"I can hear (too much noise from) my neighbours, how can this be improved?" is one of the most common questions asked of acoustic consultants.
People are understandably sensitive to and intolerant of noise between dwellings.
Increased noise is partly a consequence of modern living e.
g.
powerful stereos, high density living, housing stock formed by the conversion of unsuitable buildings.
In addition failed building regulations compounded the issue and led in 2003 to compulsory sound testing with the introduction of Approved Document E to the Building Regulations.
Has compulsory sound insulation testing improved the sound insulation between dwellings? Yes, definitely, but the situation is not as black and white as it may initially seem.
To put the problem in context a brief historical overview can help.
In the late 60s, building regulations included sound insulation performance standards for the first time on a national basis - prior to this they were dealt with locally.
These regulations had varying, but similar, incarnations up until the introduction of Approved Document E in 2003.
Essentially the regulations pre-2003 specified a number of building designs and materials that if followed were assumed to provide satisfactory sound insulation in residential dwellings.
Dwellings built using this approach were declared as "deemed to satisfy" and issued with a completion certificate by the building control body as having complied with the sound insulation regulations.
This, almost self-certification scheme, was flawed and failed on a number of counts:

1. If a builder used an alternative design method, the sound insulation properties of the design would require testing.
   Providing the test results met the requirements this report could be used in any number of subsequent constructions even though the site conditions would be very different and the design not suitable.
   
2. Certain published designs offered inherently poor sound insulation performance!
3. The sound insulation properties of a construction depend largely on the quality of the workmanship.
   

A consultation paper prior to the 2003 regulations highlighted the failings of the "old" regulations with a massive 40 % of separating floors, and 25% of separating walls failing to achieve the performance standards required.
This led to the introduction of the 2003 regulations and compulsory sound insulation testing.
The 2003 Building Regulations do not apply retrospectively and therefore only new builds and conversions after this date are given this heightened level of regulation protection that hopefully offers the enhanced quality of life one would expect.
Problem solved? You would think so, but unfortunately the Building Regulations and Approved Document E arguably fall short of the mark.
Approved Document E recommends that only up to 10% of the rooms in a development require testing.
Typically this is fine for a small development, as it covers most living accommodation areas.
However, it can be a flaw in larger developments where the potential occupier has a 90% chance of occupying a dwelling that has not been tested and may fall short of the required levels of soundproofing.
The other potential shortcoming of the Approved Document E is the procedure if a test fails.
A failed test should raise questions regarding the party walls/floors in the development that have not been tested and the following process should take place:

1. An investigation into the reason for the failure.
   
2. Remedial work once the problem has been identified.
   
3. If the failure is attributed to the construction and/or the associated flanking elements, remedial work should be carried out on the walls/floors that have not been tested.
   
4. The developer should demonstrate to the satisfaction of the building control body that the other rooms meet the performance requirements.
   
5. After a failed set of tests, the rate of testing should increase until the building control body is satisfied that the problem has been solved.
   

In reality this increased level of tests rarely happens.
The single wall or floor that did not achieve the required sound level performance typically has the appropriate remedial measures, a re-test is commissioned and the appropriate certificates issued by the acoustic consultancy.
Building Control receives the certificate and signs the building off none the wiser that there may be a fundamental flaw with the soundproofing in the rest of the development.
To summarise, buying a property that was newly built or formed by the conversion of an existing dwelling prior to 2003 Building Regulations significantly increases your chances of being disturbed by your neighbours.
Developments completed since 2003 are much more likely to have far greater sound insulation, although, as this article has tried to highlight, not a guarantee.
As an acoustic consultant my advice would be to ask the "noisy neighbours" questions before you rent or buy the property, or even commission a sound insulation test prior to procedure.
Yes, it is an additional expense, but can you put a price on a good quality of home life?