What order should I do things when renovating?

Planning renovations in a practical sequence helps avoid costly mistakes, missed opportunities for energy-savings and unintended consequences.

Carrying out energy efficiency upgrades in the right order is essential for good and healthy outcomes. Planning retrofit/renovation works in a practical sequence helps avoid unnecessary costs, unintended consequences and missed opportunities for carbon and energy savings.

Designing the plans around the whole house

Every home is different. A whole house approach means considering a building as a complete system in its construction, condition, location, and orientation, alongside who lives there and how they use it. The fabric (walls, roof, windows, floors and doors) and the services (heating, hot water, ventilation, lighting) all interact with one another and with the people living in the home.

Installing measures in isolation can lead to poor results. For example, installing insulation without accounting for ventilation can result in damp and mould. Likewise, investing in a new heating system before reducing heat demand may lead to inefficiency and high energy bills.

In short, retrofit renovations should be designed around the specific building and household, not a checklist of generic improvements.

Reduce heat-loss first, upgrade systems second

The ‘fabric first’ principle prioritises reducing energy demand by improving the thermal envelope of a building before upgrading heating systems or adding renewables. It’s a valuable approach in many cases as it aids in reducing bills, improving comfort and supporting the efficiencies of low-carbon technologies like heat pumps.

However, it’s no longer always the most appropriate first step. Advances in heat loss calculations and the decarbonisation of the electricity grid have changed the picture. For example, in many homes, a heat pump may now be feasible with only modest fabric upgrades. And in some cases, the carbon payback for major insulation work (especially where high embodied carbon materials are used) is slower than it used to be.

So, reducing demand is still important, but not always the logical or necessary first action. Practicality, cost, disruption and carbon impacts must also all be considered.

The ‘Energy Hierarchy’

The energy hierarchy remains a helpful principle:

1. Reduce energy use
2. Improve efficiency
3. Use renewables

However, in practice, retrofit renovations do not always follow this order. A rigid interpretation can hold back progress, especially where funding, technical constraints or specific household needs point to a different priority.

A good retrofit plan uses the hierarchy as a framework, not a fixed pathway.

Family of a man, woman and toddler gathered around a tablet in their home, mid-renovation.

A sensible sequence

Although every home will differ, a well-considered home project often follows this general order:

Repair and maintain the building – Address damp, structural issues and ventilation first to ensure the home is in a good state before any upgrades begin.

Develop a whole house plan – Use an energy assessment to understand the building’s current performance and what upgrades are practical in each context.

Implement low-cost, low-risk improvements – Measures like draughtproofing and heating controls offer immediate benefits with minimal disruption.

Carry out fabric improvements where appropriate – Loft insulation, cavity wall insulation and floor insulation are good investments where technically suitable and installed correctly.

Review heating and hot water systems – Once energy demand is reduced, heating and hot water system sizing can be optimised. This is the right stage to consider a low carbon option such as a heat pump.

Explore renewables – Solar PV or thermal systems may complement other measures but are rarely the first priority.

A nuanced approach

While principles like ‘fabric first’ and the ‘energy hierarchy’ remain useful, they must be applied flexibly with a clear understanding of the property, the household, the occupancy and the wider context.