CHANGE ORDER #001
Project: Riverside Middle School – Classroom Wing Renovation
Location: 4250 Education Boulevard, Austin, TX 78704
Owner: Riverside Independent School District
Contractor: Apex Construction Group, LLC
Date: November 10, 2025
Prepared By: Daniel Baron, Project Manager
CONTRACT VALUE SUMMARY
| Item |
Amount |
| Original Contract Sum |
$487,500.00 |
| Previous Change Orders (Net) |
$0.00 |
| This Change Order |
$9,684.00 |
| Revised Contract Sum |
$497,184.00 |
SCOPE OF CHANGE
Change Description
The Owner has directed a change from standard 1-3/4″ hollow metal classroom doors (per Section 08 11 13) to STC 45-rated acoustic door assemblies with upgraded perimeter seals, automatic door bottoms, and heavy-duty hinges. This upgrade enhances classroom sound isolation to meet educational acoustic performance standards not specified in the original contract documents.
Document References
- Specification Section 08 11 13 – Hollow Metal Doors and Frames
- Specification Section 08 35 00 – Acoustic Doors and Frames (added by owner directive)
- Owner Directive dated November 7, 2025
- Drawing Reference: Door Schedule Sheets A-801 through A-804
- Architect Email dated November 8, 2025 (confirming acoustic rating requirement)
ORIGINAL vs REVISED REQUIREMENTS
Original Requirement (Per Contract Documents)
Standard 1-3/4″ thick hollow metal doors, 18-gauge steel face, mineral core, standard hardware set (non-acoustic), installed in standard hollow metal frames. Doors D-201 through D-208 (8 classrooms on second floor).
Original Specification:
- Door leaf: 1-3/4″ HM, 18-gauge, mineral core
- Frame: 16-gauge HM, standard knock-down
- Hardware: Standard mortise lockset, ball-bearing hinges, surface closer
- Performance: Standard sound attenuation (no STC rating specified)
Revised Requirement (Per Owner Directive)
STC 45-rated acoustic door assemblies, 2″ thick solid core with acoustic seals, heavy-duty continuous hinges, automatic drop bottoms, and upgraded frame gasketing. Doors D-201 through D-208 (same 8 classroom locations).
Revised Specification:
- Door leaf: 2″ thick, solid core, STC 45-rated assembly
- Frame: 16-gauge HM with perimeter acoustic gasket system
- Hardware: Acoustic-rated mortise lockset, heavy-duty continuous hinges, surface closer, automatic door bottom
- Performance: STC 45 minimum (tested assembly rating)
MATERIALS IMPACT
Materials Added
| Item Description |
Qty |
Unit |
Unit Cost |
Extended Cost |
| Acoustic-rated door & frame assemblies (STC 45) |
8 |
EA |
$950.00 |
$7,600.00 |
| Acoustic perimeter seal kits |
8 |
EA |
$145.00 |
$1,160.00 |
| Automatic door bottoms (adjustable) |
8 |
EA |
$110.00 |
$880.00 |
| Subtotal Materials Added: |
$9,640.00 |
Materials Deleted (Credit)
| Item Description |
Qty |
Unit |
Unit Cost |
Extended Cost |
| Standard hollow metal door assemblies |
8 |
EA |
$480.00 |
($3,840.00) |
| Subtotal Materials Credited: |
($3,840.00) |
Net Materials Cost: $5,800.00
LABOR IMPACT
Labor Added
| Task Description |
Hours |
Rate |
Extended Cost |
| Install upgraded acoustic seals and drop bottoms |
16 |
$72/hr |
$1,152.00 |
| Frame modification and alignment for thicker doors |
8 |
$72/hr |
$576.00 |
| Subtotal Labor Added: |
$1,728.00 |
Net Labor Cost: $1,728.00
Labor Justification:
STC 45-rated door assemblies require precision installation of multi-component acoustic seal systems (head, jamb, threshold, and automatic door bottom). These systems must be carefully aligned and adjusted to maintain acoustic performance. Additionally, 2″ thick door leaves require frame head and jamb modifications to accommodate increased door weight and thickness, adding 8 hours of carpentry labor for alignment and shimming.
