Top 10 Defects Found During Apartment Handover Inspections

An apartment snagging inspection consistently turns up a distinct set of defects that go well beyond the paint drips and scuffed skirting boards found in a typical house snagging survey, because a flat sits inside a shared building with its own fire doors, party walls, and communal services to get wrong.

Why Apartment Handover Inspections Differ from House Snagging

A house snagging inspection is concerned almost entirely with a single, self-contained dwelling. An apartment handover inspection has to account for that same dwelling plus a layer of shared building elements that a house simply doesn’t have: fire-compartmented corridors, separating walls and floors between neighbouring units, communal ventilation and service risers, and shared entrance doors and lobbies. A new build apartment inspection therefore needs a checklist that covers both categories, since many of the shared elements are life-safety systems rather than cosmetic finishes.

It is also worth being clear from the outset about responsibility, which is somewhat more layered for a flat than a house. Defects inside the demise of the flat itself are typically the developer’s responsibility to fix under the standard builder warranty period — usually two years of direct builder responsibility followed by a longer structural warranty of around ten years from providers such as NHBC, LABC, or Premier Guarantee. Communal-area defects are also generally still the developer’s responsibility during that same warranty period, but depending on the stage of the development and the ownership arrangements in place, responsibility can also sit with an employer’s agent, a management company, or the warranty provider once day-to-day maintenance has transferred away from the builder.

The Top 10 Defects Found During Apartment Handover Inspections

1. Flat entrance fire doors that fail to self-close and latch

A flat entrance fire door only works as intended if its self-closing device reliably pulls the door fully shut and the latch engages every time. Inspectors commonly find self-closers that have been disabled, adjusted incorrectly, or fitted with the wrong closing force, leaving the door either failing to latch or slamming so hard that residents prop it open — both of which defeat its purpose in a fire. This is one of the most frequently flagged items on any apartment defects checklist, precisely because it is quick to check and easy to get wrong.

2. Excessive or uneven gaps around fire doors

A fire door depends on a consistent, tightly controlled gap between the leaf and the frame to perform as tested. UK guidance generally allows no more than around 4mm at the head and sides, with a wider gap — often up to 8–10mm — permitted at the threshold depending on the specific tested door assembly, though the precise figures always depend on the manufacturer’s certification for that door set rather than a single universal rule. Handover inspections frequently find gaps that exceed these tolerances or are uneven around the door’s perimeter, which can prevent intumescent and smoke seals from closing the gap quickly enough in a fire.

3. Missing or incomplete fire-stopping around service penetrations

Where pipes, cables, and ducts pass through a fire-rated wall or floor — including where a soil vent pipe stack rises through separating floors between flats — that penetration has to be sealed with a fire-stopping system that restores the wall or floor’s fire resistance. Crucially, fire-stopping only performs as intended when installed as a certified system according to the manufacturer’s tested specification; generic sealant or expanding foam packed around a pipe does not maintain a fire rating even though it may look sealed. This is one of the most consequential defects on this list because it is completely hidden once decoration is complete. A widely reported case at the Celestia apartment development in Cardiff found service penetrations with no fire-stopping applied at all, alongside door frames left unsealed against the surrounding wall — while not representative of every development, it illustrates how hidden passive fire protection defects can go undetected for years without independent inspection.

4. Failed or borderline pre-completion sound insulation tests

Under Approved Document E, separating walls and floors between flats must meet minimum airborne and impact sound insulation standards, verified through pre-completion sound testing carried out on a representative sample of dwellings across a development before it completes — the exact number of tests required depends on the size and construction type of the scheme rather than a fixed ratio. Common causes of poor results include gaps in the separating construction, rigid fixings that bridge between neighbouring flats, and incomplete sealing at the perimeter — issues that are difficult to fix retrospectively once finishes are in place.

5. Poor reverberation control in communal corridors and stairwells

Separately from sound insulation between flats, Approved Document E also requires common internal circulation areas — corridors, stairwells, and lobbies — to include acoustic absorption to control reverberation. Hard, untreated surfaces throughout a communal corridor can leave noise echoing and carrying further than intended, even where the sound insulation between individual flats is perfectly adequate.

