What is the Energy Hierarchy?

Reduce first, then be efficient, then add renewables. The energy hierarchy is the logic behind Part L, planning policy, and every sensible low-energy design.

— reviewed against the regs as they stand.

The principle

The energy hierarchy ranks the ways to cut a building’s carbon footprint, in order of preference:

  1. Reduce energy demand — fabric first: insulation (u-values), air tightness, minimised thermal bridging, good form and orientation.
  2. Use energy efficiently — efficient heating systems and controls, MVHR, LED lighting, waste water heat recovery.
  3. Supply from low-carbon and renewable sources — heat pumps, solar PV, solar hot water.

London plans phrase it as “be lean, be clean, be green” — and many Local Planning Authorities structure their energy statement requirements around exactly this logic, expecting demand reduction to be demonstrated before renewables are counted.

Why the order matters

A kilowatt-hour you never need is cheaper than one you generate. Fabric measures are permanent, maintenance-free and invisible to occupants; renewables degrade, need replacing, and underperform on poorly designed buildings. Part L embeds the same thinking through the fabric energy efficiency target, which renewables can’t satisfy.

It’s also why we push calculated junction Ψ-values so hard: they’re a step-1 improvement that costs nothing on site.

Planning asking you to show the hierarchy?

Send us the condition wording and your drawings. We'll produce the energy statement that answers it, and tell you first whether your design gets there as drawn.

Get an energy statement quote or call 01202 623236