Part L photo evidence checklist for UK builders
6 min read
Most evidence disputes happen because a photo was never taken, or because nobody can prove where and when it was taken. This checklist walks the five core stages of a typical UK dwelling and sets out what to capture at each one.
1. Substructure and foundations
Photograph the excavation before concrete, with a measuring staff or tape visible for depth. Include the trench sides, any step in level and the bearing stratum.
Capture reinforcement and any founding on made ground or near trees, plus the poured concrete before the next lift covers it.
2. Damp proofing and ground floor
Show the DPC continuous around the perimeter, its lap to the damp proof membrane, and the height above finished ground level.
Photograph the insulation layer under the slab or between joists, with the product label visible where possible, and any service penetrations sealed.
3. External walls and cavity insulation
Capture insulation boards or batts fully filling the cavity, with tight joints and no gaps at reveals, cills, lintels and floor junctions.
Photograph cavity trays, weep holes, wall ties at correct spacing and the closing of cavities at openings — these are the details most often questioned later.
4. Roof structure and membrane
Show truss or rafter fixings, bracing and strapping to the wall plate before boarding out.
Photograph the underlay laps, ventilation at eaves and ridge, and insulation continuity where the roof meets the wall to prove the thermal line is unbroken.
5. First fix services
Capture cable and pipe routes, notching and drilling in joists, and fire stopping or sleeving where services cross compartments.
Photograph airtightness detailing around penetrations before plasterboard goes on — this is the single hardest thing to prove afterwards.
What every photo should carry
The stage it belongs to, the location of the plot, and the date and time it was taken. Without those three things a photo is only a picture.
TotalCertify writes all three into the image as you capture it, so the evidence cannot be separated from its record.