Can an addendum change the main contract?

Yes. A correctly executed addendum modifies the original agreement to the extent specified. Ensure the addendum references the original contract by title and date and is signed by authorized parties.

Is an electronic signature valid here?

Yes in most cases. Electronic signatures are enforceable under the ESIGN Act (15 U.S.C. ch. 96) and UETA where adopted; exceptions (wills, certain court filings) do not generally apply to construction addenda.

Who must sign the addendum?

Authorized signatories for each party must sign. Verify signature authority against the main contract or corporate authorization documents before execution to avoid later disputes.

Do I need a notary or witness?

Not typically required for ordinary contract amendments, but state or project-specific rules may require notarization for certain instruments or owner policies; check state or contract provisions.

What if a party refuses to sign?

Absent mutual agreement, unilateral changes are unenforceable. Document attempts to negotiate and consider alternatives such as change orders under existing change-management procedures.

How do I correct an executed addendum?

Create a new addendum that states it supersedes the prior one, or execute a mutual amendment that corrects the error and is signed by all original signatories.

Electronic Signature
Templates
Project Management
Project Management Construction Addendum

Project Management Construction Addendum

This template is fully customizable. Edit the text, fill out the fields, and send it for signature. Give it a try!

PROJECT MANAGEMENT CONSTRUCTION ADDENDUM

Project Identification

Project Title Project ID / Contract No. Client Name Client Address (for notices) Service Provider (Party performing construction management) Project Manager (PM)

Recitals and Purpose

This Construction Addendum (the "Addendum") amends and supplements the existing Project Agreement dated with Contract No. . The parties agree that the terms of the Project Agreement remain in full force except as expressly modified herein. The purpose of this Addendum is to define additional construction management services, schedule adjustments, budget modifications, and acceptance criteria specific to the construction phase described below.

Scope of Work

Detailed Scope Out-of-Scope Items

Deliverables and Acceptance Criteria

The Service Provider will furnish the following deliverables and each deliverable will be subject to the acceptance criteria set forth below. Acceptance shall be confirmed in writing by the Client within the timeframes provided.

Deliverable 1 - Description Deliverable 1 - Acceptance Criteria Deliverable 2 - Description Deliverable 2 - Acceptance Criteria Deliverable 3 - Description Deliverable 3 - Acceptance Criteria

Timeline and Milestones

Commencement Date: Completion Date:

Milestone 1 Milestone 2 Milestone 3

Budget, Fees and Payment

Total Addendum Fee: $ Retainage:

Payment Schedule Additional Costs and Allowances

Change Order Procedure

No change to the Scope of Work, contract price, or schedule shall be binding unless authorized by a written Change Order signed by both parties. The Change Order shall state the reason for the change, the effect on cost, and the effect on schedule. If the Client directs work without a signed Change Order, the Service Provider shall provide a written cost and time estimate within days.

Change Order Approval Threshold Procedure Details

Insurance, Indemnity, and Risk Allocation

The Service Provider shall maintain insurance coverages consistent with the Project Agreement and shall procure additional coverage required specifically for the construction phase if necessary. The Service Provider shall indemnify and hold harmless the Client from claims arising from the Service Provider's negligence or breach of this Addendum, subject to any limitations agreed in the Project Agreement.

Insurance Requirements / Limits

Confidentiality

Each party will treat all non-public information obtained from the other party in connection with this Addendum as confidential and will not disclose such information except as required for performance or as required by law. Confidential information does not include information that is already publicly known or independently developed without use of the other party's confidential information.

Governing Law and Dispute Resolution

This Addendum will be governed by the laws of the state of . Any dispute arising under this Addendum shall be resolved in accordance with the dispute resolution provisions of the Project Agreement, except that parties may pursue equitable relief when necessary to prevent irreparable harm.

Notices

Notices under this Addendum shall be delivered to the following representatives by certified mail, courier, or overnight delivery:

Client Notice Contact Service Provider Notice Contact

Representations and Warranties

Each party represents and warrants that it has the authority to enter into this Addendum and that performance of its obligations under this Addendum will not violate any applicable law or existing agreement. The Service Provider warrants that services provided will be performed in a professional and workmanlike manner consistent with industry standards.

