Castria is a multi-disciplinary firm which was established and remains in Cornwall now further expanding the skills we have honed from working in marine and land based projects. We now offer these specialist skills to private, government, defence & charitable organisations throughout the United Kingdom; to learn more about this and some of the fascinating projects we have and remain involved with in England, Scotland & Wales please follow the link to our main website

However, for those of you requiring our services in Cornwall you can rest assured our roots have remained firmly bedded in Cornwall where our staff enjoy the benefits of living in this very special County as well as putting back into the community with voluntary roles in sports clubs, RNLI, Scouting & Air Cadets; we are therefore ideally placed to understand and serve our Cornish based Clients from the home owner through to infrastructure projects that provide access into the rest of the UK as well as abroad, not forgetting our ongoing work on the IoS.

Richard Benwell a Chartered Building Surveyor joined us this year having run his own Firm for 21 years so that we could not only offer a fully integrated design service, but also to assist with our maintenance and repair projects. Richard’s dedication to his Profession is evident in the enthusiasm shown on each and every project he works on and compliments that of the other like minded professionals that work alongside him; Meet the Team – Click Here.


All services offered by Castria are fully tailored to your needs to ensure a personal service is always delivered whilst you benefit from having the fully integrated range of professionals to assist as and when required, this is embedded in our ethos of ”treat others as you would wish to be treated”. Please feel free to contact Richard to discuss your proposal, whether it be concerns over movement or proposed structural alterations to you home or something similar to other schemes we have worked on: design of aircraft hangers, repairs to dry docks, pontoons, conservation work to Listed Buildings and Scheduled Monuments or design of contemporary homes, offices and more recently combining Contemporary Design with Listed Buildings so as to make them economically viable for the building’s owner. The words a Client once said, must no longer continue to ring true – “You are Cornwall’s best kept secret!”.


The introduction of a Building Surveying Division enables Castria to take on a wider variety of work encompassing jobs from defects analysis for an individual through to condition reports and maintenance programmes for housing providers, charitable organisations, education providers and defence contractors.

Within Castria the Building Surveying Division/Department/Service has the ability to work autonomously undertaking traditional Building Surveying work whilst also being integral to Castria’s ethos of collaborative working between their Architects, Engineers and Surveyors, thus ensuring that our Clients benefit from a wide breadth of experience. Our Clients will also enjoy direct access to the person undertaking their instruction, in addition to having the peace of mind that they will also benefit from the extensive breadth of experience within Castria that the Surveyor can draw upon to deliver the instruction in a prompt and professional manner. Please feel free to contact Richard Benwell a Chartered Building Surveyor with a wide breadth of experience in both modern and traditional forms of construction.


We specialise in the rapid production of specific defects and assessment of potential structural defects. These may result from an item identified in an acquisition survey that requires additional investigation or visual evidence such as cracking occurring within walls, pooling of water, deflection of a roof slope, movement in retaining walls to name but a few. Castria being a multidisciplinary practice will have the person to assist you with not only the diagnosis, but to provide you with the peace of mind or a plan of action to resolve the issue.





Castria undertakes Civil Engineering services across the southwest and further afield. Working as part of a multi-disciplinary practice encompassing structural engineering and architectural design ensures that Civil Engineering requirements form a key part of the design process from an early stage.

Castria Civil Engineering Department are able to offer the following services:

  • Full drainage design service to both private and adoptable schemes and section agreements

  • Drainage condition surveys

  • Flood Risk Assessments and Drainage Strategies

  • Highway and Residential Estate Road design including section agreements.

  • Site surveys and feasibility reports

  • Confined space surveys

  • Expert Witness advice and reports

Castria Design works closely with a number of trusted sub-consultants and where required are able to include the following services:

  • Geotechnical Site investigations

  • Contamination reports

  • Traffic Assessments

  • Topographical Surveys

When a project reaches the Construction stage, Castria Design are also able to undertake the following:

  • Site inspections

  • Contract administration

  • Project management



Our structural engineers have a wide breadth of experience in both design and defects analysis. If you are considering a new build, extension, structural alterations/layout changes we can deliver the service that you require. Our work encompasses both residential and commercial buildings from new build to Listed Buildings and scheduled monuments, therefore we have the skills and experience to deliver you a solution. Please do not feel that asking us to undertake inspection and calculations for the removal of a wall in your home is not a project we will excel at, with the number engineers we have at our disposal you will be pleased find that not only are our fees competitive, but our lead in period is frequently shorter than that of many small Engineering Firms. We pride ourselves on delivering a prompt and professional service.




