FAQs

General Questions

Q: Will the calculations/drawings you provide be suitable for my Building Regulations application?

A: Yes. All our calculations will be suitable for your Building Regulations application

Q: Are you Qualified to provide structural calculations for me?

A: Yes. All calculations are either undertaken or approved by a chartered structural engineer.

Q: Do you have Professional Indemnity Insurance?

A: Yes. We have professional indemnity cover for £1,000,000. This should be sufficient for most small scale residential projects. Additional cover could be requested/provided for larger projects.

Q: How do I make an enquiry?

A: You can either use this link to make an enquiry, or you can send an email to This email address is being protected from spambots. You need JavaScript enabled to view it..

Q: What information do I need to provide?

A: Ideally we would request some architectural drawings for us to review. If the project is fairly simple and no architectural drawings are available then a basic dimensioned sketch, along with some photographs and a written description may be enough for us to provide calculations. If we need any further information we will email you to let you know.

Q: How much will it cost?

A: We advise you send us your drawings for us to review. Once we know exactly what the project entails we will provide you with a quotation. Typical costs for small residential projects are £55-£85 per calculation. We will clearly identify in our quotation the number of calculations required and the structural elements which need to be checked. All quotations are normally provided by a senior engineer and are accompanied with a drawing showing you our “structural scheme proposal” (link to typical scheme proposal drawing). This proposal clearly identifies all the structural elements we feel as though need to be designed.

Q: Once I have received your quotation how do I proceed with the calculations?

A: If you are happy with our quotation all we need in order to proceed with the calculations is an email response which states you are happy to proceed. This is taken as a binding agreement that you will pay and for us to proceed. Your email will need to tell us the following:-

• That you are happy for us to proceed with the calculations

• The “service” you wish to go with (i.e. standard or priority service)

• Whether you would like us to provide any of the “optional extra” services

Q: How quickly will I receive the structural calculations/drawings?

A: if you opt for our “standard” delivery service the calculations are normally delivered within 10-12 working days, however this can vary depending on the project size and current levels of workload. If you need the calculations to be delivered within 2-3 working days then you can opt for the “priority” delivery service. The project then becomes our main priority and jumps straight to the top of our to-do-list. An engineer will start work on the project immediately and in most cases the documentation will be delivered within 2-3 days. In order to engage this delivery service we charge an additional 50% surcharge on top of our standard fee.

Q: When do I have to pay for the calculations?

A: Upon giving us the go-ahead to undertake the calculations for your project we will send you an invoice via email. We will make a start on the calculations as soon as one of our engineers becomes available (usually within 1-2 days), but we will not release the final approved documents until we have received payment in full. Payment can be made straight away or you can ask us to let you know when the calculations/documentation is finished and is ready to be sent. We will then send you an email reminder for you to pay.

Q: How can I make payment?

A: Payments can be made either by cash, cheque, BACS, internet bank transfer or you can give us a call and pay over the telephone by debit card. If you want to pay by BACS/internet bank transfer then you will find our bank details on the invoice we send. Please note that if you pay by cheque then the calculations will not be sent to you until the money is in our account. If you are in a rush to receive the documentation we would advise you against paying by cheque.

Q: How do I communicate with the engineer who is looking at my project?

A: You will be sent an invitation via email to log into our project management software. Once you have accessed you project area you will be able to communicate with the engineers working on your project. You will also be able to upload any new information such as pictures or drawings which may be helpful or important to the project.

Q: How do you ensure Quality?

A: See our Quality Assurance page

Q: What will you send to me?

A: All our calculations/drawings/documentation are issued via email in pdf format. Hard copies of documentation can be provided but will be subject to an additional cost.

Q: What if Building Control have questions regarding our calculations?

A: Although it is very uncommon, sometimes the local councils checking engineer may have some comments/questions regarding our calculations. If so, we will answer the questions and if necessary revise our calculations/documentation free of charge until the checking engineer is satisfied. However, if the checking engineer asks for additional calculations which have not been covered within our quotation, or asks for calculations which you originaly asked us not to provide, then provision of such calculations may be subject to additional costs.

Technical Questions

Q: Why do I need a windpost in my wall panel (between 2No windows)?

