First among equals

In the specification of building services products it is common practice for specified products to be replaced at the procurement stage by alternatives that are deemed as ‘equal and approved’. With many items of plant it is possible to carry out a relatively simple comparison between the specified product and the proposed alternatives to establish whether the performance is acceptable.

With lighting, however, there are many factors to be considered, ranging from energy performance and light distribution through electrical safety and maintenance requirements to aesthetic appearance. Assessing alternatives, therefore, is a complex procedure – and accepting an unsuitable alternative can have serious consequences for the performance of the lighting.

Specifiers who fail to carry out the proper procedures can also leave themselves open to legal proceedings from the end-user if the lighting does not perform as expected. Unfortunately, there has been little clarity as to what exactly constitutes ‘proper procedures’ and specifiers are often under pressure from other members of the project team to make decisions with which they are not comfortable.

Alternative action

The UK’s three leading lighting organisations – the Lighting Industry Federation, the Institution of Lighting Engineers and the Society of Light and Lighting – have joined together to produce guidelines for lighting specifiers when dealing with ‘equal and approved’ luminaires. Their proposals also have the support of the Electrical Contractors’ Association.

Paul Ruffles of Lighting Design & Technology, a member of the team that drew up the proposals, puts the issue into perspective: “As designers we often get frustrated after spending months poring over catalogues with clients and architects to agree just the right luminaire for key spaces – only to have a contractor come along and bounce the project manager into accepting a cheaper alternative. While these have the same wattage lamps in, they may not look the same or perform the same as the specified option,” he comments.

The proposals describe the key evaluative processes that must be applied to proposed alternative luminaires to ensure that ‘equal and approved’ means just that. Designers need to consider a wide range of issues including photometric equality, energy consumption, construction and robustness, aesthetic appearance, electrical equality and ease of maintenance (see ‘What exactly is an ‘equal and approved’ luminaire’, over).

Lighting designer Barrie Wilde has also been heavily involved in drawing up the proposals since the project began in August 2002. “The proposals are designed to provide a proper method of assessment that is understood by all parties,” he explains. “They are not designed to take away the manufacturers’ or contractors’ ability to negotiate, but it is the job of the designer to secure the best interests of the client. There has to be a clear audit trail to show that any alternative lighting has been thoroughly tested,” he continues.

The procurement process

Within the procurement phase of a project there is generally provision for contractors to offer ‘equal and approved’ or, perhaps more likely, to offer alternative luminaires via ‘value engineering’ exercises. These provisions are often encouraged by cost control and contract management consultants as the alternative luminaires usually offer a cost reduction. This cost advantage will nearly always be beneficial to the contractor (declared or otherwise), and may also have some financial benefit to the client.

There are other reasons for offering alternatives; such as delivery dates, manufacturing delays and trading closure; but in a properly managed and programmed contract these would be abnormal circumstances. Undoubtedly, cost advantage is usually the driver for offering alternatives.

It is important to note that there is no suggestion that all alternative luminaires are inferior to those specified originally. “In some areas I specify a luminaire from one manufacturer but could easily have chosen a similar product from two or three others,” notes Ruffles. “Here, if a contractor comes along with an alternative product that fulfils the specification in terms of appearance and performance, but is cheaper, then I am happy to accept this.

“The contractor is often better placed to test the market nearer to the time of supply than the designer, who may be selecting products six or nine months before they need to be ordered,” he adds.

There has to be a clear audit trail to show that any alternative lighting has been thoroughly tested

The process will be different for public bodies, who must comply with European procurement regulations.

Who is responsible?

The important factor is that the specifier responsible for the lighting design will generally have a responsibility for the effective and proper operation of the installed lighting systems – to deliver the intended lighting scheme both in aesthetic and technical senses. This includes compliance with the prescriptive quality and quantity parameters.

Failure to deliver a compliant lighting installation can result in litigation, so in many situations it will be incumbent upon the lighting designer to carry out rigorous interrogation of the alternative luminaires to ensure compliance with contracted obligations.

Here, there is the added problem that some obligations may have been set by other consultants, such as the electrical engineer, architect or interior designer. Failure to consult with these parties in the acceptance of any alternatives may put the specifier or lighting designer in a vulnerable position with these other parties, even though the lighting objectives may be scheme compliant.

With some building services equipment, another option is for the designer to write a performance specification then allow the contractor to select equipment that will provide that performance. Because of its highly visual nature, however, lighting specification is not generally that simple, as Wilde points out: “With lighting, the client and architect generally want to see the luminaires before installation, so you end up with a schedule of luminaires. A specification based just on performance provides no guidance on the aesthetics of the fittings.”

All of which means that actual responsibilities, explicit or implicit, have to be understood by individual specifiers and/or lighting designers. These will be the subject of terms and contract conditions, forms of contract, agreed scope of works and deliverables etc. What is clear is that once a specifier or lighting designer enters into the evaluation and approval process of alternative luminaires they take on board both legal obligations and a financial commitment that may not be reimbursable.

Contractors in charge?

An alternative approach is for the contractor to take on the responsibility for the performance of the proposed alternatives although, again, this may not be as simple as it sounds. “When an alternative luminaire is put forward by a contractor someone has to carry out checks that it conforms to the specified standards, that it does not affect the energy use calculations for Part L and that it provides the same task and room surface illuminance as the specified luminaire,” notes Ruffles.

“If the original designer is to carry out these checks and calculations then someone will need to pay them as it is unlikely to be covered by their original appointment by the client. Alternatively the contractor will need to carry them out, which means they then take on certain aspects of the design responsibility for the project, which can be problematic if things subsequently go wrong,” he adds.

Ideally, then, the lighting designer will be in a position to carry out a thorough evaluation of any proposed alternatives and will be paid for the extra work involved. In these circumstances, there is a number of criteria that need to be applied when engaging in such an exercise; these are described in the box below.