Our talented architects, designers and technicians are experienced in residential, commercial and hospitality projects. We can add value to clients looking to develop new build projects.

We are specialists in improving and adapting heritage properties.


  • Concept design and visualisation
  • Planning Applications, Heritage Statements, Heritage Impact Assessments and Listed Building Consent Applications
  • Building Regulations
  • Technical Design and Specification
  • Tender Preparation


It is becoming a regular part of the property acquisition process that Lenders are requiring further investigations including “Visual Inspection (Mining & Ground Stability) Reports” as part of their lending requirements.


A “Mining Search” or “Mining & Ground Stability Search” is a routine part of solicitors and conveyancers pre-purchase enquiries of both property and land purchases. The purpose of these ‘desktop Searches’ is to collate known information about mining and ground features (both manmade and natural) that are in a proximity of the acquisition that may have an effect upon the stability and in turn viability/value of the purchase.

There are usually three recommendations resulting form “Mining Searches” & “Mining & Ground Stability Searches” which are as follows:

  1. Pass/No Further Action
  2. Visual Inspections (typically undertaken by our Building Surveyors) result from natural ground features or manmade activities that may create differing ground bearing capabilities, these can result in differential movement/subsidence and in turn damage to structures built upon it. The purpose of the Visual Inspection is to ascertain if there are structural defects or ground movement that could be attributable to the identified features; if such movement is identified it is likely that Invasive Investigations/Further Investigations will need to need to be undertaken.
  3. Invasive Investigations/Further Investigations (typically undertaken by our Structural Engineers or Civil Engineers) will need to be undertaken to ascertain if remedial work will be required, these generally take the form of drilling and/or excavations. The most common cause of this is following manmade activities such as mining or infilled land in the immediate area.


Radon gas is a naturally occurring and invisible radioactive gas, it can build up in properties in particular where there is lower ground accommodation or where they are left for periods of time without occupation, in the worst cases this can become a safety hazard. It is finally becoming routine practice that buildings are being tested for the presence of Radon Gas so that it does not become an issue during the sales process, if testing is required this should ideally be undertaken for a period of 3 months, for further information on testing please refer to Public Health England’s Site UKradon – Measuring radon. Where testing is required during the sale of a Property in order not to delay the sale by 3 months your Legal Adviser can organise a Radon Bond. If upon completion of the Radon Test it is found that the building has a reading in excess of the UK Action Level of 200 Bq m-3, please feel free to contact our office to discuss remediation measures.




Richard’s dedication to his Profession is evident in the enthusiasm shown on each and every project he works on. All services offered by Castria are fully tailored to your needs to ensure a personal service is always delivered and that the Client receives the service that they are expecting.

The majority of the workload we receive is from returning or referred customers – testament to our commitment to our clients.

We specialise in a number of reports, surveys and investigations for domestic and commercial clients including:

  • Structural appraisals
  • Schedules of conditions
  • Defect analysis
  • Listed Building advice, including adaptations and extensions
  • Structural calculations
  • New build design
  • Project management
  • Contract administration
  • Insurance reinstatement works
  • Planning and building control
  • Design work and remedial work of structures within a marine environment
  • Civil Engineering follow this link to understand more about drainage, flood mitigation, road design, suspended and retaining structures
  • Architectural and building conservation services

Richard Benwell


Defect Analysis


Richard Benwell - Castria

Office 11
Chi Tevyans
Trevenson Park
TR15 3FY

Call Our Freephone Number: 0800 2888 669

Your contact details will not be used for marketing or passed to any third parties 

Follow Us



Get In Touch

0800 288 669



Find Us

Office 11,
Chi Tevyans,
Trevenson Park,
TR15 3FY