Retrofit designed on measured data — and verified at the end.
Retrofit done badly imports damp. We provide the measured baseline, the moisture-safe design discipline and the verification that turn a fabric upgrade into a provable improvement rather than a hidden liability.
Retrofit is the UK's biggest lever for carbon and comfort — and its biggest source of unintended consequences. Add insulation without managing airtightness, thermal bridging and ventilation and you can move the dew point into the structure, creating interstitial condensation and mould you cannot see. We apply the Passive House and PAS 2035 discipline to any retrofit, large or small: assess, model, design as one system, sequence safely, and verify by measurement.
The challenges we solve
- Solid-wall homes where IWI must be hygrothermally modelled to be safe.
- Tightening the envelope without upgrading ventilation — the classic mould-causing error.
- Thermal bridges at junctions, reveals and floor edges undermining the headline U-values.
- No measured baseline, so improvement can never be proven to clients or funders.
- Sequencing trades so the air barrier and ventilation are actually continuous and commissioned.
How RetrofitIQ supports you
Pre-retrofit diagnostic baseline
Thermal imaging, blower-door testing and moisture logging to establish exactly how the building performs before works begin.
Moisture-safe design & modelling
WUFI/Glaser hygrothermal modelling and thermal-bridge-free detailing so the fabric strategy is provably safe.
Fabric-first sequencing
'Fabric first, plant last' and 'build tight, ventilate right' applied to the works programme and trade sequence.
Post-works verification
Re-test ACH₅₀ and re-image the fabric to prove the design intent was delivered.
- Measured pre-retrofit baseline report
- Hygrothermal model output for insulation build-ups
- Continuous air-barrier and ventilation strategy
- Sequenced, moisture-safe works plan
- Verified before-and-after performance data
Common questions
Do I need a blower-door test before retrofit?
For any serious retrofit, yes. Without a measured airtightness baseline you cannot design the air barrier rationally, size ventilation, or prove the improvement afterwards.
Can you both design and carry out the works?
Yes — we Investigate, Diagnose, Design, Remediate and Verify. One accountable team avoids the gaps between designer, installer and tester where retrofit usually fails.
Is this only for whole-house projects?
No. The same discipline applies to a single solid wall or a loft. The principle — model and verify, never assume — scales up and down.
Investigate → Diagnose → Design → Remediate → Verify
RetrofitIQ is not only a diagnostics company. We take projects from first investigation through to verified improvement — and you decide how far we go. Engage us for an investigation on its own, an investigation plus targeted remedial works, or a complete building-performance and retrofit project.
A measured diagnosis — thermal imaging, blower door testing, moisture and building-physics analysis — with a clear, costed report you can act on however you choose.
We investigate, then carry out targeted remedial works — airtightness, insulation, ventilation or thermal-bridge corrections — and verify the result.
A full fabric-first, Passive House-informed retrofit from diagnosis through design, installation and verification — one accountable team, one point of responsibility.
- Airtightness improvements & draught-proofing
- Internal wall insulation (IWI)
- External wall insulation (EWI)
- Loft & roof insulation
- Suspended floor & underfloor insulation
- Thermal-bridge detailing & correction
- Extract ventilation & MVHR installation
- Soundproofing & acoustic upgrades
- General building-fabric improvements
See a sample 2D thermal-bridge report
A worked ceiling-to-wall junction — existing vs improved detail, isotherms, surface temperatures, dew-point and condensation-risk verdict, and the thermal-bridge reduction. See exactly how we model and predict performance before work begins.