Generally foundations for domestic extensions are sized in accordance with the Building Regulations and agreed with the approved building control inspector.
For bespoke properties or where there are problematic ground conditions present a Chartered Structural Engineer would be required to provide advice on the type of foundation and the production of structural calculations and drawings. Often raft foundations or piled foundations are required, CVM can provide cost effective solutions for all types of foundation design.
Utility pipes such as drains can also be present beneath your site, CVM have extensive experience of dealing with statutory authorites such as STWA or United Utilities to achieve solutions to this problem.
CVM would generally work from your extension or house plans to determine a suitable foundation design and provide calculations and details to be submitted to building control.
CVM can provide an initial fee quotation over the phone, however, it is always recommended that the site be visited by an engineer provide an initial assessment prior to this.