6. Balcony and terrace waterproofing defects

Balconies and terraces rely on a continuous waterproof membrane with adequate falls toward a drainage outlet. Inspectors regularly find ponding water caused by inadequate falls, membranes that have not been properly turned up at doorways or thresholds, and drainage outlets that are undersized or poorly integrated with the membrane. A related and easily missed issue is a poorly detailed balcony threshold that creates a thermal bridge between the balcony structure and the internal floor, which can lead to both localised heat loss and condensation or damp at the threshold over time.

7. Ventilation and MVHR commissioning issues

Mechanical ventilation systems depend on air being able to move between rooms as well as being extracted to the outside, usually via transfer grilles or a door undercut sized for that purpose. A recurring issue found at handover is that door undercuts have been cut too tight, or a designed transfer air path has been blocked or omitted during fit-out, reducing airflow in exactly the rooms the system was designed to ventilate. Extractor fans that discharge into a roof or ceiling void instead of outside, and incompletely sealed ductwork, are further common findings.

8. Communal area finish and safety defects

Beyond the flat entrance fire doors, communal areas commonly show incomplete decoration and defects in the building’s wider fire and life-safety systems: smoke ventilation systems (AOVs) left uncommissioned or wired incorrectly, dry riser inlets and valves not properly installed or tested, access control doors that fail to secure properly, and emergency lighting that has not been commissioned or tested. Because these areas are shared, faults here are easy for an individual buyer to overlook, since no single flat owner considers the corridor “their” responsibility to check.

9. Kitchen and bathroom fit-out defects

As with houses, apartments commonly show incomplete grouting in tiling, sanitaryware that has not been properly sealed, aligned, or secured, and extractor fans in bathrooms venting into a void rather than to the outside. Incorrect falls on shower trays, leaking waste traps under sinks and baths, and loose or poorly fixed sanitary fittings are also frequent findings. These issues are less safety-critical than the fire and acoustic defects above but remain some of the most frequently reported snags overall.

10. External envelope, cladding, and window defects

Around windows and other openings in the external wall, missing or poorly installed flashings can allow water to track behind the cladding or render rather than being shed to the outside. On buildings with rainscreen or ventilated cladding systems, missing or incorrectly installed cavity barriers are a particularly serious defect, since these barriers are what stop a cavity behind the cladding acting as a chimney for fire to spread vertically or horizontally between compartments — an issue that received significant regulatory attention following the Grenfell Tower fire. Combined with gaps in sealant around window frames, these envelope defects are a common source of damp and, in the case of missing cavity barriers, a genuine fire-safety risk that only becomes apparent on close inspection.

Construction Moisture, Shrinkage, and Settlement Are Not the Same as Defects

New apartments often show hairline cracking in plaster, minor gaps opening up at joints between skirting and wall, or a period of noticeably higher humidity in the first few months after completion. Much of this is the ordinary result of construction moisture drying out of wet-trade materials such as plaster, screed, and masonry, combined with normal drying shrinkage as timber and other materials settle to their in-service moisture content. This is different from a genuine defect: it is expected, generally resolves on its own as the building dries out and settles over its first year or two, and is usually addressed with minor redecoration rather than a warranty claim. Buyers understandably sometimes treat this as a serious fault, but a professional snagging surveyor can distinguish ordinary drying-out effects from cracking or movement that points to an actual construction defect requiring repair.

