How Long Does A Structural Engineer’s Inspection Take?
A structural inspection needs to be appropriate for the level of involvement required from the structural engineer. Typically you can expect this to be around an hour but this is dependent on a number of factors but broadly comes down to: “What Is The Scope?”
Let’s get a bit more detailed (engineers LOVE detail). There is often confusion regarding an inspection for the purpose of inspecting damage.
Crack Inspections
If the purpose of the structural engineer's visit is to inspect crack damage to the property then this will be dependent on a number of factors:
How widespread is the damage?
Is it restricted to a small part of one room or is cracking present to more, or all, of the property. Whilst the whole property will still be viewed, the worst-case damage will be the focus with other areas inspected for signs of consistency, or otherwise, with the main damage.
What is the type and size of the property?
Obviously a larger property will likely have more rooms to inspect, and thus take longer.
A self-contained house should be freer to be fully inspected. Whilst a self-contained flat in theory presents the same opportunity to inspect throughout, it may be necessary to inspect other adjacent flats to fully determine the nature of the damage within the subject flat. Access to this is largely out of the client’s control and so the full picture may not be possible. Similar is true of a House in Multiple Occupation (HMO) where access to all the rooms may not be possible.
[This is not the place to go into detail about what an HMO is and you can find plenty of details on your local council or government websites but a house in multiple occupation, also known as a house of multiple occupancy, is usually a residential property that has been subdivided and lived in by more than one household where the households all share common areas such as the kitchen, bathroom and any reception room.]
Is the damage progressive?
Has the damage been getting worse since being first noticed? Is it cyclical (do the cracks open and close throughout the year)? Has the damage, broadly, been the same?
As such, an inspection of crack damage to a property could take anywhere from 30 minutes, for a straightforward issue and assessment, to a few hours.
Any advice, anecdotal or otherwise, regarding the above will help the engineer determine what access will be required and so avoid the need for abortive or ineffective time spent on site and so reduce the need for return visits and so limit the overall length of the visit.
Design Inspections
If the purpose of the structural engineer's visit is to develop a scheme of structural alteration and / or extension then this will be dependent on a number of factors, similar in nature to the crack damage inspection:
What is the nature of the works?
A confirmation of the loadbearing (or non-loadbearing) nature of a wall will likely be quicker than taking basic measurements in order to design a beam or frame for a opening in a single wall.
Both the above will be quicker than more widespread internal alterations combined with a rear and / or loft extension due to the number of affected elements that will need to be reviewed and noted.
What is the level of complexity of the project?
Even within the broad categories above, there may be complexities involved:
large column-free spaces required,
continuous ceilings needed where beams and frames are to be installed,
large expanses of sliding or folding glass doors
changes in level between existing suspended floors and proposed flooring
presence of trees adjacent to any extension works.
These will largely affect the design rather than the inspection but may affect what elements need to be inspected at the time of the initial visit.
Do you have drawings of the existing property and your proposals?
This will help determine the likely works involved and so allow the engineer to provide the following mark ups prior to attendance:
Areas where opening up investigations (to determine the size and direction of the structure being supported) and trial pits (to determine the depth and form of the existing foundations of the structure and those adjacent, where necessary).
A preliminary scheme to indicate the likely implications of your proposals, as well as give a basis of the scope of the fee.
What is the type of the property?
Similar access restrictions as those noted for the inspection may mean more or less time is required on site. They may also determine the type of investigation works that can be carried out.
Can opening up works and trial pits be undertaken?
As long as the property is not listed, it should be possible to undertake opening up works prior to the engineer’s attendance. As such, an inspection for design purposes could take anywhere from 30 minutes, to confirm the loadbearing nature of a wall, to a few hours for a whole house renovation and extension to take basic measurements.
What Is Involved In A Structural Inspection?
During the course of a structural inspection where the property has suffered damage, the engineer will be required to record the following information:
Description of the size and type of property.
Description of nature of flooring – e.g. suspended timber, ground bearing solid concrete.
Description of nature of internal and external walls – e.g. solid brickwork, lath and plaster, brick-block cavity, timber stud.
Desktop study of underlying ground conditions.
Type, size and proximity of significant vegetation surrounding the property.
Location, age, pattern and size of damage.
Time of occurrence of the damage and any signs of progression.
Signs of distortion and whether they are historic or more recent in nature.
Description of any known causes of damage.
Conclusions regarding any suspected cause of the damage – what cause is the damage consistent with?
Recommendations for any immediate works – i.e. is the damage of undue structural concern requiring works to be implemented prior to receipt of the report.
This list would apply to standard crack damage inspections as well as more insurance-related inspections such as subsidence, vehicle impact, fire, flooding.
What Is Involved In A Structural Design (Report) Inspection?
An actual structural design report is unlikely to be required for most private domestic design works. The exception may be in the case of a Licence to Alter where the freeholder / RTM company may request a report alongside the usual full written schedule of the work proposed, existing and proposed drawings / plans, structural calculations in regard to any structural alterations, a letter of comfort from the Engineer. However, this is unusual.
As such, during the course of a structural design inspection, the engineer will be required to obtain the following information:
During the course of a structural inspection where the alterations and / or extensions to the property are planned, the engineer will be required to record the following information:
Description of the size and type of property.
Description of nature of flooring – e.g. suspended timber, ground bearing solid concrete.
Description of nature of internal and external walls – e.g. solid brickwork, lath and plaster, brick-block cavity, timber stud.
Desktop study of underlying ground conditions.
Type, size and proximity of significant vegetation surrounding the property.
Findings of the opening up works and trial pits – e.g. the size and span of floor structures, the construction and therefore loadbearing nature of the walls, size and bearing of any existing beams, depth and form of the existing foundations.
Costs
If the scope is clear, then the cost of the visit will be incorporated into the cost for the works – e.g. the written confirmation of the loadbearing nature of the wall, the report on the crack damage, the relevant deliverables for the proposed structural works (drawings / sketches / calculations)
Conclusion
To allow the engineer to give as accurate an approximation as to how long the structural engineer’s inspection will take, try to be in a position to provide / advise the following:
Be clear and specific as to what you are looking to achieve.
Furnish the structural engineer with as much detail as you can at the outset (they will likely request it anyway in order to provide you with a quotation):
Surveyors report
Photos of damage
Estate agent’s floor plans
(Architects) existing and proposed drawings for structural alterations and extensions
Any access restrictions.
This will allow the engineer to be able to advise more accurately than “between 30 minutes and 3 hours” and be able to give a more accurate quotation for the overall works which would be less likely to be adjusted following the inspection.