Expandable Mobile Home Engineering and Design

# Mechanical / Structural Engineer for Expandable Mobile Home Platform — Two Layout Variants

**Project Location:** Rabat Region, Morocco
**Specialisation:** Trailer chassis engineering, expandable structures, mechanical design, structural analysis and fabrication-ready CAD drawings.

## Project Summary

We are developing a road-towable, double-expandable mobile home platform for local fabrication in Morocco. We need an experienced mechanical / structural / product engineer to design a **common engineering platform supporting two complementary layout variants**, with a target combined expanded area of approximately **100 m²**.

Both variants must share the same core engineering platform, including chassis dimensions, folding mechanism, steel structure, floor and roof systems, hinges, supports, insulation, sandwich panels, materials and manufacturing methodology.

**The objective is to reuse at least 50% of the engineering work between both variants**, with the second layout requiring primarily internal space adaptation and weight-distribution adjustments—not a completely separate engineering project.

## Basic Accommodation Requirements

**Module A — Night Unit**
- 3 bedrooms
- 1 master bedroom with private ensuite bathroom
- 1 shared bathroom serving Bedrooms 2 and 3

**Module B — Day Unit**
- Salon / living room
- Dining area
- Kitchen
- 1 guest WC / bathroom

**Total: 3 bedrooms and 3 bathroom facilities** (master ensuite, shared bathroom and guest WC/bathroom).

## Design Constraints and Priorities

The transport configuration is intended to use a compact, towable trailer platform, with a preliminary folded envelope of approximately **8.4 m long × 2.5 m wide per unit**, expanding to approximately **7.0 m wide on site**. These dimensions are the current design basis and must be checked against the final folding geometry, towing vehicle, running gear and applicable transport regulations.

The first priority is to optimise the functional layout around:

- Fixed structural core versus expandable/folding areas
- Practical room dimensions, circulation and furniture placement
- Bathroom, plumbing and kitchen wet-zone locations
- Chassis loading, axle loads and centre of gravity
- Left/right and longitudinal weight balance
- Folding-floor geometry, hinges, supports and locking mechanisms
- Weatherproofing, insulation and sound isolation
- Materials and fabrication methods available near Rabat, Morocco
- Durability in an approximate operating temperature range of 5–45°C

Where practicable, bathrooms, plumbing manifolds, kitchen services and other heavy components should remain within the fixed structural core. Lighter bedroom and living-space elements may use the expandable wings, subject to structural and operational validation.

## Scope of Work and Deliverables

**1. Functional Space Engineering**
- Dimensioned floor plans for both layout variants
- Fixed-versus-folding area diagrams
- Furniture, door and window layouts
- Bathroom and kitchen service coordination
- Weight-distribution concept and preliminary mass budget
- Folded, deployed and combined configurations

**2. Mechanical and Structural Engineering**
- Chassis frame, longitudinal beams and crossmembers
- Axle, suspension, wheel, braking and drawbar selection
- Structural steel sizing and connection design
- Folding floors, wall and roof framing
- Hinges, locking systems, mechanical stops and deployment supports
- Stabilising legs, lifting points and transport restraints
- Load cases, axle-load calculations, centre-of-gravity assessment and stability checks
- FEA where appropriate and supported by suitable boundary conditions

**3. Fabrication-Ready Documentation**
- Detailed 2D manufacturing drawings and 3D CAD assembly
- Steel member schedules, cutting lists and bill of materials (BOM)
- Welding symbols, weld details, bolt specifications and tolerances
- Hinge, locking, support and module-connection details
- Assembly sequence and fabrication methodology
- Material, insulation, sandwich-panel and waterproofing specifications
- Inspection and quality-control checkpoints

**4. Engineering Handover**
- Editable native CAD files and neutral exchange formats
- Coordinated PDF drawing package
- Engineering calculations and assumptions register
- Procurement and material take-off schedules
- Fabrication and installation notes
- Documentation suitable for review and approval by the responsible engineer before fabrication release

## Milestones

1. **Functional layout:** space distribution, room dimensions, fixed/folding zones and initial weight strategy.
2. **Client review and approval:** freeze the preferred arrangement before detailed structural design.
3. **Structural concept:** chassis, axles, framing, folding system and initial calculations.
4. **Engineering validation:** load assessment, weight balance, stability and mechanism verification.
5. **Fabrication package:** final coordinated drawings, BOM, cutting lists and manufacturing details.

The project is milestone-based. Each stage must be reviewed and approved before proceeding to the next.

## Required Experience

Applicants should have demonstrable experience in one or more of the following:

- Expandable tiny homes or mobile homes
- Trailer chassis and towing systems
- Folding or deployable structures
- Modular buildings and lightweight steel fabrication
- Mechanical product design and structural FEA

Proficiency in SolidWorks or equivalent professional CAD software is required.

## Proposal Requirements

Please include:

- Examples of comparable projects, especially completed fabrication drawings
- Your proposed engineering workflow and software
- Confirmation of which calculations and components you will personally engineer
- A fixed-price quotation broken down by milestone
- Estimated delivery schedule and revision allowance
- Any assumptions, missing information or critical risks you identify at the outset

**Important:** We require a coordinated engineering and manufacturing package—not just a conceptual floor plan or 3D render. The final design must be suitable for technical review and approval before fabrication. Transport legality, structural safety, axle/brake suitability and the expansion mechanism must be explicitly addressed.

## Reference Brief

Detailed requirements, reference images, room distributions, insulation, waterproofing, sound-isolation expectations and deliverables are provided in the attached Notion brief. Please review the brief before submitting your proposal.