Can a Design Project Addendum be signed electronically?

Yes. Electronic signatures are generally legally enforceable under the federal ESIGN Act (15 U.S.C. ch. 96, 2000) and state UETA statutes where adopted, provided the parties demonstrate intent, consent, attribution, and retention capabilities.

Is notarization required for an addendum?

Not usually required for typical contract amendments, but some jurisdictions or specific contract provisions may require notarization or witnesses; confirm local law and any lender or permitting conditions before execution.

What if one party refuses to sign the addendum?

If a party refuses, the original contract governs until a mutually executed modification exists. Consider negotiation, dispute-resolution provisions, or issuing a written change order per the contract's allowed procedures.

How should cost overruns be handled in the addendum?

State the method for calculating additional costs, include supporting breakdowns or hourly rates, and specify payment timing to reduce later disagreements and enable prompt invoicing.

Who is authorized to sign on behalf of a company?

A signatory must have express authority under the company’s bylaws or the original contract; verify signer title and, if necessary, a board resolution or officer certificate to confirm authority.

How do I document subsequent revisions to the addendum?

Use numbered revision exhibits, dated version control, and execute each revision with the same formalities as the original addendum to maintain a clear audit trail.

Electronic Signature
Templates
Miscellaneous
Design Project Addendum

Design Project Addendum

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

DESIGN PROJECT ADDENDUM

This Design Project Addendum ("Addendum") is entered into as of the Effective Date set forth below by and between Client Name: and Designer Name: . This Addendum amends and supplements the original design services agreement identified below.

Recitals

WHEREAS, the parties entered into a Design Services Agreement titled Original Agreement Title: dated (the "Agreement");

WHEREAS, the parties desire to modify the scope and terms of the Agreement to include additional design services and deliverables for the Project identified as Project Name: .

WHEREAS, the parties agree that the terms of this Addendum shall govern to the extent of any conflict with the Agreement.

Scope of Work

Detailed Scope of Additional Services

Deliverables to be provided by Designer (describe schedule and format):

Change Orders

Any material changes to the Scope of Work shall require a written change order executed by both parties. Additional fees and revised schedules resulting from approved change orders will be set forth in the written change order and shall become part of this Addendum.

Change order required for additional services: Yes

Payment Terms

Additional Compensation (USD) Payment Schedule Invoicing and Due Date

Designer will submit invoices to Client. Payment is due within days of invoice receipt.

Late Fee

Overdue amounts shall bear interest at the lesser of (a) per month or (b) the maximum rate permitted by applicable law, plus reasonable collection costs.

Term and Termination

This Addendum shall commence on Effective Date: and shall continue until Completion Date: unless earlier terminated in accordance with this section.

Either party may terminate this Addendum for material breach by the other party if the breaching party fails to cure the breach within days after written notice. Either party may terminate for convenience upon days' prior written notice.

Upon termination, Designer shall deliver to Client all completed deliverables and work-in-progress for which Client has paid. Client shall pay Designer for services performed through the effective date of termination in accordance with the Payment Terms.

Confidentiality

Each party shall keep confidential and shall not disclose to any third party any Confidential Information of the other party. "Confidential Information" means non-public business or technical information disclosed in connection with the Project, including designs, specifications, pricing, trade secrets and deliverables. Confidential Information does not include information that is (a) already lawfully known by the recipient; (b) publicly available without breach of this Addendum; or (c) independently developed without use of the disclosing party's Confidential Information.

The receiving party shall use at least the same degree of care to protect the disclosing party's Confidential Information as it uses to protect its own confidential information, but in no event less than reasonable care. Disclosure required by law is permitted only after prompt written notice to the disclosing party and, where lawful and practicable, assistance in seeking protective measures.

Intellectual Property

Unless otherwise agreed in writing, Designer grants to Client a non-exclusive, non-transferable license to use final deliverables for the Project's intended purpose. Designer retains ownership of drafts, preliminary work, and underlying methodologies. Any transfer of ownership or assignment of intellectual property rights shall be set forth in a separate written instrument signed by both parties.