A: Aside from designing a structure to withstand vertical loads (for beams, foundations etc), it is also the responsibility of the structural engineer to ensure that a property has sufficient “lateral stability” (i.e. resistance to horizontal loads such as wind loading). Lateral stability must be considered to make sure a building doesn’t suffer undue deflections/horizontal displacements which could either result in structural/decorative cracking and/or structural collapse.

When you have a wall panel which contains two openings for either windows or doors, you develop a weak point in the masonry between the two openings. The weak point is created as the sides of the panel are unsupported (i.e. by a perpendicular running wall panel or a post). This changes the behaviour of the masonry in this area when subjected to wind loading. The panel now “spans vertically” which isn’t an ideal arrangement for masonry as you get a “plane of weakness” along the bed joint.

It is often difficult to prove (via calculation) that these vertically spanning masonry panels are capable of withstanding the applied wind loading. Normally in these circumstances we would look to reinforce the masonry using one of the following methods:-

• Steel Windpost:- this is a small “box section” steel post which can be hidden within the depth of the wall, bracing it against wind loading and providing the client with an architecturally pleasing flush wall finish.

• Timber Windpost:- this works in a similar way to the steel windpost, but instead of being concealed within the wall it needs to be screwed to the inner side of the wall, so you don’t get a flush wall finish. However, this is often found to be a cheaper solution, and clients tend to opt for it when they are not too bothered about having a flush wall finish.

• Masonry Pier:- another relatively cheap alternative is to back the wall panel with a small masonry pier. The length of pier is normally in the region of 600mm, which obviously eats into the amount of useable floor space.

Although we offer the service as an “optional extra” we would highly recommend you have us provide calculations for one of the above (if we suggest it in our quotation). This service is offered as an “optional extra” as not all Local Council Building Control Departments request these types of wall panels to be checked. Although the applied wind loading is unlikely to cause a structural collapse, deflections in the masonry panel could lead to cracking in the internal plaster and wall finishes. Feel free to give us a call if you need any clarification/advice on the above.

Q: Why do I need a windpost (to support a small masonry pier)?

A: Aside from designing a structure to withstand vertical loads (for beams, foundations etc), it is also the responsibility of the structural engineer to ensure that a property has sufficient “lateral stability” (i.e. resistance to horizontal loads such as wind loading). Lateral stability must be considered to make sure a building doesn’t suffer undue deflections/horizontal displacements which could either result in structural/decorative cracking and/or structural collapse.

Masonry piers are normally used to support the ends of wall panels against wind loading. The Building Regulations suggest a minimum masonry pier size of 665mm, which will be suitable to support most wind loads across the UK. If you have a masonry pier in your project which is smaller than this dimension then a calculation should be provide to make sure the pier can withstand the applied wind loading.

If the pier is quite small, we might use our engineering judgement to suggest that a steel post be used to restrain the masonry/panel against wind loading. Alternatively, we can run a design calculation to see what size of masonry pier is required in order to resist the applied wind loading.

Q: Why do I need to check a wall panel for wind loading?

A: Aside from designing a structure to withstand vertical loads (for beams, foundations etc), it is also the responsibility of the structural engineer to ensure that a property has sufficient “lateral stability” (i.e. resistance to horizontal loads such as wind loading). Lateral stability must be considered to make sure a building doesn’t suffer undue deflections/horizontal displacements which could either result in structural/decorative cracking and/or structural collapse.

When you have a long spanning wall panel (>6.5m), the masonry within the panel begins to act differently when it is subjected to wind loading. The British Standards Code of Practise for the Design of Masonry suggests a “limiting dimension” for a masonry wall panel of 50d, which for a standard cavity wall is 6.65m. If one of the masonry panels in your project is greater than this then it should be checked to make sure it can withstand the applied wind loads.

Masonry has much greater strength properties when it “spans horizontally” compared to when it “spans vertically”. When a masonry wall panel spans a long distance, the centre of the panel can sometimes span vertically rather than horizontally, and you get a plane of weakness along the masonry bed-joint. This could cause excessive deflection in the masonry wall panel, which could lead to unwanted cracks appearing in the masonry or internal decorations. In extreme circumstances, excessive panel deflections could also lead to structural collapse.


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   Second Floor Office, King Street Buildings
16-18 King Street, Manchester, M2 6AG

   info@porthousedean.co.uk
   0161 820 3230

PorthouseDean is the trading name of PorthouseDean Limited.

Registered at Company House in England.
Company No: 08086677