Final Provisions

This Addendum, together with the Project Agreement and any incorporated documents, constitutes the entire agreement between the parties with respect to the subject matter hereof. In the event of any inconsistency between this Addendum and the Project Agreement, the terms of this Addendum shall control to the extent of the inconsistency.

Execution of this Addendum may be in counterparts, each of which will be deemed an original and all of which together will constitute one instrument. Electronic signatures, including scanned or electronically transmitted signatures, have the same force and effect as original signatures for purposes of this Addendum.

Acknowledgment

By signing below, the parties acknowledge and agree that they have read and understand this Addendum and that the persons signing have authority to bind their respective parties.

Client:

By:

Date:

Service Provider:

By:

Date:

What the Project Management Construction Addendum Is

The Project Management Construction Addendum is a contract attachment that modifies or clarifies project-level terms for construction works, including scope adjustments, schedule updates, change-order routing, payment milestones, and site access rules. It sits alongside a primary construction agreement and records mutual amendments without replacing the main contract. Because it alters obligations and pricing, parties typically attach exhibits such as revised schedules, drawings, or cost breakdowns. The addendum can be executed on paper or electronically and should identify affected contract sections, effective dates, and signatures for all responsible parties.

Why a Construction Addendum Matters to Project Outcomes

A clear addendum reduces ambiguity, speeds approvals for change orders, and creates a focused record of what changed and why. It helps limit disputes by documenting scope, deadlines, and payment adjustments in one place and supports auditability when retained with primary contracts.

Which Project Roles Typically Complete the Addendum

Project managers, general contractors, owners, and subcontractors commonly prepare or sign construction addenda to reflect negotiated changes.

Owner representative — Confirms scope changes, approves budget and milestone dates, and signs for owner acceptance.
General contractor — Details revised work, coordinates subcontractor responsibilities, and updates the project schedule.
Subcontractor or supplier — Acknowledges changed scope, cost adjustments, and revised delivery or performance dates.

Ensure the person who signs has explicit authority under the primary contract and that the addendum references the original agreement by title and date.

Step-by-step: Completing the Addendum

Follow a concise sequence to prepare, review, and execute the addendum so responsibilities and timing are clear.

01

Draft: Describe changes, reference the original contract, attach revised exhibits.
02

Review: Circulate to affected stakeholders and project legal counsel for comments.
03

Approve: Obtain signatory authority confirmation and any required internal approvals.
04

Execute: Sign, date, and distribute executed copies to all parties and file in project records.

Common questions and problem resolution

Answers to frequently asked questions about execution, validity, and common errors when preparing a construction addendum.

Need help? Contact support

Can an addendum change the main contract?
Yes. A correctly executed addendum modifies the original agreement to the extent specified. Ensure the addendum references the original contract by title and date and is signed by authorized parties.
Is an electronic signature valid here?
Yes in most cases. Electronic signatures are enforceable under the ESIGN Act (15 U.S.C. ch. 96) and UETA where adopted; exceptions (wills, certain court filings) do not generally apply to construction addenda.
Who must sign the addendum?
Authorized signatories for each party must sign. Verify signature authority against the main contract or corporate authorization documents before execution to avoid later disputes.
Do I need a notary or witness?
Not typically required for ordinary contract amendments, but state or project-specific rules may require notarization for certain instruments or owner policies; check state or contract provisions.
What if a party refuses to sign?
Absent mutual agreement, unilateral changes are unenforceable. Document attempts to negotiate and consider alternatives such as change orders under existing change-management procedures.
How do I correct an executed addendum?
Create a new addendum that states it supersedes the prior one, or execute a mutual amendment that corrects the error and is signed by all original signatories.

Core components to include in a professional addendum

A well-structured addendum contains discrete sections that map changes to obligations, schedule, cost, and authority to sign.

Reference

Clear citation of the original contract by title, date, and parties so the amendment is legally tethered and enforceable as part of the contract record.

