Comparing MEP Supplier Quotations Fairly

Three quotations for the same item list rarely describe the same scope. Comparing the totals directly is how projects end up with variation orders later, and how a buyer who did nothing wrong gets asked six weeks afterwards why the cheap offer cost the most.

Normalise before you compare

Rebuild each quotation onto a common basis:

• Same quantities and units — watch for prices given per metre against per length
• Same material grade and pressure class
• Delivery included or excluded, stated consistently
• Same currency and the same validity period
• Same pack or bundle quantity, so a box price is not compared with a piece price
• The same revision of the item list, if the list was reissued during the tender

Build one comparison sheet

Do the work in a single sheet with one row per line item and one column per supplier, not by reading three PDFs side by side. Three habits make it reliable:

• Leave a cell blank when an item was not quoted. Never enter zero — a blank that becomes a zero is the classic route to an under-priced award.
• Keep an exclusions column per supplier and write the exclusion in the supplier's own words.
• Extend every line yourself from unit rate and quantity rather than trusting the totals. Arithmetic errors in quotations are ordinary, and finding one before award is a favour to both sides.

Where a supplier has quoted a different but acceptable product, keep the original line and add the alternative underneath it rather than overwriting. You will need both when the consultant asks what was compared.

Look for what is missing

An unusually low price often reflects a narrower scope. Check whether the quotation excludes accessories that the installation genuinely requires — gaskets, bolts, adaptors, supports, or commissioning items. A fitting priced without its jointing materials is not cheaper, only incomplete.

The same gap appears system by system. A plumbing package quoted without solvent cement, welding consumables or clamps; an electrical package without glands, lugs, earthing accessories or the enclosure the breakers are supposed to sit in; a fire fighting package quoted at equipment level with none of the hangers, escutcheons and adaptors that actually get it installed. Price the system, not the headline items.

Check technical compliance line by line

Confirm each substituted item is genuinely equivalent, not merely similar. Pay attention to pressure rating, temperature range, material grade and any approval named in the specification.

Some substitutions are equivalent on the datasheet and not on site:

• A stainless steel fitting offered in a lower grade than specified, in a coastal or wash-down location
• A flange at the same nominal size but a different drilling standard, which will not bolt to what is already installed
• A breaker at the correct current rating but a lower breaking capacity than the board requires
• A pump that meets the model reference but sits away from the actual duty point on its curve
• Air conditioning capacity quoted at a moderate ambient condition where the specification asked for high-ambient rated performance

Any one of these can pass a total-price comparison and fail a submittal review.

Weigh lead time as a cost

Material that arrives four weeks late can idle a crew or delay a handover. When one supplier is cheaper but significantly slower, express the delay in real programme terms before deciding.

Ask what the delay actually blocks. An item that holds a concrete pour, a ceiling closure or an inspection is worth more than its line value; a spare or an accessory fitted at the end is worth roughly what it costs. Ask also whether partial release is possible, because a supplier who can send the first-fix items while the rest follows may solve the programme problem outright.

Score the commercial terms, not only the number

Validity period, payment terms, price basis, part-shipment and who carries the cost of re-work if a submittal is rejected are all part of the comparison. Two offers with identical bottom lines can carry quite different exposure. Write these into the sheet as columns so they are visible at the moment of decision rather than discovered in the purchase order.

Be careful with split awards

Splitting a package across suppliers on line-by-line lowest price looks efficient and often is not. It multiplies delivery events, and it puts the interfaces — thread standards, flange drilling, coupling systems, connection types — on your side of the table. If you do split, split along system boundaries rather than through the middle of one.

Assess the supplier, not only the offer

Availability of stock, willingness to quote alternatives, response speed to a technical query, and clarity of documentation all affect how the supply performs once the order is placed.

The cheapest useful test costs nothing: send one real technical question during the tender and see what comes back. A supplier who answers precisely, in writing, before they have the order is telling you something about how the next six months will go.

Award on total delivered value

The decision should reflect compliant scope, realistic delivery, complete accessories and the commercial terms together — not the headline figure alone. Write a short award note recording what was normalised, what was excluded and why the chosen offer won. It takes ten minutes and it is the document that settles the argument later.