Compared with the traditional list, the simulation list has a re-measurement link, which seems simple, but in fact it is full of traps and will be seen through if you are not careful. Because the tenderer is not only the maker of the rules of the game, he is both an athlete and a referee, and he has the supreme right to speak.
Because bidders have a habitual thinking mode about traditional calculation rules, it is difficult to prevent them, which puts forward higher requirements for the comprehensive ability of bidding business personnel.
Trap 1: fuzzy rule
The calculation rules of remeasurement of many tender documents adopt the quota rules (non-quota rules) of the tenderer's enterprise, and its calculation rules are characterized by incomplete rules, unclear premises and various interpretations, so as to achieve accuracy by fuzziness. Once there is a dispute, it is similar to "the final interpretation right of this activity belongs to the organizer", and your rights and interests are damaged.
Example 1, calculation rule: floor heating is calculated according to ground area.
During the review of retest, the owner does not calculate the net area of the floor, but calculates the area according to the skin size of the outermost pipe of the floor heating coil, deducting the engineering quantity between the wall and the first pipe (see figure 1). Reason: The distance from the wall to the first pipe is outside the area of floor heating. The area occupied by toilets should also be deducted. Reason: There is no floor heating pipe in the bathroom. As for why the floor heating area should be deducted, it is ignored.
What is the floor area of floor heating? Your habitual thinking must be the net area in the set. Rules use your mentality to achieve accuracy through vagueness. Because of the non-quota rules, the quota station can't explain it, so it can only be negotiated by both parties, and the right of interpretation ultimately lies with the owner. Originally, there was a low-profit unit price, but this deduction was lost in an instant due to the reduction of engineering quantity. Taking the 4.90× 3.60m master bedroom as an example, the actual amount of work deducted is: (4.70×2+3.24×2-0.90 room door) ×0. 16 spacing ≈ 2.40m? , accounting for 2.40(4.7×3.4)≈ 15.0% of the ground area. 1.6 million m? After deducting ≈ 15% of the engineering quantity, the loss is not huge.
Example 2: Calculation rule: The railing shall be calculated in linear meters according to the size shown in the figure.
One or both sides of the stainless steel railing of the balcony are external walls, and the external walls are FS integrated insulation boards with a thickness of 100 mm ... The fact that embedded parts or expansion bolts are anchored in the structure is completely ignored during the audit, and the length of insulation board thickness is forcibly deducted (see Figure 2). Reason: as shown in the figure. Concave balcony on both sides against the wall, a total of 200mm, the outer railing is made of 304 stainless steel. The unit price of 240 yuan per meter, after deducting the 48 yuan of a balcony, is 1.6 million m? Housing projects add up to a very large amount.
Trap 2: Double standard weight
Calculation rules: doors, windows, holes, hollow rings and ... embedded in the wall are deducted from the masonry project, and the volume of tiger-headed bricks on the windowsill protruding from the brick wall ... the overhangs and waistlines below the three-skin bricks are not increased.
There is almost no difference between the bidding calculation rules and the quota calculation rules. Because the rules are not clear about the size shown in the drawings or the construction size, the hole will be deducted according to the width of 0.9× 2.3 1 instead of the size of 0.9×2.20 in the floor plan and the door and window table (see screenshot 3). Reason: There is no brick wall under the door. Because there is no masonry, it is necessary to deduct the thickness of the floor heating layer and the surface layer according to the construction size (see Figure 4).
However, when calculating the plastering area of external wall insulation, the hole area is still deducted from the drawing size, not the actual construction size (see Figure 5).
For example, the specification of the external window is 1800× 1400, and the actual construction size of the window wall with 30mm thick thermal insulation mortar is ≈ 1740× 1340. Although the construction method of each unit is different, the size of the hole will be different after survival, but it must be less than 1800× 1400.
Trap 3: the enemy is clear and I am dark, and the word game.
Example 1. Calculation rule: Concrete shall be executed according to C30 average unit price, regardless of label.
When the owner invited bids, only a few building plans were issued, and there were no structural drawings and no structural descriptions. Bidders can't judge at all, and they can't judge at all. After repeated survey, the weighted average unit price of engineering concrete exceeds C35. According to the local market, the price difference of a grade of concrete is 15 yuan. The specific content of the project is 0.49m3/m? . This alone, the loss is equivalent to the construction area of 7.35 yuan /m? .
Obviously, people who know the design intent only dare to make such rules if they entrust the design tenderer. Obviously, they came prepared, but the enemy was clear and I was dark. If you are not completely sure, you will not make such rules and you will not take the risk.
