FAR 52.249-10—Default (Fixed-Price Construction).
Plain-English Summary
FAR 52.249-10 is the default clause for fixed-price construction contracts. It tells the Government when it may terminate a contractor’s right to proceed for failure to prosecute the work diligently or failure to complete on time, and it explains the Government’s remedies after default, including takeover of the work, completion by another contractor or by other means, and use of materials, appliances, and plant at the site. It also addresses the contractor’s and sureties’ liability for damages, including excess completion costs, and sets out the contractor’s excusable-delay defenses for unforeseeable causes beyond its control and without its fault or negligence. The clause requires prompt written notice of delay, gives the contracting officer authority to investigate the facts and extend the completion time when warranted, and makes those findings final and conclusive subject to the Disputes clause. It further explains that if a termination for default is later found improper or the delay is excusable, the matter is treated as a termination for convenience. Finally, the clause states that the Government’s rights and remedies are cumulative, not exclusive, and includes special alternate provisions for demolition/dismantling/removal contracts and for contracts awarded during a national emergency.
Key Rules
Default for lack of diligence
If the contractor refuses or fails to prosecute the work, or any separable part, with the diligence needed to finish on time, the Government may terminate the right to proceed by written notice. The same remedy applies if the contractor simply fails to complete the work within the required time, including any approved extension.
Government takeover rights
After termination for default, the Government may take over and complete the work by contract or otherwise. It may also take possession of and use materials, appliances, and plant at the site that are necessary to finish the job.
Damages and excess costs
The contractor and its sureties are liable for damages caused by the failure to complete on time, whether or not the Government terminates the contract. This includes the Government’s increased costs to complete the work.
Excusable delay defense
The contractor is protected from default and damages if the delay is caused by unforeseeable events beyond its control and without its fault or negligence. The clause lists examples such as acts of God, government acts, acts of other contractors, fires, floods, epidemics, quarantine restrictions, strikes, freight embargoes, unusually severe weather, and qualifying subcontractor or supplier delays.
Prompt written notice required
To rely on excusable delay, the contractor must notify the contracting officer in writing within 10 days after the delay begins, unless the contracting officer extends that period. Failure to give timely notice can jeopardize the contractor’s ability to obtain relief.
Contracting officer fact-finding
The contracting officer must determine the facts and the extent of the delay. If the facts justify it, the contracting officer must extend the completion time. Those findings are final and conclusive on the parties, but they remain subject to appeal under the Disputes clause.
Improper default becomes convenience
If a termination for default is later found to be improper, or if the delay is determined to be excusable, the parties’ rights and obligations are treated as though the Government had terminated the contract for convenience.
Cumulative remedies
The Government’s rights and remedies under this clause are in addition to any other rights and remedies available by law or under the contract. The clause does not limit other legal or contractual remedies.
Special demolition alternate
For dismantling, demolition, or removal contracts, Alternate I changes the default remedy and adds a title-revesting rule if title to property is vested in the contractor. It also preserves the Government’s damage recovery rights.
National emergency alternate
Alternate II and Alternate III modify the excusable-delay language for contracts awarded during a national emergency. The key change is that the delay standard may exclude normal weather and focus on causes other than normal weather beyond the contractor’s control.
Responsibilities
Contractor
Prosecute the work diligently, complete the work within the contract time, and manage subcontractors and suppliers so delays do not become avoidable. Give written notice to the contracting officer within 10 days of the start of any delay that may be excusable, and support the request for time extension with facts.
Sureties
Remain liable with the contractor for damages resulting from default, including the Government’s increased completion costs, to the extent applicable under the bond and contract terms.
Contracting Officer
Monitor performance, determine whether the contractor has failed to prosecute or complete the work, issue written notice if termination for default is warranted, investigate delay claims, decide whether the delay is excusable, and extend the completion time when the facts justify it.
Government
If default occurs, it may take over and complete the work by contract or otherwise and may use necessary site materials, appliances, and plant. It must also treat a wrongful default or excusable delay as a convenience termination if later determined appropriate.
Subcontractors and Suppliers
Perform in a way that supports timely completion; their delays may be excusable only when they arise from unforeseeable causes beyond the control and without the fault or negligence of both the contractor and the lower-tier party.
Practical Implications
This clause is a major schedule-enforcement tool: contractors should track critical path progress closely and document any delay immediately, because late notice can undermine an excusable-delay claim.
Contracting officers should build a clear record before issuing a default notice, including schedule status, delay causes, and any prior warnings, because an improper default can convert into a convenience termination and create cost exposure.
The clause makes subcontractor and supplier delays the contractor’s problem unless the underlying cause is itself unforeseeable and beyond control, so prime contractors need strong flowdown management and procurement oversight.
For demolition and removal contracts, title issues can change quickly after default, so parties should pay close attention to property ownership, site removal, and disposition of materials.
The Government’s remedy is not limited to termination; it can also recover excess completion costs and other damages, so both sides should treat performance problems as potential financial exposure, not just schedule slippage.
