New Build & Snagging
New builds can be cold, draughty or damp when the airtightness, insulation or ventilation was not built as designed. Testing proves the defects for a snagging claim.
Why is my new build cold or draughty?
A new build that feels cold or draughty is almost always a sign that the airtightness or insulation was not built as it was designed. On paper the home should perform well; in reality, gaps in the air barrier, missing or compressed insulation and thermal bridges at junctions are common defects that let heat out and cold air in. Because these are buildability and quality issues, they can usually be proven by testing — and that evidence is what supports a snagging claim.
Read the guideWhy does my new build have condensation or damp?
New builds often suffer condensation and damp in their first year or two for reasons specific to new construction: the building materials are still drying out, the home is built airtight, and the ventilation that should remove the moisture is frequently missing, undersized or simply switched off. Combine a lot of moisture with a tight envelope and inadequate ventilation and humidity rises, condensing on cold surfaces. It is a ventilation and build-moisture problem, not necessarily a fault in the structure.
Read the guideShould I get an air test or survey on my new build?
If your new build is cold, draughty, or prone to condensation, an independent air test and performance survey is well worth it, because it provides objective evidence of whether the home was actually built to the airtightness, insulation and ventilation it was designed and sold with. New builds are tested at handover, but that single result does not always reflect how the finished home performs, and an independent survey can measure it, locate the defects, and give you the documented proof needed for a snagging or warranty claim.
Read the guideWhy is my new build too hot in summer?
New builds frequently overheat in summer for reasons built into modern design: large areas of glazing that admit a lot of solar gain, often with little or no external shading; high airtightness and insulation that, while excellent for winter, also keep heat in; limited openable windows or restricted night ventilation, especially in flats; and compact, well-sealed layouts that trap internal gains. The combination means heat gets in and cannot easily get out — but it is a design-and-ventilation problem that can be managed with shading and better purge ventilation.
Read the guideCan I claim against my developer for a cold or damp new build?
If a new build is persistently cold, draughty or damp, you may well have grounds to raise it with the developer or warranty provider — but a claim succeeds on evidence, not on how the home feels. The decisive question is whether the property was actually built to the design and the standards it was sold against: whether the insulation, airtightness and ventilation are genuinely as specified, or whether defects in workmanship have left the home under-performing. That is a measurable matter. A performance investigation — airtightness testing, thermal imaging and moisture and ventilation assessment — turns a subjective complaint of a cold or damp house into documented proof of where and how the build falls short, which is what a developer or warranty body will respond to.
Read the guideWhy does my new build feel stuffy or have poor air quality?
A new build that feels stuffy, humid or 'airless' is showing the consequence of a very common situation: modern homes are built airtight to save energy, which is good, but that airtightness only works if the ventilation designed to go with it is installed and properly commissioned — and very often it is not. An airtight home with under-performing ventilation cannot bring in enough fresh air or remove moisture and pollutants, so it feels stuffy, gets humid, and can develop condensation and poor indoor air quality. The unit may be present but never balanced, or the extract simply too weak. It is a ventilation defect, and it is both fixable and, where the home is in warranty, something the developer should put right.
Read the guideWhy is my new-build warranty not covering damp?
Many homeowners find their new-build warranty rejects a damp or mould claim on the grounds that it is 'condensation' or caused by their 'lifestyle' rather than a building defect — a frequent and frustrating outcome. Warranties typically exclude condensation and routine maintenance, so developers and warranty providers lean on that exclusion, attributing damp to how the home is used. But condensation in a new build is very often the symptom of a genuine defect — inadequate ventilation that was never properly installed or commissioned, missing or bridged insulation creating cold spots, or airtightness and thermal-bridging failures. Independent evidence is what reframes the problem from blamed lifestyle to provable defect, which is the basis of a successful claim.
Read the guideHow do I prove my new build is underperforming?
Proving that a new build is underperforming — cold, draughty, damp or expensive to run despite its modern specification — means measuring how the home actually behaves and comparing it with how it was designed and certified to perform. Subjective complaints ('it feels cold', 'the bills are high') are easy for a developer to dismiss; measured evidence is not. The tests that build a credible evidence pack are an airtightness (blower door) test against the design figure, thermal imaging against the insulation specification, ventilation flow measurement against the design rates, and humidity and temperature logging. Together they show whether the home was built as designed, which is the basis for a snagging or warranty claim.
Read the guide