Documents to Request at Apartment Handover

An apartment defects checklist should not stop at the physical inspection. Alongside the visual snagging survey, it is worth requesting the documentation that confirms the building’s key systems were actually tested and commissioned as designed. This typically includes:

• Confirmation of pre-completion sound test results for your unit type, where testing was carried out
• The Energy Performance Certificate (EPC) for the property
• The Electrical Installation Certificate (EIC) for the flat’s wiring, issued under BS 7671 by the installing electrician — not to be confused with an Electrical Installation Condition Report (EICR), which is a periodic re-inspection typically required only from around five years after the EIC was issued
• A Gas Safety Certificate from a Gas Safe registered engineer, where the property has a gas supply or gas appliances
• Ventilation or MVHR commissioning certificates confirming the system was tested and balanced after installation
• Fire door certification for the flat entrance door, where available from the developer
• Warranty documentation (such as the NHBC Buildmark policy) and any manufacturer warranties for major appliances
• Operation and maintenance (O&M) manuals for boilers, ventilation systems, and other key equipment
• Meter readings taken at the point of handover

What to Do If You Find These Defects During Handover

1. Record every defect in writing, with photographs, whether it sits inside your flat or in a shared area you have access to.
2. Report defects inside your own flat directly to the developer, as you would with a house, within the builder warranty period.
3. Report suspected communal-area defects — particularly fire doors, fire-stopping, and cavity barriers — to the developer in the first instance, since these are typically still within their construction warranty responsibility even though the managing agent will maintain them afterward.
4. Request the documentation listed above where it hasn’t been provided as standard, since missing or incomplete commissioning paperwork is itself worth flagging.

Summary

An apartment handover inspection has to look in two directions at once: inward, at the same finish and workmanship issues found in any new build flat defects list, and outward, at the fire doors, separating walls, cavity barriers, and communal services that only exist because the property sits inside a shared building. The most consequential defects on this list — failed fire doors, missing fire-stopping, missing cavity barriers, and inadequate sound separation — are also the easiest to miss, since they are concealed behind finishes long before a buyer ever sees the flat. A structured, independent apartment snagging inspection that checks both categories, and that requests the supporting commissioning documentation alongside the physical survey, gives a far more complete picture of what is being handed over at completion.

Frequently Asked Questions

What’s different about snagging a flat compared to snagging a house?

A snagging list for flats has to cover the same interior finish and fit-out issues as a house, plus a set of building-wide elements a house doesn’t have: fire doors, separating walls and floors between neighbouring units, cavity barriers behind cladding, and shared communal areas such as corridors and stairwells. These additional elements are often safety-critical rather than cosmetic, which changes how urgently they need to be reported.

Who is responsible for fixing defects found in communal areas?

Genuine construction defects in communal areas are normally still the developer’s responsibility to fix during the builder warranty period, in the same way as defects inside an individual flat. Depending on the stage of the development and the ownership arrangements in place, day-to-day maintenance and later reporting may instead involve an employer’s agent, a management company, or the warranty provider, rather than the developer directly.

What is pre-completion sound testing, and do I need to arrange it myself?

Pre-completion sound testing is testing required under Approved Document E to confirm that separating walls and floors between flats meet minimum airborne and impact sound insulation standards. It is arranged by the developer on a representative sample of dwellings across the development, not by individual buyers, though buyers can reasonably ask whether their unit type was tested and what the results were.

Should I get an independent snagging inspection before legal completion?

Where the developer allows access before completion, an independent apartment snagging inspection at that stage gives you the strongest position, since outstanding defects can be raised before you are legally committed to the purchase. Access before completion is at the developer’s discretion, and if it isn’t available, an inspection booked as early as possible after moving in is the next best option.

How many defects should I expect in a new apartment at handover?

Flats generally have fewer defects in total than larger detached houses simply because there is less floor area and fewer external elevations to inspect, but a meaningful number of snags at handover is still normal. The more important question is not the raw count but whether any of the defects found fall into safety-critical categories such as fire doors, fire-stopping, cavity barriers, or sound separation.

Can I inspect communal areas myself as part of my own snagging visit?

Yes, a buyer can and should visually check communal areas they have access to as part of a handover inspection, noting issues such as doors that don’t close properly, obvious gaps around door frames, or unfinished decoration. Some technical checks — confirming fire-stopping or cavity barriers behind a wall, or reviewing sound test results — are not visible without specialist access or documentation from the developer.