Warranties and Liability

Designer warrants that services will be performed in a professional manner consistent with industry standards. EXCEPT AS EXPRESSLY PROVIDED IN THIS ADDENDUM, DESIGNER DISCLAIMS ALL OTHER WARRANTIES, WHETHER EXPRESS OR IMPLIED. IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR INDIRECT, CONSEQUENTIAL, OR PUNITIVE DAMAGES. THE PARTIES' AGGREGATE LIABILITY FOR ANY CLAIM ARISING OUT OF THIS ADDENDUM SHALL NOT EXCEED THE FEES PAID TO DESIGNER UNDER THIS ADDENDUM.

Governing Law

This Addendum shall be governed by and construed in accordance with the laws of the State of without regard to conflict of law principles.

Entire Agreement; Amendment

This Addendum, together with the Agreement, constitutes the entire agreement between the parties with respect to the subject matter hereof and supersedes all prior negotiations and understandings. Any amendment to this Addendum must be in writing and executed by authorized representatives of both parties.

Notices

Client Notice Contact Designer Notice Contact

Miscellaneous

If any provision of this Addendum is held invalid or unenforceable, the remaining provisions shall remain in full force and effect. The parties acknowledge that they have had the opportunity to consult counsel and that this Addendum shall not be construed against either party by reason of authorship.

Client:

By:

Date:

Designer:

By:

Date:

What a Design Project Addendum Is and When It Applies

A Design Project Addendum is a written amendment to an existing design contract that documents changes to scope, fees, schedule, deliverables, or responsibilities. It creates a binding modification when executed by authorized parties and typically attaches as an exhibit to the original agreement. Addenda record change orders, clarify ambiguities, and preserve the contractual chain for claims or permitting. When signed and retained, the addendum becomes part of the project record and should reference the original contract, identify affected drawings or specifications, and state any price or time adjustments.

Why a Clear Addendum Protects Project Outcomes and Rights

A properly drafted Design Project Addendum reduces disputes by documenting exact scope, cost, and schedule changes; it establishes mutual consent and preserves remedies. Electronic execution is generally enforceable under the federal ESIGN Act (15 U.S.C. ch. 96, 2000) and state UETA frameworks where adopted.

Who Typically Prepares and Signs a Design Project Addendum

Several parties commonly prepare or approve a design addendum; understanding roles helps ensure the document is valid and actionable.

Design firms and lead architects who document scope revisions and deliverable changes for client approval.
Project owners or developers approving budget, schedule, or specification changes and providing formal acceptance.
General contractors and specialty subcontractors acknowledging coordination changes, access, or phasing adjustments.

Ensure signatures come from individuals with authority under the original contract and that signatory names match corporate records to avoid later disputes.

Core Elements Every Professional Addendum Should Include

A concise, structured addendum increases enforceability and reduces ambiguity; include identifiers, clear change language, and reference exhibits.

Amendment Summary

A brief overview stating this document amends the original contract, including original contract date and parties to eliminate confusion and preserve audit trails.

Scope Changes

Explicitly describe added, removed, or revised tasks, deliverables, drawings, and performance standards so obligations and expectations are unambiguous for all stakeholders.

Cost Adjustment

State any increases or credits with payment timing, invoicing references, hourly rates if applicable, and calculation method for change order amounts.

Schedule Impact

Document revised milestones, completion dates, or phasing changes and any acceleration or delay responsibilities tied to the change.

Attachments

List and attach revised drawings, specifications, cost breakdowns, and referenced exhibits, including revision numbers and dates for clarity.

Execution Blocks

Provide signatory lines with printed name, title, company, date, and witness or notary fields where required to ensure a valid signature process.

Essential Data to Capture in the Addendum

Parties: Legal entity names

Project ID: Contract or project number

Effective Date: MM/DD/YYYY

Change Summary: Concise description

Monetary Terms: Dollar amounts

Signatures: Signer name and title

Step-by-Step: How to Complete a Design Project Addendum

Follow these steps to prepare, review, and execute an enforceable addendum that ties cleanly to the original contract.

01

Review Original: Confirm contract clauses that limit or require specific amendment procedures.
02

Draft Changes: Write clear scope, cost, and schedule language and attach exhibits.
03

Internal Approval: Obtain required internal approvals before sharing with counterparty.
04

Execute: Have authorized signers sign and date; retain copies for records.

