Comparing BMS tender returns: a guide for main contractors

When you receive three BMS quotes with three different point counts, how do you know which one is right? What to look for, what questions to ask, and how an independent scope baseline helps.

Why BMS quotes vary so much

It is not unusual to see BMS tender returns differ by 40% or more, even when all contractors are pricing the same specification. This is not because some contractors are twice as expensive as others. It is because BMS estimation involves hundreds of small interpretation decisions, and each one affects the final price.

The three sources of variation

Scope interpretation

The biggest source. Different estimators read the same specification and reach different conclusions about what is included. Does the VRF system need individual indoor unit monitoring, or just a gateway interface? Are the meters BMS-scope or provided by the metering contractor? Each of these decisions can swing the price by thousands of pounds.

Points methodology

Even when contractors agree on scope, they may count points differently. Some count pump duty and standby as separate items. Others count them as a set. Template point counts vary — one contractor's AHU template might have 25 points, another's might have 35.

Pricing rates

Hardware, labour and commissioning rates differ based on supply chain, overhead structure and margin targets. But this is usually the smallest source of variation.

What to look for when comparing

Ask each contractor for their points schedule, not just a lump sum. Compare the equipment lists side by side. Look for items that appear in one return but not another — these are scope interpretation differences. Compare total point counts by type (AI, DI, AO, DO, HL) to identify methodology differences.

How a scope baseline helps

If you have an independent equipment list and points schedule before you send the tender pack to subcontractors, you have a benchmark to compare their returns against. You can see which contractors have included items you expected and which have missed them. You can identify where their assumptions differ from yours.

This is what Tenderfly provides for M&E contractors and main contractors: an independent BMS scope baseline generated directly from the tender documents. Not a quote — a scope definition you can use to evaluate the quotes you receive.