The right time for heat pumps in retrofit

The Right Time for Heat Pumps: Decarbonising Home Heating in a Staged Retrofit
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A new research report by Sustainable Buildings Alliance member the Passivhaus Trust examines the question of the right time to install a heat pump in existing homes. Decarbonising home heating is an urgent priority, and heat pumps are a fast way to reduce emissions, but are they sufficient, and how should they be combined with fabric improvements?

In this paper, the Passivhaus Trust puts forward a “people first” approach – arguing that enabling heat pumps and fabric to work in synergy to maximum effect could deliver, not only fast decarbonisation and optimum lifetime carbon savings, but also better housing that is healthier, more comfortable, and cheaper to run.

Focusing on a step-by-step retrofit approach, the paper explores in detail the implications of installing an air source heat pump at different levels of fabric improvement by modelling some typical retrofit scenarios, both “light” and “deep”, using PHPP to estimate energy demand and hence running costs. It addresses the question “when should you install a heat pump in a staged retrofit?”, and thereby aims to help clients and designers to make informed decisions in developing an optimum retrofit plan.