Airtightness Conversation Preparation Checklist

Walk each room on a windy day and note where you feel air moving, naming the wall, opening or fitting rather than simply naming the room.

A professional can act on the loft hatch in the back bedroom, but not on a report that the back bedroom is draughty.

Record which wind directions make each draught worse, since a draught that appears only in one wind usually points somewhere specific.

Direction dependence narrows the search enormously and is something only the occupants can supply.

Note whether draughts are felt at floor level, at head height or around openings, and describe the sensation without naming a cause.

Height is one of the few clues an occupant can record reliably, and describing it without proposing a cause keeps the observation useful.

Write down which rooms are hard to heat compared with others of a similar size in the same property, and how quickly they cool down.

Comparing rooms within one building removes most of the variables, which makes the comparison more informative than any single room described alone.

Note whether curtains, blinds or the loft hatch move when doors are opened or when an extract fan is running.

Movement in one place when air is pulled from another shows that the two are connected, which is exactly what a designer wants to know.

Record whether the property feels different when the heating is running, since some air movement is only noticed once warm air is circulating.

List every fan outlet, vent, flue, cooker hood grille and air brick you can see on the outside of the building, and mark where each one sits.

An external walk round finds openings that were forgotten indoors, including some no longer connected to anything.

Note where water, electricity, gas, telecoms and drainage enter the building, and photograph where each passes through the wall or floor.

Do not disturb or seal around any service entry yourself; each of these belongs with the relevant qualified trade.

Record where the loft hatch is and describe how it closes, since hatches are a common route for warm air to leave the heated part of a home.

Hatches are straightforward to address and are routinely left out of a sealing scope simply because nobody claims them as their own.

Note any downlights, extract grilles, speakers or other ceiling fittings in a ceiling that sits below a loft or an unheated void.

Fittings in that particular ceiling are openings between heated and unheated space, and they are usually installed by someone with no sealing brief.

Write down whether there is a cat flap, letterplate, disused flue, old waste outlet or redundant vent anywhere in the outside walls or roof.

Redundant openings are frequently missed because nobody thinks of them as part of the building any more.

Note where pipes or cables run into cupboards, under a bath or behind kitchen units, since these routes are out of sight and rarely surveyed.

Look but do not open up boxed areas yourself; ask a qualified professional to examine anything that needs dismantling.

Ask where the sealing line is intended to run between the new work and the existing building, and ask to see it marked on a drawing.

A line that cannot be drawn usually cannot be built, and asking to see it is the single most useful question here.

Note where each floor meets an external wall in the property, since this junction sits behind skirtings and is hard to examine or reach later.

This junction is buried by the time anyone thinks about it, so raising it while floors and skirtings are still open is the only practical moment.

Ask how the sealing line is intended to pass around window and door openings, and which trade is responsible for that part of it.

Openings are where the sealing responsibility usually changes hands, which is why they leak.

Record where a stair, chimney breast or shared wall interrupts a floor or ceiling, and raise each of them as a separate junction question.

Work at a shared wall may involve your neighbour and specific local requirements; confirm what applies before anything is agreed.

Ask what happens where the walls meet the roof at the eaves and at the gable, and which trade carries out the sealing at those points.

The eaves are where the wall trade stops and the roof trade begins, which is precisely why the line so often stops there too.

Note where an extension, conservatory or earlier addition joins the original building, and photograph the junction inside and outside.

Joins between construction of different ages are among the most consistently leaky parts of a home.

Ask who is responsible for the continuity of the sealing line across all trades, and record that role in the written scope you agree.

Without a named role, sealing becomes everyone and therefore nobody, which is the usual reason results disappoint.

Ask at what point the sealing work would be looked at before it is covered by plasterboard, insulation or finishes.

Once a sealing line is covered it can rarely be examined again without opening work up; agree the moment to look with the professional involved.

Write down which trades will make new holes after the sealing work is finished, and ask how each of those holes would be dealt with.

