The physical installation may be short, but design, electrical coordination, equipment lead time and certification can take longer. A useful programme names dependencies rather than promising a single day.
The sequence
- Household brief and initial suitability check.
- Site survey, heat-loss or hot-water demand assessment.
- Written design and fixed scope.
- Permissions, network or building-control steps where applicable.
- Equipment ordering and confirmed delivery.
- Removal and enabling work.
- Plumbing, electrical and control installation.
- Commissioning, certificates and user handover.
- First-week performance review.
Find the critical dependency
An incoming-supply change, listed-building consent or unavailable product can control the date. Do not remove working equipment until key parts and responsible trades are confirmed.
Plan loss of service
Ask how long hot water and heating will be off and what happens if commissioning runs late. Winter whole-home work needs a practical contingency.
Protect the house
Confirm access, floor protection, dust, water isolation, parking, waste removal and making good. Large units may need a surveyed route and lifting plan.
Handover is part of installation
Allow time to demonstrate controls, boost, isolation, fault contacts and tariff scheduling. Do not schedule handover for the moment the last trade intends to leave.
Your next step
Ask for a dated programme showing who owns each dependency and the last safe point to cancel existing equipment removal.
Sources
Primary and independent references checked by our editorial team.
- Installing renewable technology at home — Energy Saving Trust Checked 10 Nov 2026
- Before you get work done on your home — Citizens Advice Checked 10 Nov 2026