EQUIPMENT & OTHER DIRECT COSTS
| Item Description |
Qty |
Rate |
Extended Cost |
| Specialized routing tools for seal prep (consumables) |
1 |
– |
$120.00 |
| Field acoustic testing (verification, optional but recommended) |
1 |
– |
$300.00 |
| Subtotal Equipment/Other: |
$420.00 |
SCHEDULE IMPACT
Schedule Impact: +2 calendar days (minor adjustment for frame modifications and seal installation)
Extended General Conditions: 2 days @ $125/day = $250.00
Schedule Justification:
Acoustic door assemblies require additional fabrication time (2 weeks longer than standard doors) and precision field installation. Frame modifications and seal system installation add approximately 2 days to the door installation schedule. This minor extension does not impact the overall project substantial completion date, as it occurs within existing float on the interior finishes schedule.
COORDINATION IMPACT
| Coordination Item |
Cost |
| Door frame modification coordination with drywall and hardware trades |
$300.00 |
| Additional shop drawing revisions and acoustical hardware submittal review |
$250.00 |
| Subtotal Coordination: |
$550.00 |
Coordination Justification:
Acoustic assemblies require hardware coordination (continuous hinges, threshold seals, automatic door bottoms) not included in original hardware submittal. Additional shop drawing cycle required for architect approval of acoustic assembly details. Drywall contractor must coordinate frame depth and installation sequence to accommodate upgraded frame gasket system.
COST SUMMARY
| Category |
Amount |
| Materials (Net) |
$5,800.00 |
| Labor (Net) |
$1,728.00 |
| Equipment & Other |
$420.00 |
| Schedule Impact |
$250.00 |
| Coordination |
$550.00 |
| Subtotal (Direct Costs) |
$8,748.00 |
| Overhead & Profit (10.7%) |
$936.00 |
| TOTAL CHANGE ORDER |
$9,684.00 |
JUSTIFICATION & BACKUP
Cost Justification
Material Upgrade Justification (Performance Change):
Per Owner Directive dated November 7, 2025, and Architect confirmation dated November 8, 2025, the required door assemblies have been upgraded to achieve STC 45 acoustic performance. This performance standard was not specified in the original contract documents (Section 08 11 13 specified standard hollow metal doors with no acoustic rating requirement).
Acoustic-rated door assemblies carry significantly higher material costs due to:
- Thicker, denser door cores (2″ vs 1-3/4″, solid vs mineral core)
- Specialized acoustic gasket systems (perimeter seals, automatic door bottoms)
- Tested and certified assemblies (STC 45 rating requires UL-tested assembly)
- Premium hardware components (heavy-duty continuous hinges rated for heavier doors)
Standard hollow metal doors cost approximately $480 per assembly. STC 45-rated acoustic assemblies cost approximately $950 per assembly, representing a 98% material cost increase for this performance upgrade.
Labor Impact Justification:
Acoustic door assemblies require precision installation beyond standard hollow metal door installation:
1. Seal System Installation (16 hours total):
- Perimeter gaskets must be precisely aligned to maintain continuous seal
- Automatic door bottoms require adjustment and testing (2 hours per door)
- Threshold seals must coordinate with finish floor elevations
2. Frame Modifications (8 hours total):
- 2″ thick doors require frame head shimming and alignment
- Heavier door weight (75 lbs vs 55 lbs) requires structural verification
- Frame depth coordination with thicker door leaf
Standard hollow metal door installation: 1.5 hours per door (12 hours total)
Acoustic assembly installation: 3.5 hours per door (28 hours total)
Additional labor: 16 hours @ $72/hr = $1,152
Plus 8 hours frame modification @ $72/hr = $576
Total additional labor: $1,728
APPROVAL & ACCEPTANCE
Contractor Certification:
I certify that the costs outlined in this change order represent a fair and accurate accounting of the additional costs required to execute the scope change described above. This change order reflects the actual cost impact of changing from standard hollow metal doors to STC 45-rated acoustic assemblies, including materials, labor, coordination, and schedule impacts.
Contractor: _________________________________
Name/Title: Daniel Baron, Project Manager
Date: ______________
Owner/Architect Approval:
The above change order is approved for execution. The contract sum and contract time are hereby modified as indicated.
Owner: _________________________________
Name/Title: _________________________________
Date: ______________
Architect: _________________________________
Name/Title: _________________________________
Date: ______________
SUPPORTING DOCUMENTATION
Available upon request:
- Specification Sections 08 11 13 & 08 35 00
- Owner directive dated November 7, 2025
- Architect email dated November 8, 2025
- Manufacturer product data sheets (STC 45 door assemblies)
- Vendor quotes (acoustic doors, seals, automatic door bottoms)
- Labor productivity data (acoustic assembly installation times)
END OF CHANGE ORDER DOCUMENT