refurbishment is both an art and a science and needs a good understanding of construction, local conditions and energy efficiency. If you are considering getting an energy assessment of your home, be aware that quick, superficial energy assessments are unlikely to give specific enough advice for your home. For radical refurbishments , the Passivhaus methodology (using specialist PHPP software) offers the most efficient and reliable approach currently available for predicting energy use in very low energy homes.
Chayley Collis, Communications Manager, Green Building Store