Add dimensions to DWG and draw proposed extension

Description

I seek a skilled CAD technician to update architectural drawings for a home extension project. The existing drawings, provided as AutoCAD files, require dimensions added to fully specify the design. Additionally, a small rear extension is proposed based on a concept sketch.
The technician should open the DWG files and methodically add linear and radial dimensions consistent with technical drawing standards, fully defining the existing structure's geometry, spaces and elements. Dimensions must be placed precisely and labeled clearly using appropriate numbering protocols.
Once dimensioned, the drawings are to be augmented with a new section depicting the rear addition. Utilizing the schematic diagram as a reference, the extension area should be carefully drawn to scale replicating wall alignments, any openings illustrated, and relevant notations on materials. Internal partitions or fixtures are not required at this stage.
The completed drawings set will undergo approval to support a planning application in the United Kingdom. Therefore, an expert understanding of dimensioning conventions and presentation suitable for local authority assessment is important. The format must be neat, thoroughly dimensioned and labeled, with a professional appearance reflective of someone experienced in technical architectural graphics.
Original .dwg to be provided after initial engagement.