How to Configure an Online Addendum Workflow

Set up a repeatable digital workflow to collect signatures, track approvals, and store the executed addendum with its exhibits.

Field	Configuration
Signer Order	Sequential or parallel signing
Authentication	Email link, SMS code, or stronger MFA
Attachments	Lock exhibits after upload
Audit Trail	Enable time-stamped logs

Where to Send and File the Executed Addendum

Confirm distribution recipients and archival locations to maintain a single source of truth and meet contractual notice requirements.

Client Copy: Send final PDF to owner and project manager
Design Team: Distribute to lead architect and consultants
Contractor: Provide signed addendum to general contractor
Project File: Store executed copy in project records repository

Technical Considerations for Digital Execution

Choose tools that preserve document integrity, generate an audit trail, and support the file formats used on your project.

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

Ensure the vendor provides tamper-evident PDFs, retention options, and the ability to export audit trails for compliance or dispute resolution.

Typical Timelines and Response Deadlines

Design addenda often trigger time-sensitive actions; set clear deadlines for approvals and payment adjustments to avoid schedule slippage.

Effective Date:

Date change obligations begin

Approval Window:

Respond within 7–14 business days

Payment Terms:

Invoice due within 30 days unless stated

Permit Submission:

Submit revised documents per local authority timelines

Record Retention:

Keep executed addendum with contract file

Common Mistakes to Avoid When Preparing an Addendum

Using vague language about scope or deliverables that creates multiple interpretations and later disputes.
Failing to reference the original contract date and section numbers, making it hard to reconcile obligations during claims.
Allowing unsigned or partially executed pages to circulate without a clear audit trail or completion certificate.
Not obtaining signatures from authorized signatories or failing to confirm corporate signing authority before execution.

Risks and Consequences of an Incorrect Addendum

Delay Claims: Schedule impacts

Payment Disputes: Unpaid change orders

Breach Risk: Contractual liability

Permit Rejection: Noncompliant documents

Increased Costs: Unallocated overruns

Tax Issues: Reporting complications

Comparing eSignature Options for Executing a Design Project Addendum

Choose an eSignature vendor that meets security, compliance, and workflow needs; the table below compares basic plan, trial, bulk send, audit trail, HIPAA capability, and envelope limits.

	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	Varies by plan	Varies by plan	Limited trial available	Limited trial available
Bulk Send	Yes	Yes	Yes	Yes	No
Audit Trail	Yes	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes	Yes	Yes	No	No

Key Project Milestones After Issuing an Addendum

A sequence of milestones helps track completion and integration of the change into project schedules and permits.

01

Issue Addendum

Sender issues the addendum and supporting exhibits to recipients.

02

Internal Review

Each party completes internal approvals or cost verification.

03

Counterparty Approval

Authorized signer executes or returns comments within the approval window.

04

Update Records

Incorporate changes into drawings, schedules, and the document repository.

Frequently Asked Questions About Design Project Addenda

Answers to frequent questions about enforceability, notarization, digital execution, and dispute handling for addenda to design contracts.

Need help? Contact support

Can a Design Project Addendum be signed electronically?
Yes. Electronic signatures are generally legally enforceable under the federal ESIGN Act (15 U.S.C. ch. 96, 2000) and state UETA statutes where adopted, provided the parties demonstrate intent, consent, attribution, and retention capabilities.
Is notarization required for an addendum?
Not usually required for typical contract amendments, but some jurisdictions or specific contract provisions may require notarization or witnesses; confirm local law and any lender or permitting conditions before execution.
What if one party refuses to sign the addendum?
If a party refuses, the original contract governs until a mutually executed modification exists. Consider negotiation, dispute-resolution provisions, or issuing a written change order per the contract's allowed procedures.
How should cost overruns be handled in the addendum?
State the method for calculating additional costs, include supporting breakdowns or hourly rates, and specify payment timing to reduce later disagreements and enable prompt invoicing.
Who is authorized to sign on behalf of a company?
A signatory must have express authority under the company’s bylaws or the original contract; verify signer title and, if necessary, a board resolution or officer certificate to confirm authority.
How do I document subsequent revisions to the addendum?
Use numbered revision exhibits, dated version control, and execute each revision with the same formalities as the original addendum to maintain a clear audit trail.

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