Example 2: Calculation rules: The information price of "C30 commercial concrete is not pumped" in "×× Market Information" shall prevail, and the pumping fee shall be calculated separately.
This law has wonderful logic and malicious definition: non-pumped concrete+pumped concrete = pumped concrete.
The slump of pumped concrete is large, and the dosage of cement and pumping agent is large, so the unit price is slightly larger than that of non-pumped concrete. The information spread between local pumped and non-pumped concrete is about 10 yuan /m3. Playing with words, the bidding documents are preceded by a word "not". This seemingly random word "no" is equivalent to the construction area of 4.5 yuan /m? (The pumping concrete volume is about 0.45m3/m? )。
Trap 4: the supreme right to speak, unilateral coercion
Tender documents: material adjustment: this general contracting tender adjustment only adjusts the prices of five main materials: concrete, steel bar, masonry, wire and cable and steel pipe (welded steel pipe, galvanized steel pipe and seamless steel pipe). ...
As we all know, masonry is a combination of brick and mortar, and mortar is a part of masonry, so the cement, yellow sand, lime and even water that make up mortar should also be adjusted. However, when adjusting the price, the owner only makes up the difference between bricks and blocks, and cement, yellow sand and lime are not adjusted. Reason: Cement, yellow sand and lime are not masonry. And confidently, there is no doubt: our company has always been a policy. Cement, yellow sand and lime are not adjusted in all development projects all over the country, and this project is no exception.
In fact, the owners also know that this is caused by the lack of definition in words and imprecise logic. For example, cement, yellow sand and lime in masonry mortar should be adjusted. As soon as this opening is opened, the bidders of cement, yellow sand and lime used for plastering mortar are bound to adjust. A project can't do one country, two systems, only adjust the masonry mortar. Therefore, we can only forcibly deny it, so as to avoid endless future troubles.
Similarly, under the premise that the definitions of engineering materials and turnover materials are not clear, the adjustment of amortized steel pipes (both welded steel pipes) in formwork support and scaffolding is also forcibly cancelled.
Example 2: When calculating the thermal insulation plastering of the side wall of doors and windows, only the plastering of the concrete surface of the side wall is calculated, and the plastering area on the FS thermal insulation board with a thickness of 100mm is not calculated. (see chart 6)
Taking the window of 1.8× 1.4 as an example, the amount of work deducted is (1.8+1.4) × 2× 0.12 (100 mmfs insulation board+20. 30% of the window area. Adding polymer anti-crack mortar, grid cloth, external coating, continuous work and materials, the actual cost is 120 yuan /m? Above. According to the estimate that the area of external doors and windows accounts for 0.28 of the construction area, it is 1.6 million m? The cumulative loss of residential projects (considering the relatively small proportion of the side wall area of the door) is about one million, which is not huge.
conclusion
The above example is just a drop in the ocean, and there are countless rules and clauses that exclude the tenderer's own obligations and the rights and interests of bidders by format clauses. According to the data analysis after recalculation, the cost affected by the above unfair rules accounts for more than 1.5% of the total price. Among them, if the bidder has strong comprehensive technical ability, some of them can be effectively prevented, but those bullying and unilateral coercion are irreparable. Most of the traditional lists are "famous guns", while in the simulation list, besides "bright guns", more are "dark arrows". Therefore, the impact of bullying and unilateral unfairness on the cost should be considered when quoting.
The most important and most difficult point of the simulation list is the cost prediction and estimation (based on the estimated total price of the simulation list, the investment and settlement amount of the project are comprehensively calculated). Especially if there are no drawings in the simulation list or only a few scheme drawings are provided, such projects should be described in the simulation list, and compared with the technical and economic index data in the database according to their own reality, local habits and market conditions. We should not only look at it from a micro perspective, but also judge it from a macro perspective. Micro factors should be considered as comprehensively as possible, and macro factors should be comprehensively evaluated and controlled (such as bullying and unilateral unfair factors mentioned above). Because, in many cases, in order to avoid risks, the reply given by Party A is: Please consider it yourself.
Tian Wei, a teacher in the cost circle, once said: "Emphasize the importance of the construction unit to calculate the bidding bill of quantities in the bidding stage, otherwise it may face heavy losses." "Being able to see the pit at a glance and stop the loss in time is the embodiment of the core competitiveness of the cost manufacturer." "Check the bidding quantity in the bidding stage" and "See the pit at a glance" are not just empty slogans, but the embodiment of experience accumulation and comprehensive strength.
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