Part L costs: Effecting efficiency

The revised Part L of the Building Regulations, which has been split into two documents, applies to all works started on site from 1 April 2002. It has far-reaching implications for specifiers, particularly in the design and installation of engineering services and the external building envelope.

The new regulations are designed to make the construction process more energy efficient in order to reduce carbon dioxide emissions from buildings, which in 2001 accounted for 46% of the UK's total emissions. The overall intention is to reduce emissions by 20% by 2010, or 1.3 million tonnes a year, in accordance with the Kyoto Agreement.

Apart from the obvious additional capital cost of labour and materials, the new regulations are likely to produce additional costs in the following areas:

• Design will take longer and be more detailed
  
• The programme will have to incorporate additional activities
  
• Testing of materials and techniques, plus mock-ups
  
• Pressure testing costs up to £50,000 for a large project
  
• Site inspections will be more frequent and recorded
  
• Capital allowances will possibly be reduced due to lower expenditure.

Although the overall impact of Part L2 (non-dwellings) is likely to add 5-10% to the costs of most construction projects, this will vary widely, depending on how the project team addresses the challenge.

It is not only important to focus on particular elements, but also to consider the project as a whole, recognising the impact of one element on another. The charts show the potential impact of Part L on typical projects.

Implications of Part L on project programme
Although it should be possible to eliminate most of the potential impact on programmes, the regulations have the potential to add time in the following areas:

• Briefing and concept design
  
• Detailed design
  
• Whole building design solutions
  
• Material selection
  
• Construction details
  
• Testing and commissioning
  
• Handover procedures
  
• Completion certificates
  
• Pressure testing
  
• Site inspection
  
• Remedy of defects
  
• Disputes (on quality, materials, completion, and so on).

Procurement and legal implications of Part L
There are a number of potential legal or contractual issues that need to be considered in relation to the regulations. They can be summarised as follows:

• Design responsibility
  
• Tender periods
  
• Handover responsibility
  
• Delay of completion certificates.

Where are the risks?
The regulations inevitably create new risks to everyone involved in construction, especially where they bring a need to change traditional forms of building. The costs and length of projects could be influenced either way, depending on how the inherent risks in the regulations are addressed. Part L does not have to cost more. In fact, on most projects the opportunity exists to mitigate or even reduce costs. The following can influence the way Part L is catered for:

• If a client has an inflexible brief or approach, it could restrict innovative solutions that help the building to comply with Part L inexpensively.
  
• The design team may need to be given more time to come up with the calculations and design solutions necessary to comply with Part L.
  
• Contractors and subcontractors must have enough time, and the appropriate skills and supervision, if they are to build to the required standards.
  
• There is a risk of compliance failure if manufacturers and suppliers fail to test their materials properly. Failure of products may lead to a delay in the issuing of completion certificates by Building Control. If the failure is catastrophic, the contractor may have to bear the cost of demolishing the building to remedy defects.

Minimising the impact of Part L
There are a number of strategic actions that a client, designer, contractor, supplier or operator can take to minimise the transitional risk of the regulations:

• Develop the design before tender
  
• Integrate the design team
  
• Appoint an engineering designer early in the process
  
• Minimise plant and equipment capacities
  
• Ensure buildability by getting input from the supply chain
  
• Draw up a realistic programme including adequate design, testing and correction
  
• Identify testing specialists in good time, such as pressure testing
  
• Test materials and techniques for quality, such as joints
  
• Conduct progressive site inspections, especially for covered items
  
• Ensure quality of trade-to-trade detailing, such as services penetrations
  
• Reflect all changes in the HVAC design brief, such as lower lighting heat loads.