Scope

A precise, measurable description of added, removed, or modified work that prevents later interpretation disputes and supports change-order valuation.

Schedule

New milestone dates, float allocation, and any effects on critical path; include provisions for extensions and delay notice requirements.

Pricing

Specific cost adjustments, allowances, contingencies, and retainage changes including how additional costs will be invoiced and approved.

Approvals

A defined approvals chain for internal and external stakeholders, including who can authorize emergency or field directives and effective limits.

Signatures

Authorized signature blocks for each party with printed name, title, company, and date to evidence mutual acceptance of the modification.

Essential information fields to capture

Project name: Official contract identifier

Parties involved: Legal entity names

Change summary: Short scope description

Amount change: Dollar delta

Effective date: MM/DD/YYYY

Signatory details: Name, title, date

Common risks and potential consequences

Payment delay: Cashflow impact

Lien claim: Possible stop-payment

Permit noncompliance: Work stoppage risk

Schedule disputes: Delay damages

Cost overruns: Budgetary exposure

Invalid signature: Enforceability risk

Frequent preparation mistakes to avoid

Leaving vague language for scope changes produces differing interpretations and later claims; always quantify work and deliverables.
Failing to reference the original contract or exhibit can create ambiguity about which provisions remain in force and which are superseded.
Missing or incorrect signatory authority often leads to rejected payments or unenforceable amendments; confirm corporate signing limits in advance.
Neglecting to attach revised drawings or schedules forces disputes over what was actually changed; include clear exhibits and version numbers.

Where and how to route the executed addendum

Distribute executed copies to project stakeholders immediately and record the change in the contract management system.

Owner: Receives final executed copy for records and funding adjustments.
General contractor: Files with project documents and updates the schedule and budget.
Subcontractor: Gets a copy for scope and payment reconciliation.
Permitting agency: Submit if the change affects permits or code compliance.

Digital execution and platform considerations

Use a secure platform that supports signed PDFs, audit trails, and role-based access for multi-party execution.

File formats: PDF, DOCX supported
Integrations: Procore, Google Workspace, NetSuite
Authentication: Email, SMS, or SSO options

Confirm the chosen service can preserve an auditable history (timestamps, IP, signer identity) and retains executed copies in exportable formats for project records.

Practical tips for accurate and efficient completion

Adopt consistent templates and version controls to reduce errors and speed approvals.

Standardize templates

Use a single addendum template with numbered fields and attachment references so reviewers can compare versions quickly and reduce drafting inconsistencies.

Track versions

Assign version numbers and revision dates to every draft to prevent signing an outdated document and to maintain a clear change history.

Confirm authority

Verify signatory authority in writing before execution; require a board or delegated authority certificate for corporate signers when contract values exceed internal thresholds.

Preserve audit trail

When using electronic execution, capture signer identity, timestamps, and IP addresses, and store a signed PDF with its audit record for future disputes or audits.

File handling, export, and version control

Maintain exportable copies and clear version labels to ensure contract administrators can retrieve and present records when needed.

Export formats

Save executed addenda as PDF/A for long-term preservation and also retain editable DOCX copies for internal revision histories and redlines.

Version stamps

Mark each iteration with a version number and revision date in the header and file name to avoid confusion about which document is current.

Attachment control

Attach updated drawings, schedules, and cost exhibits with exhibit labels and ensure each attachment is referenced in the addendum text.

Audit trail

Keep an execution history showing signer identity, timestamps, and IP addresses to support enforceability and dispute resolution.

eSignature pricing and capability comparison

Common vendor features and starting prices for eSignature plans used to execute construction addenda; signNow is listed first for comparison consistency.

	signNow	DocuSign	Adobe Sign	PandaDoc	HelloSign
Starting Price	$8/user/mo	$15/user/mo	$14/user/mo	$19/user/mo	$15/user/mo
Free Trial	7-day free trial	Yes	Yes	Yes	Yes
Bulk Send	Yes	Yes	Yes	Yes	No
Audit Trail	Yes	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes	Yes	Yes	No	No

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