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The Daily Insight

What is the difference between lump sum and GMP

Author

Olivia House

Published Apr 22, 2026

Unlike a lump sum contract wherein a contractor is paid a flat fee for the work, the guaranteed maximum price contract allows the owner to potentially save money if the project ends up costing less than estimated. … The total cost to the owner may be less than the guaranteed maximum price, but it will not exceed it.

What is a GMP allowance?

Allowances are typically used to cover the scope of items where the extent of the work is not known at the time the guaranteed maximum price (GMP) is submitted. … These variances in quantities and types, and therefore price, are typically reconciled with the allowance.

What is the difference between GMP and Cost-Plus?

That is why cost-plus pricing is often combined with a guaranteed maximum price (GMP). Cost-plus with GMP provides an upper limit on total construction costs and fees for which an owner is responsible. If the party providing the work under this pricing method runs over GMP, it is responsible for such overruns.

What does a GMP contract mean?

A guaranteed maximum price contract is a hybrid of a cost reimbursable contract and a fixed lump sum. A contractor is reimbursed the costs that it actually incurs when they are incurred, which assists with cashflow. However, unlike an alliance, those costs are capped at the Guaranteed Maximum Price or the GMP.

Is GMP a fixed price contract?

Cost-Plus GMP Contract Agreements are “cost reimbursement” contracts. In a Cost-Plus price arrangement, there is no set or Fixed Fee. In other words, the contractor is paid for the Cost of the Work it incurs to complete the project, plus a Fee, not-to-exceed the GMP (absent scope changes or extenuating circumstances).

How do you calculate GMP?

  1. the total number of years in working life (from 6 April 1978 or 6 April following 16th birthday if later)
  2. multiplied by 20%
  3. divided by 52.

Does GMP include contingency?

Because the construction contingency is included in the GMP amount, 100% of the contingency is ‘at risk’, and in the best case scenarios, the owner/developer will only recover a portion of the contingency.

What is the meaning of lump sum contract?

A lump sum contract or “fixed fee contract” is a traditional means of procurement in which a single “lump sum” price for all of the works is agreed upon before the works starts. … This means that the contractor is able to accurately price the risk they are being asked to accept.

How does a GMP project work?

A GMP, or a Guaranteed Maximum Price, is one of the most common pricing structures used by construction contractors. Under a GMP contract, the contractor is compensated for actual costs incurred, plus a fixed fee which covers risk.

Can a lump sum contract be audited?

Financial records for lump-sum contracts are usually not subject to an audit because the owner has agreed to pay one fixed price regardless of whether the documentation backs it up.

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What are some possible disadvantages of Guaranteed Maximum Price?

Disadvantages to the contractor : He may miscalculate the costs and may have to bear losses in the event of cost overruns. Due to the possibility of losses, the contractor may quote the higher price for the job and may lose the contract in competitive bidding.

What are the disadvantages of lump sum contracts?

  • Lump sum contracts pose greater risk to contractor.
  • Quantifying changes is a big challenge. …
  • Rejection of change order requested by the employer.
  • The building and construction design and plans have to be completed well before beginning the execution of activities.

What is the primary advantage of a negotiated GMP contract process?

This provides the following two advantages: (1) the Guaranteed Maximum Price offers the same protection as does the lump sum contract – it limits the owner’s risk and (2) unlike the lump sum contract, the owner has an opportunity to share in cost savings.

What is a GMP proposal?

A GMP proposal is a statement by a contractor manager of Guaranteed Maximum Price. It is added as an “Amendment and Agreement” after all the details of the construction are discussed with the construction manager, the architect/engineer team and the hiring company.

Is GMP paid in addition to State Pension?

GMP RECONCILIATION Members of the scheme paid lower national insurance contributions. They are not entitled to benefits from SERPS/state second pension for that period of service, although they are entitled to the basic state pension.

Does GMP affect State Pension?

If you have a Guaranteed Minimum Pension ( GMP ) the new State Pension could affect the amount of money you get when your reach your State Pension age.

At what age is GMP paid?

GMP payment age is 60 for females and 65 for males, which may differ from the normal retirement age of the scheme or indeed the age at which a member chooses to take their benefit (i.e. early or late). GMP accrues at different rates for males and females.

Why is lump sum contract good?

The advantages of a lump sum contract include: Lump sum contracts can be seen to reduce client risk as the price is fixed (although in reality it is still likely to vary, but not by as much as some other forms of contracting). It is widely accepted and understood as a method of contracting.

Does lump sum mean fixed price?

Under a lump sum contract, also known as a stipulated sum contract, the project owner provides explicit specifications for the work, and the contractor provides a fixed price for the project. … Despite the “lump-sum” moniker, this term refers to how the project is priced rather than the payment terms.

Who is at risk in a lump sum contract?

Contractors will carry much of the risk with a lump sum contract. With the exception of owner-initiated changes, if there are any cost overruns outside of the agreed fixed price, the contractor is responsible for those costs.

What does GMP mean in construction?

Lump sum — or fixed price — and cost-based contracts are the two main players in this arena, the latter of which is the basis for the cost-plus-fee with a guaranteed maximum price contract, or GMP.

What are the 3 types of contracts?

  • Fixed-price contracts.
  • Cost-plus contracts.
  • Time and materials contracts.

What are the advantages and disadvantages of lump sum contract?

A lump sum agreement presents a higher risk to a contractor. Measuring the number of changes is difficult. Such contracts require paperwork and records of change orders from each phase, and this means further documentation is needed. A rejection of change order can be asked for by the employer.

Does lump sum contract include taxes?

Lump sum contract When a construction contractor fabricates or processes materials prior to installation and is not acting as a seller of the materials, no tax is due on the processing costs; only the contractor’s actual material cost is subject to the tax.

When would you use a lump sum?

When to Use This Type of Contract A lump-sum contract is a great contract agreement to be used if the requested work is well-defined and construction drawings are completed. The lump-sum agreement will reduce owner risk, and the contractor has greater control over profit expectations.

Is fixed price contract same as lump sum contract?

A stipulated sum contract, also called a lump sum or fixed price contract, is the most basic form of agreement between a contractor and owner. This contract should be used if the scope and schedule of the project are appropriately defined to allow the contractor to fully estimate project costs.

How does lump sum differ from a unit price cost?

A lump sum bid represents the total price for which a contractor offers to complete a facility according to the detailed plans and specifications. Unit price bidding is used in projects for which the quantity of materials or the amount of labor involved in some key tasks is particularly uncertain.