2D to 3D Architectural Model

Project description
I need an experienced freelancer to create an accurate exterior only 3D model of a house from two supplied PNG drawings.

I do not have CAD/vector files such as DWG, DXF or PDF, so the work must be carried out by tracing/interpreting the PNG images, which include plans, elevations and scale information. The PNGs are supplied at the highest resolution my software can produce (300 dpi), with deliberately thin line weights to assist accurate tracing.

Scope
exterior model only
no internal walls, rooms, furniture or landscaping
include all visible external architectural features shown on the drawings, including roof form, dormers, hips/cropped hips, gutters, projections, conservatory, doors, windows, porch etc.
The model must be drawn accurately from the supplied plans/elevations and scaled correctly from the provided scale information on each drawing.

Output required
OBJ file
MTL if applicable
native source/model file
STEP file if available would also be useful
plain white / simple material is fine
no colour rendering required

The OBJ will be used later in an online viewer such as 3dviewer.net.

Important
This must be a faithful 3D reconstruction from the supplied drawings, not a rough or AI-style approximation. I would like at least one interim preview before final delivery to confirm the geometry is being interpreted correctly.

IP / copyright
The house shown in the 2D drawings is my original design. The freelancer is engaged only to create the 3D model from my drawings. On payment in full, all rights in the created 3D model and associated deliverables are to be assigned to me. The work must not be reused, resold, published, shared, or included in any portfolio without my written permission.

Please include in your bid
fixed price
delivery time
revision rounds included (minimum one)
software you will use
examples of similar house / exterior 3D modelling work