Aerial fitters, alarm installers and kitchen fitters commonly arrive after sealing and undo it without anyone noticing.

Ask whether the electrician, plumber and kitchen fitter have been told about the sealing intention before they begin their work.

Trades who know the intention route their services differently, which is far more effective than sealing afterwards.

Record whether parts of the work are being carried out by different contractors under separate agreements, since the joins between them need naming.

Where two agreements meet there is usually no named owner of the sealing line, and that gap is invisible until somebody looks for it.

Agree in writing how a problem found after completion would be traced back and who would be responsible for putting it right.

Ask what the ventilation intention is for the property once sealing work has been done, and insist the two subjects are discussed together.

Sealing without a ventilation plan belongs with a qualified professional to resolve; never treat the two as separate pieces of work.

Note every open fire, stove, boiler or other appliance that burns fuel in the property, and record where each of them takes its air from.

Any appliance that burns fuel must be raised with a suitably qualified installer before sealing work is planned around it.

Record which windows have vents built into their frames and whether the household normally keeps those vents open or closed.

Vents that are habitually closed tell you something about noise, draughts or habit that the design should take account of.

Write down where laundry is dried and where cooking steam currently goes, so the effect of sealing on those rooms is discussed rather than discovered.

Moisture that used to escape through leaks has to go somewhere once the leaks are closed.

Ask what would replace any air brick or vent that sealing work would close, and never assume one can simply be blocked up.

Existing vents may serve a floor void, a flue or an appliance; only a qualified professional should decide whether one can be closed.

Note whether anyone in the household is sensitive to stuffiness, cold draughts or humid air, and record that as an input to the discussion.

How the building will be lived in shapes what a ventilation intention has to achieve, and it rarely reaches the designer unless it is written down.

Note the age of the property as far as you know it and how the walls appear to be built, describing what you can see rather than concluding.

Age and construction change the approach fundamentally, and an honest description is more useful than a confident guess.

Ask whether this construction is one that needs to let moisture move through it, and what that means for the sealing decisions being proposed.

Whether a construction needs to remain open to moisture is a specialist judgement; do not settle it from general reading.

Record where damp marks, salt deposits or peeling paint appear now, and raise every one of them before any sealing work is agreed.

Existing moisture must be understood by a qualified professional before sealing is planned, since sealing can change how it behaves.

Note whether the ground floor appears to be suspended timber with vents around the outside walls, and ask what sealing would mean for that air path.

The ventilation path beneath a suspended floor is easy to interrupt and difficult to restore.

Ask what the consequences would be of sealing one part of the building and leaving the rest as it is, and record the answer.

Partial work is the normal situation rather than the exception, and the boundary between treated and untreated fabric deserves discussing openly.

Write down anything you know about earlier insulation or sealing work at the property, including anything that was later removed or abandoned.

Previous work often explains present behaviour, and its edges are frequently where problems concentrate.

Ask whether a test is intended, at what stage it would happen, and what would be done if the result is not what was hoped for.

A test late in the work leaves no opportunity to act on it, which is why the stage matters more than the test itself.

Ask who arranges any retesting if it is needed, and how that is written into the agreement rather than left to goodwill.

Record what you want a test to tell you, since producing a figure and finding out where air moves are different purposes.

Owners usually want the leaks found, while the paperwork usually wants a figure, and the two need stating separately.

Ask whether smoke, thermal imaging or another method would be used to find where air is moving, and who interprets what it shows.

Interpretation of imaging or smoke testing needs a qualified professional; images on their own are easy to misread.

Write down whether you want to be present during testing and what you would like to be shown while the building is under pressure.

Being shown the leaks in person is far more useful to an owner than reading about them afterwards.

Ask what documentation you would receive afterwards and where it should be kept with the rest of the property records.

Testing paperwork tends to disappear between parties, and agreeing where it lands keeps it available to whoever works on the building next.