Structural & Site Concrete

Bids received

due Oct 1, 2026

Negotiating room

$4M15% bid spread$4.6M

Bids with scope gaps

4 of 5 have gaps67% avg

Line-by-line floor

$4.3M

$280K below cheapest complete option

Next steps

Suggested moves from the analysis — to use as leverage, not a recommendation to award.

Summary

The cross-bid takeaway — overview, key findings, and recommendation.

Adjusted prices cluster tightly between $4.06M and $4.60M, but only Brindlewood at 95% scope coverage is a complete offer — the other four are cheaper only because they have stripped waterproofing, gypsum underlayment, polished concrete, ROW concrete, weather protection and the low-carbon mix requirement. Brindlewood's $4,603,500 is roughly $540K above the low bid, and the missing scope in that low bid is worth more than that gap once bought out.

Key findings

Adjusted totals: Ironvale $4,062,690, Maplestone $4,236,000, Kestrel Ridge $4,288,000, Tannerbrook $4,345,300, Brindlewood $4,603,500. The $541K spread between high and low is almost entirely explained by scope Brindlewood includes and the others exclude — $109,500 of waterproofing, $131,000 of gypsum underlayment, $62,600 of polished concrete, $93,800 of ROW concrete, $36,500 of weather protection and the low-carbon mix premium.
Kestrel Ridge at 47% scope coverage is not a usable offer: it substitutes prohibited dampproofing for the specified sheet membrane, assumes free use of a GC tower crane and hoist that will not exist, excludes all shoring engineering and survey, acknowledges neither addendum, and proposes 30 weeks against the required 26.
Tannerbrook's $4,345,300 adjusted (66% coverage) rests on an unacknowledged Addendum 2 with all post-Addendum-1 changes excluded, an $85,000 waterproofing allowance with no sub-tier quote, and rebar at 280 tons versus the 286-ton reference — three open items on a 100% CD set.
Ironvale's low number at 62% coverage carries two open-ended risks beyond its exclusions: rebar at 262 tons with overage billed at $2,150/ton (about $52,000 of exposure to reach 286 tons) and all cold-weather protection on time and material for a January Portland start.
Maplestone at $4,236,000 (63% coverage) walks away from three entire categories — right-of-way concrete, the sixteen metal pan stair flights and all winter protection — and layers on non-standard payment terms including 10% mobilization at NTP and 5% retainage.

Recommended to award

Award to Brindlewood Concrete Structures at $4,603,500 lump sum with no necessary alternates — it is the only bid at 95% scope coverage with both addenda acknowledged, a 24-week duration beating the 26-week requirement, named rebar, PT, waterproofing and shoring-engineering subs, and no high-severity risks. The $541K premium over Ironvale's $4,062,690 adjusted price is more than consumed by the waterproofing, gypsum underlayment, weather protection, joint sealant, low-carbon mix and 24-ton rebar exposure Ironvale leaves open; confirm Brindlewood's bid validity extension from 60 to 90 days and price Alternate 3 bonds at $46,035 if required before signing.

Bidders

Ranked by adjusted value (base + alternates to close scope gaps). Click a bidder for a coverage drill-down.

Line-item comparison

Grouped by CSI section — expand only what you need. Cheapest carried price per line glows teal.

Focus:

Scope section / line	Tannerbrook Structural Concrete $4.3M · 66%	Maplestone Concrete Constructors $4.2M · 63%	Brindlewood Concrete Structures $4.6M · 95%	Kestrel Ridge Concrete $4.3M · 47%	Ironvale Concrete and Formwork $4M · 62%

A. General requirements 01 10 00· 5 lines	$241,2001 gap	~$174,0002 gaps	$238,500	~$240,0004 gaps	$200,5002 gaps
B. Foundations 03 30 53· 3 lines	$803,900	$902,000	$808,300	$1,012,000	$771,650
C. Slabs on grade 03 31 00· 2 lines	$231,500	$233,500	$229,600	$241,000	$218,970
D. Vertical concrete 03 30 10· 2 lines	$611,100	$611,000	$626,200	$618,000	$590,100
E. Elevated decks 03 30 20· 3 lines	$1,213,000	$1,203,000	$1,226,600	~$1,238,000	$1,155,000
F. Reinforcing and post-tensioning 03 20 00· 2 lines	$687,500	$708,000	$717,900	~$722,000	$677,750
G. Below-grade waterproofing 07 13 26· 1 line	$85,000	$98,500	$109,500	—1 gap	—1 gap
H. Stairs, curbs and pads 03 30 30· 3 lines	$112,400	$98,5001 gap	$117,200	$119,0001 gap	$111,000
I. Finishes and toppings 03 35 00· 4 lines	$43,9002 gaps	$59,5002 gaps	$237,800	—4 gaps	$35,4403 gaps
J. Site concrete 32 13 13· 1 line	$97,300	—1 gap	$93,800	—1 gap	$90,340
K. Placing, hoisting and protection 03 30 40· 4 lines	$184,200	~$148,0001 gap	$198,100	~$98,0003 gaps	$150,1401 gap
Base bid total	$4,311,000 adj $4,345,300	$4,236,000	$4,603,500	$4,288,000	$4,000,890 adj $4,062,690

Cheapest on this lineExplicitly excludedNot addressed (silent gap)· "adj" = base + scope-gap alternates· "~" = estimated share of a bidder's lump sum, not a price they quoted for that line; never counted as cheapest

Alternates

The same alternate, bidder by bidder. Tick one to take it from every bidder who priced it.

Alternate	Tannerbrook Structural Concrete	Maplestone Concrete Constructors	Brindlewood Concrete Structures	Kestrel Ridge Concrete	Ironvale Concrete and Formwork
Alternate 1PT slab in lieu of mild-reinforced slab at Level 1	deduct $96,000	deduct $82,000	deduct $88,000	not listed	deduct $104,000
Alternate 2Crystalline admixture in lieu of sheet membrane at walls	deduct $28,000	not priced	deduct $36,500	not listed	not priced
Alternate 3Payment and performance bond	not priced	add $52,950	add $46,035	not listed	add $44,010
Alternate 4Accelerate to 22 weeks	add $71,500	not priced	add $64,000	not listed	add $58,500
Adjusted totalbase bid plus every alternate taken	$4,345,300	$4,236,000	$4,603,500	$4,288,000	$4,062,690