Who this guide is for
- Homeowners with high bills or uneven comfort
- People planning insulation or envelope upgrades
- Anyone wanting a prioritised list of efficiency improvements
- Owners preparing for a phased efficiency programme
What an energy audit looks at
A thorough audit considers the whole home as a system: where air leaks, how well it is insulated, how it ventilates, and how heating and cooling perform together. Specialists may use a blower-door test to measure leakage and thermal imaging to reveal cold spots.
Understanding the scope helps you ask for the right assessment and interpret what comes back.
- Air leakage through gaps and the envelope
- Insulation coverage and weak points
- Ventilation and moisture behaviour
- Heating and cooling performance as a system
Gather information beforehand
An assessor works faster and more accurately when you arrive with context. Note the rooms that feel cold, draughty, or stuffy, when discomfort is worst, and any past upgrades or known issues.
Documenting symptoms turns your lived experience into useful evidence rather than leaving the assessor to discover everything cold.
- List rooms that are cold, draughty, or stuffy
- Note when problems are worst and in what weather
- Record past upgrades and any known issues
- Have access ready to lofts, basements, and service areas
Be present and ask questions
Following the assessor where appropriate, and asking why each finding matters, helps you understand the report later. Good questions focus on cause, priority, and how findings relate to comfort, not just energy.
An audit that you understand is far more useful than a document you file away.
Turn findings into a phased plan
An audit typically produces a list of opportunities. Resist doing everything at once; prioritise by impact, dependency, and disruption, and route the actual work to qualified installers.
Some measures interact, so sequence matters. Sealing and insulating, for example, change how a home ventilates, which is itself an area for professional judgement.
- Prioritise findings by impact and dependency
- Sequence measures that interact with each other
- Route the work to qualified installers
Energy audit preparation checklist
- 1Confirm what the audit will cover
- 2List rooms with comfort or draught problems
- 3Note when issues are worst and in what weather
- 4Record past upgrades and known issues
- 5Clear access to lofts, basements, and service areas
- 6Prepare questions about cause and priority
- 7Plan to act on findings in phases
- 8Route any resulting work to qualified professionals
Common mistakes to avoid
- Treating the audit as a verdict rather than a starting plan
- Arriving with no notes on where the home is uncomfortable
- Blocking access to lofts, basements, and service spaces
- Acting on findings in a random order
- Ignoring how sealing and ventilation interact
- Attempting recommended upgrades without qualified installers
When to involve a professional
- The audit itself should be carried out by a qualified energy assessor.
- Insulation, ventilation, and envelope work should be handled by qualified professionals; requirements vary by location.
- Sealing a home changes ventilation needs, which requires professional judgement.
- Costs and timelines for resulting upgrades vary by home and scope.
Frequently asked questions
Questions readers ask about this topic
What does a home energy audit actually involve?
A qualified assessor reviews the home as a system, looking at air leakage, insulation, ventilation, and heating performance, sometimes using a blower-door test and thermal imaging. The exact scope varies, so confirm what is included before booking.
How should I prepare for the visit?
Gather context: note which rooms are cold, draughty, or stuffy, when problems are worst, and any past upgrades. Clear access to lofts, basements, and service areas so the assessor can inspect them fully.
Should I do all the recommended upgrades at once?
Not necessarily. Prioritise by impact, dependency, and disruption, and remember that measures interact, sealing changes ventilation needs, for example. Phasing with professional input is usually wiser than tackling everything together.
Can I do an energy audit myself?
You can note symptoms and obvious draughts, but a thorough audit uses specialist tools and judgement best left to a qualified assessor. Your observations make their work more accurate rather than replacing it.
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