An initial meeting with the client to discuss their requirements, budget, risks and agree the best team to put in place.

Prepare a project specific brief highlighting information requirements i.e. topographic surveys, environmental studies etc. Undertake feasibility studies to verify whether a site can accommodate the client’s needs.

Develop conceptual layout between Architect and Engineer:

• Preliminary site grading including an assessment of earth retaining structure requirements, but no analysis of the structures will be undertaken.
• Preliminary earthworks analysis (cut and fill) based on existing ground elevations and preliminary grading elevations.
• Preliminary road alignments/profiles to prove concept and inform the site grading and earthworks analysis.
• Preliminary drainage layout to prove concept. No detailed analysis will be undertaken to size the pipework.
• Swept Path Analysis to prove concept.

Conceptual layout driven forward to Stage 4 Technical Design by both Architect and Engineer:

• Site grading will now include building footprint finished floor levels, profiles for earth retaining structures and any other obstruction that would affect grading.
• A detailed earthworks analysis will be undertaken which will consider site strip, depth to formation level, earth retaining structures, building footprints etc. This will follow a comprehensive ground investigation where material type, reusability and foundation recommendations will be detailed by a Geotechnical Engineer.
• Road alignments/profiles will be refined to include changes in cross section, junctions and pavement construction.
• Hydraulic capacity calculations will be performed to BS EN 752 which includes the ‘flat rate of rainfall’ method for assessing the peak discharge of surface water and is suitable for drains that do not exceed 200m in length. This assumes a flat rate of rainfall of 50mm/hour. This rainfall intensity is regarded as satisfactory by most regulatory bodies. The surface water analysis will not be run as a simulation.
• The foul drainage will be sized using a minimum pipe diameter of 150mm and a minimum gradient of 1:60 for up to 9 connected properties and a minimum gradient of 1:150 for at least 10 connected properties.
• Prepare and submit planning application and review the design against Building Regulations.

All Road design will be in accordance with Design Manual for Roads and Bridges (DMRB), Designing Streets and Local Authority guidelines.

All Drainage Design will be in accordance with Sewers for Scotland, Sewers for Adoptions, BS EN 752 and all other relevant guidelines.

Soakaway design in accordance with the Building Regulations:

• Scottish Government: Building Standards Division: Domestic Technical Handbook
• England: The Building Regulations 2010: Drainage and Waste Disposal, Approved Document H