Parking in towns and cities can be difficult, and expensive. This sentiment represents the experience of commuters who battle daily to find a suitable space for their vehicle. Having found a space, perhaps in a multi-storey car-park, commuters will give little thought to the question of the robustness of the design and construction of that structure. However, this question is one that has arisen in a number of cases that we have handled recently for clients.

It may simply be a coincidence that these cases have occurred independently of one another, yet more or less at the same time; or this may reflect common factors, such as price pressures meaning that car-park constructions which are part of wider leisure developments, for example, are seen as an opportunity to save money. From a legal perspective, the critical aspect when problems arise is whether or not the relevant contractual provisions deal adequately with the design and durability requirements and, ultimately, liability.

When things go wrong

 One of the most notable adversaries of the British developer, designer and constructor is inclement weather. It is critical that developments are designed and built to withstand the elements. This is particularly so for flat structural elements where precipitation is liable to gather or run across. The consequences of inadequate design in this context are illustrated by the following example. A multi storey car park was built to serve a leisure complex in the west of Scotland. It is windy and it rains a lot in the west of Scotland! The car park in question was built with open sides. As a result, whenever it rained, the wind drove the water into the car park. Drains were installed, but only at ground level.  This combination led to flooding within the raised floors of the car park. The water had nowhere to go and so remained until it evaporated. The car park was consequently not fully operational until the situation was remedied some time later.

Clearly design issues such as this should not arise. However, the position was aggravated through poor concrete finishing, which increased the pooling problem within the car park, and through a number of other instances of water ingress due to defective workmanship and materials. It is important that the works specification is tightly drafted so that pitfalls such as these are avoided, or at least so that when things do go wrong, it is possible to pin down the responsible party. This is not simply a case of blame-shifting. It is important that the various contract documents are drafted in such a way as to remove any doubt over who is responsible for design and construction defects respectively. That way, it will be clearer as to who is the responsible party so that the necessary rectification measures are more likely to be undertaken promptly, either with or without the intervention of an insurer.


The importance of durability cannot be understated.  Car parks are exposed to rougher treatment than conventional buildings, and problems caused by substandard concrete are more easily aggravated. We have seen this on more than one occasion recently.

The most common and severe cause of steel reinforcement corrosion in the UK is the presence of chlorides (salts and similar elements) within the concrete in which the steel is embedded. Such chlorides inevitably find their way through time into car park structures, whether through grit scattered across the parking surface or through being brought in and deposited by vehicles. Where the concrete is of inadequate strength, or where there are inadequate protections in place, the risk of corrosion is higher. This will through time cause cracking and spalling in the concrete which will in the longer term lead to further distress and further remedial costs.

Another common problem affecting car parks is freeze-thaw attack. This occurs where the water content of concrete freezes and expands, before thawing again. This process often repeats itself and ultimately leads to deterioration of the concrete. As with corrosion, the problem can be aggravated by the use of de-icing materials.

From the construction lawyer’s perspective, these issues can lead to disputes and our experience reflects this. The importance of pinpointing liability when things do go wrong is highlighted above. Separately, there is an obvious benefit in identifying defects as early as possible so as to minimise damage and the resulting remedial costs. This can be facilitated through effective provisions on testing at completion, in addition to requirements for on-going monitoring and interrogation of the materials being used during construction. Consideration may also be given to extending the defects liability period under the contract given that certain problems may well only manifest themselves after some time.


Whilst car parks should be sufficiently robust to withstand the elements and heavy trafficking for an adequate period of time, there is also a more subtle consideration to bear in mind. In recent decades, new cars have been steadily increasing in size. Whether this trend will continue in light of current efforts to introduce for more fuel efficient vehicles is open to question. Nevertheless, when considering the proposed height, length and width of spaces, one should consider the possibility that the trend towards larger vehicles will continue. Of course, this must be offset against the cost of providing fewer spaces.

When it comes to the actual construction of the car park, there are further considerations to bear in mind. For example, will the dimensions be taken to the midpoint of the white lines separating spaces? If not, the thickness of the white lines could be critical. In multi-storey constructions, will vertical columns falling within spaces be included as part of the space? This could have a significant impact. Is there to be a tolerance for deviations to the specified dimensions? The potential difficulties are readily apparent, and it is important to provide for these eventualities. These issues have materialised in the recent cases we have been involved in.


For the avoidance of doubt, our observations above simply reflect our experience in recent cases which we have been involved in; they do not constitute design advice! Also, it must be acknowledged that some problems arise unexpectedly. However, there are lessons to be learned from these experiences, not least that the design and specification of car-parks is of crucial importance. The car-park is not to be viewed simply as an incidental element of a leisure development; rather it has the potential to enhance the overall leisure experience and similarly to significantly undermine that experience where problems arise. The cost of remedying defects can be significant, and can escalate where the problems are not identified at an early stage. This highlights the need for on-going monitoring throughout construction, and adequate testing at completion.

The British Parking Association published detailed guidance on the design of new build car parks in 2010. This can be viewed by clicking on the link below.