Window & Door Building Control Checklist

This page is a printable one page checklist and gives builders a checklist to print, save and forward.

Before You Order

  • Confirm which Building Regulation standards apply to the project.
  • Obtain the architect’s latest window/door schedule.
  • Confirm required whole-window Uw values.
  • Confirm required door Ud values where specified.
  • Obtain any Part O maximum g-values.
  • Obtain acoustic requirements such as Rw / Rw + Ctr.
  • Obtain ventilation schedule.
  • Identify PAS 24 / Part Q requirements.
  • Identify escape windows.
  • Identify safety-glazing locations.
  • Identify fire-rated windows and doors.
  • Confirm finished floor levels.
  • Confirm threshold/access requirements.
  • Check structural/wind-load requirements for unusually large products.

Part L – Energy

  • Check the required Uw/Ud values.
  • Ensure supplier is quoting whole-product performance, not merely centre-pane glass.
  • Confirm glass Ug where needed.
  • Confirm spacer and glass build-up.
  • Keep thermal calculations/product evidence.

The applicable Approved Document L edition depends on the project’s regulatory status; 2026 standards take effect from 24 March 2027 subject to transition arrangements.

Part F – Ventilation

  • Identify ventilation system.
  • Confirm whether background ventilators are required.
  • Check required equivalent areas.
  • Identify acoustic ventilator requirements.
  • Do not use night-vent positions as a substitute.
  • Don’t remove required ventilation because the customer dislikes vents.
  • Record wall-vent alternatives where applicable.

Government Part F guidance confirms wall background ventilators can provide an acceptable route where they provide the appropriate equivalent area.

Part Q / PAS 24

  • Identify accessible windows and doors.
  • Check exact PAS 24 configurations.
  • Verify maximum sash/door sizes.
  • Check glazing specification.
  • Check handles/locks/cylinders.
  • Check threshold configuration.
  • Obtain supporting evidence.
  • Do not make unsupported hardware changes after manufacture.

Part Q applies to new dwellings and relevant dwellings formed by material change of use.

Part O – Overheating

  • Obtain overheating assessment.
  • Check g-values by elevation.
  • Check light transmission if specified.
  • Identify large south/west glazing.
  • Check opening requirements.
  • Coordinate restrictors with overheating strategy.
  • Check external shading requirements.

Part O currently applies to new residential buildings.

Part B – Fire Safety

  • Mark every escape window.
  • Check unobstructed clear opening.
  • Specify egress hinges where required.
  • Check finished floor/opening height.
  • Identify fire-rated windows.
  • Identify fire-rated doors.
  • Confirm exact classification – E/EI/EW/REI etc.
  • Check maximum fire-system dimensions.
  • Confirm supporting wall.
  • Follow fire-stopping details.
  • Photograph installation before covering fire-stopping.

Part K – Safety

  • Mark door glazing.
  • Mark sidelights.
  • Check glazing below critical heights.
  • Check finished floor level.
  • Specify suitable safety glass.
  • Confirm permanent glass markings.
  • Check guarding/falling requirements.
  • Check restrictors.
  • Check manifestation where applicable.

Part K is the current Approved Document covering protection from falling, collision and impact, including glazing safety.

At Survey

  • Measure brick openings.
  • Record internal/external finished floor levels.
  • Check cills.
  • Check structural supports/lintels where relevant.
  • Record existing ventilation.
  • Mark escape windows.
  • Mark low-level glazing.
  • Record door opening direction.
  • Check threshold details.
  • Photograph every opening.

On Delivery

  • Check quantities.
  • Check sizes.
  • Check damage.
  • Check glass markings.
  • Check colours.
  • Check hardware.
  • Check PAS 24/security items.
  • Check fire labels/product identification.
  • Photograph damage before installation.

During Installation

  • Install frames square, level and plumb.
  • Use appropriate fixings.
  • Follow manufacturer fixing centres.
  • Pack correctly.
  • Maintain correct frame tolerances.
  • Insulate perimeter appropriately.
  • Weather-seal externally.
  • Airtight-seal internally where specified.
  • Follow fire-system installation instructions.
  • Do not make unsupported modifications.

Before Building Control Inspection

  • Test all windows.
  • Test all doors.
  • Check escape windows.
  • Check restrictors.
  • Check vents.
  • Check safety glass markings.
  • Check thresholds.
  • Check closers.
  • Check fire-door operation.
  • Check seals.
  • Have compliance documentation available.

Handover File

Keep:

  • Window/door schedule
  • Final specification
  • U-value evidence
  • Glass specification
  • PAS 24 documents
  • Ventilation information
  • Fire documents
  • Installation instructions
  • Site photographs
  • Completion/sign-off documentation

Trade Tech Tip

The biggest mistake isn’t fitting the wrong product.

It’s often ordering the wrong product because nobody collected the technical information before manufacture.

Use this checklist at quotation stage, not just at Building Control inspection.