Understanding air leakage paths

To avoid air leakage in new dwellings it is necessary to know where leaks might occur.

Figure 2 shows the most common air leakage paths.

Many of the paths shown were found in the dwellings investigated in the Energy Efficiency Partnership for Homes study, referred to earlier. Here, they are examined in more detail.

Most common air leakage paths:

1 Underfloor ventilator grilles.

2 Gaps in and around suspended timber floors.

3 Leaky windows or doors.

4 Pathways through floor/ceiling voids into cavity walls and then to the outside.

5 Gaps around windows.

6 Gaps at the ceiling-to-wall joint at the eaves.

7 Open chimneys.

8 Gaps around loft hatches.

9 Service penetrations through ceilings.

10 Vents penetrating the ceiling/roof.

11 Bathroom wall vent or extract fan.

12 Gaps around bathroom waste pipes.

13 Kitchen wall vent or extractor fan.

14 Gaps around kitchen waste pipes.

15 Gaps around floor-to-wall joints (particularly with timber frame).

16 Gaps in and around electrical fittings in hollow walls.