Official Regulatory Text
As prescribed in 49.504 (c)(1) , insert the following clause: Default (Fixed-Price Construction) (Apr 1984) (a) If the Contractor refuses or fails to prosecute the work or any separable part, with the diligence that will insure its completion within the time specified in this contract including any extension, or fails to complete the work within this time, the Government may, by written notice to the Contractor, terminate the right to proceed with the work (or the separable part of the work) that has been delayed. In this event, the Government may take over the work and complete it by contract or otherwise, and may take possession of and use any materials, appliances, and plant on the work site necessary for completing the work. The Contractor and its sureties shall be liable for any damage to the Government resulting from the Contractor’s refusal or failure to complete the work within the specified time, whether or not the Contractor’s right to proceed with the work is terminated. This liability includes any increased costs incurred by the Government in completing the- work. (b) The Contractor’s right to proceed shall not be terminated nor the Contractor charged with damages under this clause, if- (1) The delay in completing the work arises from unforeseeable causes beyond the control and without the fault or negligence of the Contractor. Examples of such causes include- (i) Acts of God or of the public enemy, (ii) Acts of the Government in either its sovereign or contractual capacity, (iii) Acts of another Contractor in the performance of a contract with the Government, (iv) Fires, (v) Floods, (vi) Epidemics, (vii) Quarantine restrictions, (viii) Strikes, (ix) Freight embargoes, (x) Unusually severe weather, or (xi) Delays of subcontractors or suppliers at any tier arising from unforeseeable causes beyond the control and without the fault or negligence of both the Contractor and the subcontractors or suppliers; and (2) The Contractor, within 10 days from the beginning of any delay (unless extended by the Contracting Officer), notifies the Contracting Officer in writing of the causes of delay. The Contracting Officer shall ascertain the facts and the extent of delay. If, in the judgment of the Contracting Officer, the findings of fact warrant such action, the time for completing the work shall be extended. The findings of the Contracting Officer shall be final and conclusive on the parties, but subject to appeal under the Disputes clause. (c) If, after termination of the Contractor’s right to proceed, it is determined that the Contractor was not in default, or that the delay was excusable, the rights and obligations of the parties will be the same as if the termination had been issued for the convenience of the Government. (d) The rights and remedies of the Government in this clause are in addition to any other rights and remedies provided by law or under this contract. (End of clause) Alternate I (Apr 1984) . If the contract is for dismantling, demolition, or removal of improvements, substitute the following paragraph (a) for paragraph (a) of the basic clause: (a)(1) If the Contractor refuses or fails to prosecute the work, or any separable part, with the diligence that will insure its completion within the time specified in this contract, including any extension, or fails to complete the work within this time, the Government may, by written notice to the Contractor, terminate the right to proceed with the work or the part of the work that has been delayed. In this event, the Government may take over the work and complete it by contract or otherwise, and may take possession of and use any materials, appliances, and plant on the work site necessary for completing the work. (2) If title to property is vested in the Contractor under this contract, it shall revest in the Government regardless of any other clause of this contract, except for property that the Contractor has disposed of by bona fide sale or removed from the site. (3) The Contractor and its sureties shall be liable for any damage to the Government resulting from the Contractor’s refusal or failure to complete the work within the specified time, whether or not the Contractor’s right to proceed with the work is terminated. This liability includes any increased costs incurred by the Government in completing the work. Alternate II (Apr 1984) . If the contract is to be awarded during a period of national emergency, paragraph (b)(1) below may be substituted for paragraph (b)(1) of the basic clause: (1) The delay in completing the work arises from causes other than normal weather beyond the control and without the fault or negligence of the Contractor. Examples of such causes include- (i) Acts of God or of the public enemy, (ii) Acts of the Government in either its sovereign or contractual capacity, (iii) Acts of another Contractor in the performance of a contract with the Government, (iv) Fires, (v) Floods, (vi) Epidemics, (vii) Quarantine restrictions, (viii) Strikes, (ix) Freight embargoes, (x) Unusually severe weather, or (xi) Delays of subcontractors or suppliers at any tier arising from causes other than normal weather beyond the control and without the fault or negligence of both the Contractor and the subcontractors or suppliers; and Alternate III (Apr 1984) . If the contract is for dismantling, demolition, or removal of improvements and is to be awarded during a period of national emergency, substitute the following paragraph (a) for paragraph (a) of the basic clause. The following paragraph (b)(1) may be substituted for paragraph (b)(1) of the basic clause: (a)(1) If the Contractor refuses or fails to prosecute the work, or any separable part, with the diligence that will insure its completion within the time specified in this contract, including any extension, or fails to complete the work within this time, the Government may, by written notice to the Contractor, terminate the right to proceed with the work or the part of the work that has been delayed. In this event, the Government may take over the work and complete it by contract or otherwise, and may take possession of and use any materials, appliances, and plant on the work site necessary for completing the work. (2) If title to property is vested in the Contractor under this contract, it shall revest in the Government regardless of any other clause of this contract, except for property that the Contractor has disposed of by bona fide sale or removed from the site. (3) The Contractor and its sureties shall be liable for any damage to the Government resulting from the Contractor’s refusal or failure to complete the work within the specified time, whether or not the Contractor’s right to proceed with the work is terminated. This liability includes any increased costs incurred by the Government in completing the work. (b) The Contractor’s right to proceed shall not be terminated nor the Contractor charged with damages under this clause, if- (1) The delay in completing the work arises from causes other than normal weather beyond the control and without the fault or negligence of the Contractor. Examples of such causes include- (i) Acts of God or of the public enemy, (ii) Acts of the Government in either its sovereign or contractual capacity, (iii) Acts of another Contractor in the performance of a contract with the Government, (iv) Fires, (v) Floods, (vi) Epidemics, (vii) Quarantine restrictions, (viii) Strikes, (ix) Freight embargoes, (x) Unusually severe weather, or (xi) Delays of subcontractors or suppliers at any tier arising from causes other than normal weather beyond the control and without the fault or negligence of both the Contractor and the subcontractors or suppliers; and